1 /* 2 ** 2001-09-15 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ************************************************************************* 12 ** This header file defines the interface that the SQLite library 13 ** presents to client programs. If a C-function, structure, datatype, 14 ** or constant definition does not appear in this file, then it is 15 ** not a published API of SQLite, is subject to change without 16 ** notice, and should not be referenced by programs that use SQLite. 17 ** 18 ** Some of the definitions that are in this file are marked as 19 ** "experimental". Experimental interfaces are normally new 20 ** features recently added to SQLite. We do not anticipate changes 21 ** to experimental interfaces but reserve the right to make minor changes 22 ** if experience from use "in the wild" suggest such changes are prudent. 23 ** 24 ** The official C-language API documentation for SQLite is derived 25 ** from comments in this file. This file is the authoritative source 26 ** on how SQLite interfaces are supposed to operate. 27 ** 28 ** The name of this file under configuration management is "sqlite.h.in". 29 ** The makefile makes some minor changes to this file (such as inserting 30 ** the version number) and changes its name to "sqlite3.h" as 31 ** part of the build process. 32 */ 33 #ifndef SQLITE3_H 34 #define SQLITE3_H 35 #include <stdarg.h> /* Needed for the definition of va_list */ 36 37 /* 38 ** Make sure we can call this stuff from C++. 39 */ 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 45 /* 46 ** Facilitate override of interface linkage and calling conventions. 47 ** Be aware that these macros may not be used within this particular 48 ** translation of the amalgamation and its associated header file. 49 ** 50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51 ** compiler that the target identifier should have external linkage. 52 ** 53 ** The SQLITE_CDECL macro is used to set the calling convention for 54 ** public functions that accept a variable number of arguments. 55 ** 56 ** The SQLITE_APICALL macro is used to set the calling convention for 57 ** public functions that accept a fixed number of arguments. 58 ** 59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60 ** 61 ** The SQLITE_CALLBACK macro is used to set the calling convention for 62 ** function pointers. 63 ** 64 ** The SQLITE_SYSAPI macro is used to set the calling convention for 65 ** functions provided by the operating system. 66 ** 67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68 ** SQLITE_SYSAPI macros are used only when building for environments 69 ** that require non-default calling conventions. 70 */ 71 #ifndef SQLITE_EXTERN 72 # define SQLITE_EXTERN extern 73 #endif 74 #ifndef SQLITE_API 75 # define SQLITE_API 76 #endif 77 #ifndef SQLITE_CDECL 78 # define SQLITE_CDECL 79 #endif 80 #ifndef SQLITE_APICALL 81 # define SQLITE_APICALL 82 #endif 83 #ifndef SQLITE_STDCALL 84 # define SQLITE_STDCALL SQLITE_APICALL 85 #endif 86 #ifndef SQLITE_CALLBACK 87 # define SQLITE_CALLBACK 88 #endif 89 #ifndef SQLITE_SYSAPI 90 # define SQLITE_SYSAPI 91 #endif 92 93 /* 94 ** These no-op macros are used in front of interfaces to mark those 95 ** interfaces as either deprecated or experimental. New applications 96 ** should not use deprecated interfaces - they are supported for backwards 97 ** compatibility only. Application writers should be aware that 98 ** experimental interfaces are subject to change in point releases. 99 ** 100 ** These macros used to resolve to various kinds of compiler magic that 101 ** would generate warning messages when they were used. But that 102 ** compiler magic ended up generating such a flurry of bug reports 103 ** that we have taken it all out and gone back to using simple 104 ** noop macros. 105 */ 106 #define SQLITE_DEPRECATED 107 #define SQLITE_EXPERIMENTAL 108 109 /* 110 ** Ensure these symbols were not defined by some previous header file. 111 */ 112 #ifdef SQLITE_VERSION 113 # undef SQLITE_VERSION 114 #endif 115 #ifdef SQLITE_VERSION_NUMBER 116 # undef SQLITE_VERSION_NUMBER 117 #endif 118 119 /* 120 ** CAPI3REF: Compile-Time Library Version Numbers 121 ** 122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123 ** evaluates to a string literal that is the SQLite version in the 124 ** format "X.Y.Z" where X is the major version number (always 3 for 125 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128 ** numbers used in [SQLITE_VERSION].)^ 129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130 ** be larger than the release from which it is derived. Either Y will 131 ** be held constant and Z will be incremented or else Y will be incremented 132 ** and Z will be reset to zero. 133 ** 134 ** Since [version 3.6.18] ([dateof:3.6.18]), 135 ** SQLite source code has been stored in the 136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138 ** a string which identifies a particular check-in of SQLite 139 ** within its configuration management system. ^The SQLITE_SOURCE_ID 140 ** string contains the date and time of the check-in (UTC) and a SHA1 141 ** or SHA3-256 hash of the entire source tree. If the source code has 142 ** been edited in any way since it was last checked in, then the last 143 ** four hexadecimal digits of the hash may be modified. 144 ** 145 ** See also: [sqlite3_libversion()], 146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147 ** [sqlite_version()] and [sqlite_source_id()]. 148 */ 149 #define SQLITE_VERSION "3.44.4" 150 #define SQLITE_VERSION_NUMBER 3044004 151 #define SQLITE_SOURCE_ID "2025-02-19 00:18:53 f1e31fd9961ac82535a5d0702b127d84de8ca21d4df1c51c73e078ea0ad4afa8" 152 153 /* 154 ** CAPI3REF: Run-Time Library Version Numbers 155 ** KEYWORDS: sqlite3_version sqlite3_sourceid 156 ** 157 ** These interfaces provide the same information as the [SQLITE_VERSION], 158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159 ** but are associated with the library instead of the header file. ^(Cautious 160 ** programmers might include assert() statements in their application to 161 ** verify that values returned by these interfaces match the macros in 162 ** the header, and thus ensure that the application is 163 ** compiled with matching library and header files. 164 ** 165 ** <blockquote><pre> 166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169 ** </pre></blockquote>)^ 170 ** 171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172 ** macro. ^The sqlite3_libversion() function returns a pointer to the 173 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 174 ** function is provided for use in DLLs since DLL users usually do not have 175 ** direct access to string constants within the DLL. ^The 176 ** sqlite3_libversion_number() function returns an integer equal to 177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178 ** a pointer to a string constant whose value is the same as the 179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180 ** using an edited copy of [the amalgamation], then the last four characters 181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182 ** 183 ** See also: [sqlite_version()] and [sqlite_source_id()]. 184 */ 185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 186 SQLITE_API const char *sqlite3_libversion(void); 187 SQLITE_API const char *sqlite3_sourceid(void); 188 SQLITE_API int sqlite3_libversion_number(void); 189 190 /* 191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192 ** 193 ** ^The sqlite3_compileoption_used() function returns 0 or 1 194 ** indicating whether the specified option was defined at 195 ** compile time. ^The SQLITE_ prefix may be omitted from the 196 ** option name passed to sqlite3_compileoption_used(). 197 ** 198 ** ^The sqlite3_compileoption_get() function allows iterating 199 ** over the list of options that were defined at compile time by 200 ** returning the N-th compile time option string. ^If N is out of range, 201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202 ** prefix is omitted from any strings returned by 203 ** sqlite3_compileoption_get(). 204 ** 205 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 206 ** and sqlite3_compileoption_get() may be omitted by specifying the 207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208 ** 209 ** See also: SQL functions [sqlite_compileoption_used()] and 210 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 211 */ 212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 214 SQLITE_API const char *sqlite3_compileoption_get(int N); 215 #else 216 # define sqlite3_compileoption_used(X) 0 217 # define sqlite3_compileoption_get(X) ((void*)0) 218 #endif 219 220 /* 221 ** CAPI3REF: Test To See If The Library Is Threadsafe 222 ** 223 ** ^The sqlite3_threadsafe() function returns zero if and only if 224 ** SQLite was compiled with mutexing code omitted due to the 225 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 226 ** 227 ** SQLite can be compiled with or without mutexes. When 228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229 ** are enabled and SQLite is threadsafe. When the 230 ** [SQLITE_THREADSAFE] macro is 0, 231 ** the mutexes are omitted. Without the mutexes, it is not safe 232 ** to use SQLite concurrently from more than one thread. 233 ** 234 ** Enabling mutexes incurs a measurable performance penalty. 235 ** So if speed is of utmost importance, it makes sense to disable 236 ** the mutexes. But for maximum safety, mutexes should be enabled. 237 ** ^The default behavior is for mutexes to be enabled. 238 ** 239 ** This interface can be used by an application to make sure that the 240 ** version of SQLite that it is linking against was compiled with 241 ** the desired setting of the [SQLITE_THREADSAFE] macro. 242 ** 243 ** This interface only reports on the compile-time mutex setting 244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246 ** can be fully or partially disabled using a call to [sqlite3_config()] 247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249 ** sqlite3_threadsafe() function shows only the compile-time setting of 250 ** thread safety, not any run-time changes to that setting made by 251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252 ** is unchanged by calls to sqlite3_config().)^ 253 ** 254 ** See the [threading mode] documentation for additional information. 255 */ 256 SQLITE_API int sqlite3_threadsafe(void); 257 258 /* 259 ** CAPI3REF: Database Connection Handle 260 ** KEYWORDS: {database connection} {database connections} 261 ** 262 ** Each open SQLite database is represented by a pointer to an instance of 263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266 ** and [sqlite3_close_v2()] are its destructors. There are many other 267 ** interfaces (such as 268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 270 ** sqlite3 object. 271 */ 272 typedef struct sqlite3 sqlite3; 273 274 /* 275 ** CAPI3REF: 64-Bit Integer Types 276 ** KEYWORDS: sqlite_int64 sqlite_uint64 277 ** 278 ** Because there is no cross-platform way to specify 64-bit integer types 279 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 280 ** 281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283 ** compatibility only. 284 ** 285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 288 ** between 0 and +18446744073709551615 inclusive. 289 */ 290 #ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292 # ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294 # else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296 # endif 297 #elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300 #else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303 #endif 304 typedef sqlite_int64 sqlite3_int64; 305 typedef sqlite_uint64 sqlite3_uint64; 306 307 /* 308 ** If compiling for a processor that lacks floating point support, 309 ** substitute integer for floating-point. 310 */ 311 #ifdef SQLITE_OMIT_FLOATING_POINT 312 # define double sqlite3_int64 313 #endif 314 315 /* 316 ** CAPI3REF: Closing A Database Connection 317 ** DESTRUCTOR: sqlite3 318 ** 319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320 ** for the [sqlite3] object. 321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322 ** the [sqlite3] object is successfully destroyed and all associated 323 ** resources are deallocated. 324 ** 325 ** Ideally, applications should [sqlite3_finalize | finalize] all 326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328 ** with the [sqlite3] object prior to attempting to close the object. 329 ** ^If the database connection is associated with unfinalized prepared 330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331 ** sqlite3_close() will leave the database connection open and return 332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335 ** connection immediately, it marks the database connection as an unusable 336 ** "zombie" and makes arrangements to automatically deallocate the database 337 ** connection after all prepared statements are finalized, all BLOB handles 338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface 339 ** is intended for use with host languages that are garbage collected, and 340 ** where the order in which destructors are called is arbitrary. 341 ** 342 ** ^If an [sqlite3] object is destroyed while a transaction is open, 343 ** the transaction is automatically rolled back. 344 ** 345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346 ** must be either a NULL 347 ** pointer or an [sqlite3] object pointer obtained 348 ** from [sqlite3_open()], [sqlite3_open16()], or 349 ** [sqlite3_open_v2()], and not previously closed. 350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351 ** argument is a harmless no-op. 352 */ 353 SQLITE_API int sqlite3_close(sqlite3*); 354 SQLITE_API int sqlite3_close_v2(sqlite3*); 355 356 /* 357 ** The type for a callback function. 358 ** This is legacy and deprecated. It is included for historical 359 ** compatibility and is not documented. 360 */ 361 typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363 /* 364 ** CAPI3REF: One-Step Query Execution Interface 365 ** METHOD: sqlite3 366 ** 367 ** The sqlite3_exec() interface is a convenience wrapper around 368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369 ** that allows an application to run multiple statements of SQL 370 ** without having to use a lot of C code. 371 ** 372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373 ** semicolon-separate SQL statements passed into its 2nd argument, 374 ** in the context of the [database connection] passed in as its 1st 375 ** argument. ^If the callback function of the 3rd argument to 376 ** sqlite3_exec() is not NULL, then it is invoked for each result row 377 ** coming out of the evaluated SQL statements. ^The 4th argument to 378 ** sqlite3_exec() is relayed through to the 1st argument of each 379 ** callback invocation. ^If the callback pointer to sqlite3_exec() 380 ** is NULL, then no callback is ever invoked and result rows are 381 ** ignored. 382 ** 383 ** ^If an error occurs while evaluating the SQL statements passed into 384 ** sqlite3_exec(), then execution of the current statement stops and 385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386 ** is not NULL then any error message is written into memory obtained 387 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 388 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 389 ** on error message strings returned through the 5th parameter of 390 ** sqlite3_exec() after the error message string is no longer needed. 391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393 ** NULL before returning. 394 ** 395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396 ** routine returns SQLITE_ABORT without invoking the callback again and 397 ** without running any subsequent SQL statements. 398 ** 399 ** ^The 2nd argument to the sqlite3_exec() callback function is the 400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401 ** callback is an array of pointers to strings obtained as if from 402 ** [sqlite3_column_text()], one for each column. ^If an element of a 403 ** result row is NULL then the corresponding string pointer for the 404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405 ** sqlite3_exec() callback is an array of pointers to strings where each 406 ** entry represents the name of corresponding result column as obtained 407 ** from [sqlite3_column_name()]. 408 ** 409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410 ** to an empty string, or a pointer that contains only whitespace and/or 411 ** SQL comments, then no SQL statements are evaluated and the database 412 ** is not changed. 413 ** 414 ** Restrictions: 415 ** 416 ** <ul> 417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418 ** is a valid and open [database connection]. 419 ** <li> The application must not close the [database connection] specified by 420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421 ** <li> The application must not modify the SQL statement text passed into 422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423 ** </ul> 424 */ 425 SQLITE_API int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431 ); 432 433 /* 434 ** CAPI3REF: Result Codes 435 ** KEYWORDS: {result code definitions} 436 ** 437 ** Many SQLite functions return an integer result code from the set shown 438 ** here in order to indicate success or failure. 439 ** 440 ** New error codes may be added in future versions of SQLite. 441 ** 442 ** See also: [extended result code definitions] 443 */ 444 #define SQLITE_OK 0 /* Successful result */ 445 /* beginning-of-error-codes */ 446 #define SQLITE_ERROR 1 /* Generic error */ 447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448 #define SQLITE_PERM 3 /* Access permission denied */ 449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450 #define SQLITE_BUSY 5 /* The database file is locked */ 451 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 452 #define SQLITE_NOMEM 7 /* A malloc() failed */ 453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461 #define SQLITE_EMPTY 16 /* Internal use only */ 462 #define SQLITE_SCHEMA 17 /* The database schema changed */ 463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 466 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468 #define SQLITE_AUTH 23 /* Authorization denied */ 469 #define SQLITE_FORMAT 24 /* Not used */ 470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476 /* end-of-error-codes */ 477 478 /* 479 ** CAPI3REF: Extended Result Codes 480 ** KEYWORDS: {extended result code definitions} 481 ** 482 ** In its default configuration, SQLite API routines return one of 30 integer 483 ** [result codes]. However, experience has shown that many of 484 ** these result codes are too coarse-grained. They do not provide as 485 ** much information about problems as programmers might like. In an effort to 486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487 ** and later) include 488 ** support for additional result codes that provide more detailed information 489 ** about errors. These [extended result codes] are enabled or disabled 490 ** on a per database connection basis using the 491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 492 ** the most recent error can be obtained using 493 ** [sqlite3_extended_errcode()]. 494 */ 495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8)) 532 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 533 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 534 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 535 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 536 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 537 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 538 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 539 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 540 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 541 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 542 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 543 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 544 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 545 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 546 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 547 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 548 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 549 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 550 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 551 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 552 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 553 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 554 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 555 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 556 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 557 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 558 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 559 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 560 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 561 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 562 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 563 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 564 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 565 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 566 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 567 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8)) 568 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 569 #define SQLITE_WARNING_NOTCOMPRESSDB (SQLITE_WARNING | (3<<8)) 570 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 571 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 572 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 573 574 /* 575 ** CAPI3REF: Flags For File Open Operations 576 ** 577 ** These bit values are intended for use in the 578 ** 3rd parameter to the [sqlite3_open_v2()] interface and 579 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 580 ** 581 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 582 ** used as the third argument to the [sqlite3_open_v2()] interface. 583 ** The other flags have historically been ignored by sqlite3_open_v2(), 584 ** though future versions of SQLite might change so that an error is 585 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 586 ** Applications should not depend on the historical behavior. 587 ** 588 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 589 ** [sqlite3_open_v2()] does *not* cause the underlying database file 590 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 591 ** [sqlite3_open_v2()] has historically be a no-op and might become an 592 ** error in future versions of SQLite. 593 */ 594 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 595 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 596 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 597 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 598 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 599 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 600 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 601 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 602 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 603 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 604 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 605 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 606 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 607 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 608 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 609 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 611 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 613 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 614 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 615 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 616 617 /* Reserved: 0x00F00000 */ 618 /* Legacy compatibility: */ 619 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 620 621 622 /* 623 ** CAPI3REF: Device Characteristics 624 ** 625 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 626 ** object returns an integer which is a vector of these 627 ** bit values expressing I/O characteristics of the mass storage 628 ** device that holds the file that the [sqlite3_io_methods] 629 ** refers to. 630 ** 631 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 632 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 633 ** mean that writes of blocks that are nnn bytes in size and 634 ** are aligned to an address which is an integer multiple of 635 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 636 ** that when data is appended to a file, the data is appended 637 ** first then the size of the file is extended, never the other 638 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 639 ** information is written to disk in the same order as calls 640 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 641 ** after reboot following a crash or power loss, the only bytes in a 642 ** file that were written at the application level might have changed 643 ** and that adjacent bytes, even bytes within the same sector are 644 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 645 ** flag indicates that a file cannot be deleted when open. The 646 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 647 ** read-only media and cannot be changed even by processes with 648 ** elevated privileges. 649 ** 650 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 651 ** filesystem supports doing multiple write operations atomically when those 652 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 653 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 654 */ 655 #define SQLITE_IOCAP_ATOMIC 0x00000001 656 #define SQLITE_IOCAP_ATOMIC512 0x00000002 657 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 658 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 659 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 660 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 661 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 662 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 663 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 664 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 665 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 666 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 667 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 668 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 669 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 670 671 /* 672 ** CAPI3REF: File Locking Levels 673 ** 674 ** SQLite uses one of these integer values as the second 675 ** argument to calls it makes to the xLock() and xUnlock() methods 676 ** of an [sqlite3_io_methods] object. These values are ordered from 677 ** lest restrictive to most restrictive. 678 ** 679 ** The argument to xLock() is always SHARED or higher. The argument to 680 ** xUnlock is either SHARED or NONE. 681 */ 682 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 683 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 684 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 685 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 686 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 687 688 /* 689 ** CAPI3REF: Synchronization Type Flags 690 ** 691 ** When SQLite invokes the xSync() method of an 692 ** [sqlite3_io_methods] object it uses a combination of 693 ** these integer values as the second argument. 694 ** 695 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 696 ** sync operation only needs to flush data to mass storage. Inode 697 ** information need not be flushed. If the lower four bits of the flag 698 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 699 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 700 ** to use Mac OS X style fullsync instead of fsync(). 701 ** 702 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 703 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 704 ** settings. The [synchronous pragma] determines when calls to the 705 ** xSync VFS method occur and applies uniformly across all platforms. 706 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 707 ** energetic or rigorous or forceful the sync operations are and 708 ** only make a difference on Mac OSX for the default SQLite code. 709 ** (Third-party VFS implementations might also make the distinction 710 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 711 ** operating systems natively supported by SQLite, only Mac OSX 712 ** cares about the difference.) 713 */ 714 #define SQLITE_SYNC_NORMAL 0x00002 715 #define SQLITE_SYNC_FULL 0x00003 716 #define SQLITE_SYNC_DATAONLY 0x00010 717 718 /* 719 ** CAPI3REF: OS Interface Open File Handle 720 ** 721 ** An [sqlite3_file] object represents an open file in the 722 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 723 ** implementations will 724 ** want to subclass this object by appending additional fields 725 ** for their own use. The pMethods entry is a pointer to an 726 ** [sqlite3_io_methods] object that defines methods for performing 727 ** I/O operations on the open file. 728 */ 729 typedef struct sqlite3_file sqlite3_file; 730 struct sqlite3_file { 731 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 732 }; 733 734 /* 735 ** CAPI3REF: OS Interface File Virtual Methods Object 736 ** 737 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 738 ** [sqlite3_file] object (or, more commonly, a subclass of the 739 ** [sqlite3_file] object) with a pointer to an instance of this object. 740 ** This object defines the methods used to perform various operations 741 ** against the open file represented by the [sqlite3_file] object. 742 ** 743 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 744 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 745 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 746 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 747 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 748 ** to NULL. 749 ** 750 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 751 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 752 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 753 ** flag may be ORed in to indicate that only the data of the file 754 ** and not its inode needs to be synced. 755 ** 756 ** The integer values to xLock() and xUnlock() are one of 757 ** <ul> 758 ** <li> [SQLITE_LOCK_NONE], 759 ** <li> [SQLITE_LOCK_SHARED], 760 ** <li> [SQLITE_LOCK_RESERVED], 761 ** <li> [SQLITE_LOCK_PENDING], or 762 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 763 ** </ul> 764 ** xLock() upgrades the database file lock. In other words, xLock() moves the 765 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 766 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 767 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 768 ** requested lock, then the call to xLock() is a no-op. 769 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 770 * If the lock is already at or below the requested lock state, then the call 771 ** to xUnlock() is a no-op. 772 ** The xCheckReservedLock() method checks whether any database connection, 773 ** either in this process or in some other process, is holding a RESERVED, 774 ** PENDING, or EXCLUSIVE lock on the file. It returns true 775 ** if such a lock exists and false otherwise. 776 ** 777 ** The xFileControl() method is a generic interface that allows custom 778 ** VFS implementations to directly control an open file using the 779 ** [sqlite3_file_control()] interface. The second "op" argument is an 780 ** integer opcode. The third argument is a generic pointer intended to 781 ** point to a structure that may contain arguments or space in which to 782 ** write return values. Potential uses for xFileControl() might be 783 ** functions to enable blocking locks with timeouts, to change the 784 ** locking strategy (for example to use dot-file locks), to inquire 785 ** about the status of a lock, or to break stale locks. The SQLite 786 ** core reserves all opcodes less than 100 for its own use. 787 ** A [file control opcodes | list of opcodes] less than 100 is available. 788 ** Applications that define a custom xFileControl method should use opcodes 789 ** greater than 100 to avoid conflicts. VFS implementations should 790 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 791 ** recognize. 792 ** 793 ** The xSectorSize() method returns the sector size of the 794 ** device that underlies the file. The sector size is the 795 ** minimum write that can be performed without disturbing 796 ** other bytes in the file. The xDeviceCharacteristics() 797 ** method returns a bit vector describing behaviors of the 798 ** underlying device: 799 ** 800 ** <ul> 801 ** <li> [SQLITE_IOCAP_ATOMIC] 802 ** <li> [SQLITE_IOCAP_ATOMIC512] 803 ** <li> [SQLITE_IOCAP_ATOMIC1K] 804 ** <li> [SQLITE_IOCAP_ATOMIC2K] 805 ** <li> [SQLITE_IOCAP_ATOMIC4K] 806 ** <li> [SQLITE_IOCAP_ATOMIC8K] 807 ** <li> [SQLITE_IOCAP_ATOMIC16K] 808 ** <li> [SQLITE_IOCAP_ATOMIC32K] 809 ** <li> [SQLITE_IOCAP_ATOMIC64K] 810 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 811 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 812 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 813 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 814 ** <li> [SQLITE_IOCAP_IMMUTABLE] 815 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 816 ** </ul> 817 ** 818 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 819 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 820 ** mean that writes of blocks that are nnn bytes in size and 821 ** are aligned to an address which is an integer multiple of 822 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 823 ** that when data is appended to a file, the data is appended 824 ** first then the size of the file is extended, never the other 825 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 826 ** information is written to disk in the same order as calls 827 ** to xWrite(). 828 ** 829 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 830 ** in the unread portions of the buffer with zeros. A VFS that 831 ** fails to zero-fill short reads might seem to work. However, 832 ** failure to zero-fill short reads will eventually lead to 833 ** database corruption. 834 */ 835 typedef struct sqlite3_io_methods sqlite3_io_methods; 836 struct sqlite3_io_methods { 837 int iVersion; 838 int (*xClose)(sqlite3_file*); 839 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 840 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 841 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 842 int (*xSync)(sqlite3_file*, int flags); 843 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 844 int (*xLock)(sqlite3_file*, int); 845 int (*xUnlock)(sqlite3_file*, int); 846 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 847 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 848 int (*xSectorSize)(sqlite3_file*); 849 int (*xDeviceCharacteristics)(sqlite3_file*); 850 /* Methods above are valid for version 1 */ 851 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 852 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 853 void (*xShmBarrier)(sqlite3_file*); 854 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 855 /* Methods above are valid for version 2 */ 856 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 857 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 858 /* Methods above are valid for version 3 */ 859 /* Additional methods may be added in future releases */ 860 }; 861 862 /* 863 ** CAPI3REF: Standard File Control Opcodes 864 ** KEYWORDS: {file control opcodes} {file control opcode} 865 ** 866 ** These integer constants are opcodes for the xFileControl method 867 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 868 ** interface. 869 ** 870 ** <ul> 871 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 872 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 873 ** opcode causes the xFileControl method to write the current state of 874 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 875 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 876 ** into an integer that the pArg argument points to. 877 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 878 ** 879 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 880 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 881 ** layer a hint of how large the database file will grow to be during the 882 ** current transaction. This hint is not guaranteed to be accurate but it 883 ** is often close. The underlying VFS might choose to preallocate database 884 ** file space based on this hint in order to help writes to the database 885 ** file run faster. 886 ** 887 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 888 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 889 ** implements [sqlite3_deserialize()] to set an upper bound on the size 890 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 891 ** If the integer pointed to is negative, then it is filled in with the 892 ** current limit. Otherwise the limit is set to the larger of the value 893 ** of the integer pointed to and the current database size. The integer 894 ** pointed to is set to the new limit. 895 ** 896 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 897 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 898 ** extends and truncates the database file in chunks of a size specified 899 ** by the user. The fourth argument to [sqlite3_file_control()] should 900 ** point to an integer (type int) containing the new chunk-size to use 901 ** for the nominated database. Allocating database file space in large 902 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 903 ** improve performance on some systems. 904 ** 905 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 906 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 907 ** to the [sqlite3_file] object associated with a particular database 908 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 909 ** 910 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 911 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 912 ** to the [sqlite3_file] object associated with the journal file (either 913 ** the [rollback journal] or the [write-ahead log]) for a particular database 914 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 915 ** 916 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 917 ** No longer in use. 918 ** 919 ** <li>[[SQLITE_FCNTL_SYNC]] 920 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 921 ** sent to the VFS immediately before the xSync method is invoked on a 922 ** database file descriptor. Or, if the xSync method is not invoked 923 ** because the user has configured SQLite with 924 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 925 ** of the xSync method. In most cases, the pointer argument passed with 926 ** this file-control is NULL. However, if the database file is being synced 927 ** as part of a multi-database commit, the argument points to a nul-terminated 928 ** string containing the transactions super-journal file name. VFSes that 929 ** do not need this signal should silently ignore this opcode. Applications 930 ** should not call [sqlite3_file_control()] with this opcode as doing so may 931 ** disrupt the operation of the specialized VFSes that do require it. 932 ** 933 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 934 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 935 ** and sent to the VFS after a transaction has been committed immediately 936 ** but before the database is unlocked. VFSes that do not need this signal 937 ** should silently ignore this opcode. Applications should not call 938 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 939 ** operation of the specialized VFSes that do require it. 940 ** 941 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 942 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 943 ** retry counts and intervals for certain disk I/O operations for the 944 ** windows [VFS] in order to provide robustness in the presence of 945 ** anti-virus programs. By default, the windows VFS will retry file read, 946 ** file write, and file delete operations up to 10 times, with a delay 947 ** of 25 milliseconds before the first retry and with the delay increasing 948 ** by an additional 25 milliseconds with each subsequent retry. This 949 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 950 ** to be adjusted. The values are changed for all database connections 951 ** within the same process. The argument is a pointer to an array of two 952 ** integers where the first integer is the new retry count and the second 953 ** integer is the delay. If either integer is negative, then the setting 954 ** is not changed but instead the prior value of that setting is written 955 ** into the array entry, allowing the current retry settings to be 956 ** interrogated. The zDbName parameter is ignored. 957 ** 958 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 959 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 960 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 961 ** write ahead log ([WAL file]) and shared memory 962 ** files used for transaction control 963 ** are automatically deleted when the latest connection to the database 964 ** closes. Setting persistent WAL mode causes those files to persist after 965 ** close. Persisting the files is useful when other processes that do not 966 ** have write permission on the directory containing the database file want 967 ** to read the database file, as the WAL and shared memory files must exist 968 ** in order for the database to be readable. The fourth parameter to 969 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 970 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 971 ** WAL mode. If the integer is -1, then it is overwritten with the current 972 ** WAL persistence setting. 973 ** 974 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 975 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 976 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 977 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 978 ** xDeviceCharacteristics methods. The fourth parameter to 979 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 980 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 981 ** mode. If the integer is -1, then it is overwritten with the current 982 ** zero-damage mode setting. 983 ** 984 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 985 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 986 ** a write transaction to indicate that, unless it is rolled back for some 987 ** reason, the entire database file will be overwritten by the current 988 ** transaction. This is used by VACUUM operations. 989 ** 990 ** <li>[[SQLITE_FCNTL_VFSNAME]] 991 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 992 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 993 ** final bottom-level VFS are written into memory obtained from 994 ** [sqlite3_malloc()] and the result is stored in the char* variable 995 ** that the fourth parameter of [sqlite3_file_control()] points to. 996 ** The caller is responsible for freeing the memory when done. As with 997 ** all file-control actions, there is no guarantee that this will actually 998 ** do anything. Callers should initialize the char* variable to a NULL 999 ** pointer in case this file-control is not implemented. This file-control 1000 ** is intended for diagnostic use only. 1001 ** 1002 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1003 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1004 ** [VFSes] currently in use. ^(The argument X in 1005 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1006 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1007 ** to a pointer to the top-level VFS.)^ 1008 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1009 ** upper-most shim only. 1010 ** 1011 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1012 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1013 ** file control is sent to the open [sqlite3_file] object corresponding 1014 ** to the database file to which the pragma statement refers. ^The argument 1015 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1016 ** pointers to strings (char**) in which the second element of the array 1017 ** is the name of the pragma and the third element is the argument to the 1018 ** pragma or NULL if the pragma has no argument. ^The handler for an 1019 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1020 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1021 ** or the equivalent and that string will become the result of the pragma or 1022 ** the error message if the pragma fails. ^If the 1023 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1024 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1025 ** file control returns [SQLITE_OK], then the parser assumes that the 1026 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1027 ** prepared statement if result string is NULL, or that returns a copy 1028 ** of the result string if the string is non-NULL. 1029 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1030 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1031 ** that the VFS encountered an error while handling the [PRAGMA] and the 1032 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1033 ** file control occurs at the beginning of pragma statement analysis and so 1034 ** it is able to override built-in [PRAGMA] statements. 1035 ** 1036 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1037 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1038 ** file-control may be invoked by SQLite on the database file handle 1039 ** shortly after it is opened in order to provide a custom VFS with access 1040 ** to the connection's busy-handler callback. The argument is of type (void**) 1041 ** - an array of two (void *) values. The first (void *) actually points 1042 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1043 ** busy-handler, this function should be invoked with the second (void *) in 1044 ** the array as the only argument. If it returns non-zero, then the operation 1045 ** should be retried. If it returns zero, the custom VFS should abandon the 1046 ** current operation. 1047 ** 1048 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1049 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1050 ** to have SQLite generate a 1051 ** temporary filename using the same algorithm that is followed to generate 1052 ** temporary filenames for TEMP tables and other internal uses. The 1053 ** argument should be a char** which will be filled with the filename 1054 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1055 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1056 ** 1057 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1058 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1059 ** maximum number of bytes that will be used for memory-mapped I/O. 1060 ** The argument is a pointer to a value of type sqlite3_int64 that 1061 ** is an advisory maximum number of bytes in the file to memory map. The 1062 ** pointer is overwritten with the old value. The limit is not changed if 1063 ** the value originally pointed to is negative, and so the current limit 1064 ** can be queried by passing in a pointer to a negative number. This 1065 ** file-control is used internally to implement [PRAGMA mmap_size]. 1066 ** 1067 ** <li>[[SQLITE_FCNTL_TRACE]] 1068 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1069 ** to the VFS about what the higher layers of the SQLite stack are doing. 1070 ** This file control is used by some VFS activity tracing [shims]. 1071 ** The argument is a zero-terminated string. Higher layers in the 1072 ** SQLite stack may generate instances of this file control if 1073 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1074 ** 1075 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1076 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1077 ** pointer to an integer and it writes a boolean into that integer depending 1078 ** on whether or not the file has been renamed, moved, or deleted since it 1079 ** was first opened. 1080 ** 1081 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1082 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1083 ** underlying native file handle associated with a file handle. This file 1084 ** control interprets its argument as a pointer to a native file handle and 1085 ** writes the resulting value there. 1086 ** 1087 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1088 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1089 ** opcode causes the xFileControl method to swap the file handle with the one 1090 ** pointed to by the pArg argument. This capability is used during testing 1091 ** and only needs to be supported when SQLITE_TEST is defined. 1092 ** 1093 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1094 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1095 ** be advantageous to block on the next WAL lock if the lock is not immediately 1096 ** available. The WAL subsystem issues this signal during rare 1097 ** circumstances in order to fix a problem with priority inversion. 1098 ** Applications should <em>not</em> use this file-control. 1099 ** 1100 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1101 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1102 ** VFS should return SQLITE_NOTFOUND for this opcode. 1103 ** 1104 ** <li>[[SQLITE_FCNTL_RBU]] 1105 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1106 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1107 ** this opcode. 1108 ** 1109 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1110 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1111 ** the file descriptor is placed in "batch write mode", which 1112 ** means all subsequent write operations will be deferred and done 1113 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1114 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1115 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1116 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1117 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1118 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1119 ** except for calls to the xWrite method and the xFileControl method 1120 ** with [SQLITE_FCNTL_SIZE_HINT]. 1121 ** 1122 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1123 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1124 ** operations since the previous successful call to 1125 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1126 ** This file control returns [SQLITE_OK] if and only if the writes were 1127 ** all performed successfully and have been committed to persistent storage. 1128 ** ^Regardless of whether or not it is successful, this file control takes 1129 ** the file descriptor out of batch write mode so that all subsequent 1130 ** write operations are independent. 1131 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1132 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1133 ** 1134 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1135 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1136 ** operations since the previous successful call to 1137 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1138 ** ^This file control takes the file descriptor out of batch write mode 1139 ** so that all subsequent write operations are independent. 1140 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1141 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1142 ** 1143 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1144 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1145 ** to block for up to M milliseconds before failing when attempting to 1146 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1147 ** The parameter is a pointer to a 32-bit signed integer that contains 1148 ** the value that M is to be set to. Before returning, the 32-bit signed 1149 ** integer is overwritten with the previous value of M. 1150 ** 1151 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1152 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1153 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1154 ** The "data version" for the pager is written into the pointer. The 1155 ** "data version" changes whenever any change occurs to the corresponding 1156 ** database file, either through SQL statements on the same database 1157 ** connection or through transactions committed by separate database 1158 ** connections possibly in other processes. The [sqlite3_total_changes()] 1159 ** interface can be used to find if any database on the connection has changed, 1160 ** but that interface responds to changes on TEMP as well as MAIN and does 1161 ** not provide a mechanism to detect changes to MAIN only. Also, the 1162 ** [sqlite3_total_changes()] interface responds to internal changes only and 1163 ** omits changes made by other database connections. The 1164 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1165 ** a single attached database that occur due to other database connections, 1166 ** but omits changes implemented by the database connection on which it is 1167 ** called. This file control is the only mechanism to detect changes that 1168 ** happen either internally or externally and that are associated with 1169 ** a particular attached database. 1170 ** 1171 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1172 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1173 ** in wal mode before the client starts to copy pages from the wal 1174 ** file to the database file. 1175 ** 1176 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1177 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1178 ** in wal mode after the client has finished copying pages from the wal 1179 ** file to the database file, but before the *-shm file is updated to 1180 ** record the fact that the pages have been checkpointed. 1181 ** 1182 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1183 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1184 ** whether or not there is a database client in another process with a wal-mode 1185 ** transaction open on the database or not. It is only available on unix.The 1186 ** (void*) argument passed with this file-control should be a pointer to a 1187 ** value of type (int). The integer value is set to 1 if the database is a wal 1188 ** mode database and there exists at least one client in another process that 1189 ** currently has an SQL transaction open on the database. It is set to 0 if 1190 ** the database is not a wal-mode db, or if there is no such connection in any 1191 ** other process. This opcode cannot be used to detect transactions opened 1192 ** by clients within the current process, only within other processes. 1193 ** 1194 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1195 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the 1196 ** [checksum VFS shim] only. 1197 ** 1198 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1199 ** If there is currently no transaction open on the database, and the 1200 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control 1201 ** purges the contents of the in-memory page cache. If there is an open 1202 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error. 1203 ** </ul> 1204 */ 1205 #define SQLITE_FCNTL_LOCKSTATE 1 1206 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1207 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1208 #define SQLITE_FCNTL_LAST_ERRNO 4 1209 #define SQLITE_FCNTL_SIZE_HINT 5 1210 #define SQLITE_FCNTL_CHUNK_SIZE 6 1211 #define SQLITE_FCNTL_FILE_POINTER 7 1212 #define SQLITE_FCNTL_SYNC_OMITTED 8 1213 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1214 #define SQLITE_FCNTL_PERSIST_WAL 10 1215 #define SQLITE_FCNTL_OVERWRITE 11 1216 #define SQLITE_FCNTL_VFSNAME 12 1217 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1218 #define SQLITE_FCNTL_PRAGMA 14 1219 #define SQLITE_FCNTL_BUSYHANDLER 15 1220 #define SQLITE_FCNTL_TEMPFILENAME 16 1221 #define SQLITE_FCNTL_MMAP_SIZE 18 1222 #define SQLITE_FCNTL_TRACE 19 1223 #define SQLITE_FCNTL_HAS_MOVED 20 1224 #define SQLITE_FCNTL_SYNC 21 1225 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1226 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1227 #define SQLITE_FCNTL_WAL_BLOCK 24 1228 #define SQLITE_FCNTL_ZIPVFS 25 1229 #define SQLITE_FCNTL_RBU 26 1230 #define SQLITE_FCNTL_VFS_POINTER 27 1231 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1232 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1233 #define SQLITE_FCNTL_PDB 30 1234 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1235 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1236 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1237 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1238 #define SQLITE_FCNTL_DATA_VERSION 35 1239 #define SQLITE_FCNTL_SIZE_LIMIT 36 1240 #define SQLITE_FCNTL_CKPT_DONE 37 1241 #define SQLITE_FCNTL_RESERVE_BYTES 38 1242 #define SQLITE_FCNTL_CKPT_START 39 1243 #define SQLITE_FCNTL_EXTERNAL_READER 40 1244 #define SQLITE_FCNTL_CKSM_FILE 41 1245 #define SQLITE_FCNTL_RESET_CACHE 42 1246 1247 /* deprecated names */ 1248 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1249 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1250 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1251 1252 1253 /* 1254 ** CAPI3REF: Mutex Handle 1255 ** 1256 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1257 ** abstract type for a mutex object. The SQLite core never looks 1258 ** at the internal representation of an [sqlite3_mutex]. It only 1259 ** deals with pointers to the [sqlite3_mutex] object. 1260 ** 1261 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1262 */ 1263 typedef struct sqlite3_mutex sqlite3_mutex; 1264 1265 /* 1266 ** CAPI3REF: Loadable Extension Thunk 1267 ** 1268 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1269 ** the third parameter to entry points of [loadable extensions]. This 1270 ** structure must be typedefed in order to work around compiler warnings 1271 ** on some platforms. 1272 */ 1273 typedef struct sqlite3_api_routines sqlite3_api_routines; 1274 1275 /* 1276 ** CAPI3REF: File Name 1277 ** 1278 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1279 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1280 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1281 ** may also be passed to special APIs such as: 1282 ** 1283 ** <ul> 1284 ** <li> sqlite3_filename_database() 1285 ** <li> sqlite3_filename_journal() 1286 ** <li> sqlite3_filename_wal() 1287 ** <li> sqlite3_uri_parameter() 1288 ** <li> sqlite3_uri_boolean() 1289 ** <li> sqlite3_uri_int64() 1290 ** <li> sqlite3_uri_key() 1291 ** </ul> 1292 */ 1293 typedef const char *sqlite3_filename; 1294 1295 /* 1296 ** CAPI3REF: OS Interface Object 1297 ** 1298 ** An instance of the sqlite3_vfs object defines the interface between 1299 ** the SQLite core and the underlying operating system. The "vfs" 1300 ** in the name of the object stands for "virtual file system". See 1301 ** the [VFS | VFS documentation] for further information. 1302 ** 1303 ** The VFS interface is sometimes extended by adding new methods onto 1304 ** the end. Each time such an extension occurs, the iVersion field 1305 ** is incremented. The iVersion value started out as 1 in 1306 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1307 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1308 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1309 ** may be appended to the sqlite3_vfs object and the iVersion value 1310 ** may increase again in future versions of SQLite. 1311 ** Note that due to an oversight, the structure 1312 ** of the sqlite3_vfs object changed in the transition from 1313 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1314 ** and yet the iVersion field was not increased. 1315 ** 1316 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1317 ** structure used by this VFS. mxPathname is the maximum length of 1318 ** a pathname in this VFS. 1319 ** 1320 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1321 ** the pNext pointer. The [sqlite3_vfs_register()] 1322 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1323 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1324 ** searches the list. Neither the application code nor the VFS 1325 ** implementation should use the pNext pointer. 1326 ** 1327 ** The pNext field is the only field in the sqlite3_vfs 1328 ** structure that SQLite will ever modify. SQLite will only access 1329 ** or modify this field while holding a particular static mutex. 1330 ** The application should never modify anything within the sqlite3_vfs 1331 ** object once the object has been registered. 1332 ** 1333 ** The zName field holds the name of the VFS module. The name must 1334 ** be unique across all VFS modules. 1335 ** 1336 ** [[sqlite3_vfs.xOpen]] 1337 ** ^SQLite guarantees that the zFilename parameter to xOpen 1338 ** is either a NULL pointer or string obtained 1339 ** from xFullPathname() with an optional suffix added. 1340 ** ^If a suffix is added to the zFilename parameter, it will 1341 ** consist of a single "-" character followed by no more than 1342 ** 11 alphanumeric and/or "-" characters. 1343 ** ^SQLite further guarantees that 1344 ** the string will be valid and unchanged until xClose() is 1345 ** called. Because of the previous sentence, 1346 ** the [sqlite3_file] can safely store a pointer to the 1347 ** filename if it needs to remember the filename for some reason. 1348 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1349 ** must invent its own temporary name for the file. ^Whenever the 1350 ** xFilename parameter is NULL it will also be the case that the 1351 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1352 ** 1353 ** The flags argument to xOpen() includes all bits set in 1354 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1355 ** or [sqlite3_open16()] is used, then flags includes at least 1356 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1357 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1358 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1359 ** 1360 ** ^(SQLite will also add one of the following flags to the xOpen() 1361 ** call, depending on the object being opened: 1362 ** 1363 ** <ul> 1364 ** <li> [SQLITE_OPEN_MAIN_DB] 1365 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1366 ** <li> [SQLITE_OPEN_TEMP_DB] 1367 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1368 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1369 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1370 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1371 ** <li> [SQLITE_OPEN_WAL] 1372 ** </ul>)^ 1373 ** 1374 ** The file I/O implementation can use the object type flags to 1375 ** change the way it deals with files. For example, an application 1376 ** that does not care about crash recovery or rollback might make 1377 ** the open of a journal file a no-op. Writes to this journal would 1378 ** also be no-ops, and any attempt to read the journal would return 1379 ** SQLITE_IOERR. Or the implementation might recognize that a database 1380 ** file will be doing page-aligned sector reads and writes in a random 1381 ** order and set up its I/O subsystem accordingly. 1382 ** 1383 ** SQLite might also add one of the following flags to the xOpen method: 1384 ** 1385 ** <ul> 1386 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1387 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1388 ** </ul> 1389 ** 1390 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1391 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1392 ** will be set for TEMP databases and their journals, transient 1393 ** databases, and subjournals. 1394 ** 1395 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1396 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1397 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1398 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1399 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1400 ** be created, and that it is an error if it already exists. 1401 ** It is <i>not</i> used to indicate the file should be opened 1402 ** for exclusive access. 1403 ** 1404 ** ^At least szOsFile bytes of memory are allocated by SQLite 1405 ** to hold the [sqlite3_file] structure passed as the third 1406 ** argument to xOpen. The xOpen method does not have to 1407 ** allocate the structure; it should just fill it in. Note that 1408 ** the xOpen method must set the sqlite3_file.pMethods to either 1409 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1410 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1411 ** element will be valid after xOpen returns regardless of the success 1412 ** or failure of the xOpen call. 1413 ** 1414 ** [[sqlite3_vfs.xAccess]] 1415 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1416 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1417 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1418 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1419 ** flag is never actually used and is not implemented in the built-in 1420 ** VFSes of SQLite. The file is named by the second argument and can be a 1421 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1422 ** non-zero error code if there is an I/O error or if the name of 1423 ** the file given in the second argument is illegal. If SQLITE_OK 1424 ** is returned, then non-zero or zero is written into *pResOut to indicate 1425 ** whether or not the file is accessible. 1426 ** 1427 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1428 ** output buffer xFullPathname. The exact size of the output buffer 1429 ** is also passed as a parameter to both methods. If the output buffer 1430 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1431 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1432 ** to prevent this by setting mxPathname to a sufficiently large value. 1433 ** 1434 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1435 ** interfaces are not strictly a part of the filesystem, but they are 1436 ** included in the VFS structure for completeness. 1437 ** The xRandomness() function attempts to return nBytes bytes 1438 ** of good-quality randomness into zOut. The return value is 1439 ** the actual number of bytes of randomness obtained. 1440 ** The xSleep() method causes the calling thread to sleep for at 1441 ** least the number of microseconds given. ^The xCurrentTime() 1442 ** method returns a Julian Day Number for the current date and time as 1443 ** a floating point value. 1444 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1445 ** Day Number multiplied by 86400000 (the number of milliseconds in 1446 ** a 24-hour day). 1447 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1448 ** date and time if that method is available (if iVersion is 2 or 1449 ** greater and the function pointer is not NULL) and will fall back 1450 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1451 ** 1452 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1453 ** are not used by the SQLite core. These optional interfaces are provided 1454 ** by some VFSes to facilitate testing of the VFS code. By overriding 1455 ** system calls with functions under its control, a test program can 1456 ** simulate faults and error conditions that would otherwise be difficult 1457 ** or impossible to induce. The set of system calls that can be overridden 1458 ** varies from one VFS to another, and from one version of the same VFS to the 1459 ** next. Applications that use these interfaces must be prepared for any 1460 ** or all of these interfaces to be NULL or for their behavior to change 1461 ** from one release to the next. Applications must not attempt to access 1462 ** any of these methods if the iVersion of the VFS is less than 3. 1463 */ 1464 typedef struct sqlite3_vfs sqlite3_vfs; 1465 typedef void (*sqlite3_syscall_ptr)(void); 1466 struct sqlite3_vfs { 1467 int iVersion; /* Structure version number (currently 3) */ 1468 int szOsFile; /* Size of subclassed sqlite3_file */ 1469 int mxPathname; /* Maximum file pathname length */ 1470 sqlite3_vfs *pNext; /* Next registered VFS */ 1471 const char *zName; /* Name of this virtual file system */ 1472 void *pAppData; /* Pointer to application-specific data */ 1473 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1474 int flags, int *pOutFlags); 1475 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1476 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1477 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1478 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1479 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1480 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1481 void (*xDlClose)(sqlite3_vfs*, void*); 1482 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1483 int (*xSleep)(sqlite3_vfs*, int microseconds); 1484 int (*xCurrentTime)(sqlite3_vfs*, double*); 1485 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1486 /* 1487 ** The methods above are in version 1 of the sqlite_vfs object 1488 ** definition. Those that follow are added in version 2 or later 1489 */ 1490 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1491 /* 1492 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1493 ** Those below are for version 3 and greater. 1494 */ 1495 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1496 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1497 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1498 /* 1499 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1500 ** New fields may be appended in future versions. The iVersion 1501 ** value will increment whenever this happens. 1502 */ 1503 }; 1504 1505 /* 1506 ** CAPI3REF: Flags for the xAccess VFS method 1507 ** 1508 ** These integer constants can be used as the third parameter to 1509 ** the xAccess method of an [sqlite3_vfs] object. They determine 1510 ** what kind of permissions the xAccess method is looking for. 1511 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1512 ** simply checks whether the file exists. 1513 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1514 ** checks whether the named directory is both readable and writable 1515 ** (in other words, if files can be added, removed, and renamed within 1516 ** the directory). 1517 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1518 ** [temp_store_directory pragma], though this could change in a future 1519 ** release of SQLite. 1520 ** With SQLITE_ACCESS_READ, the xAccess method 1521 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1522 ** currently unused, though it might be used in a future release of 1523 ** SQLite. 1524 */ 1525 #define SQLITE_ACCESS_EXISTS 0 1526 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1527 #define SQLITE_ACCESS_READ 2 /* Unused */ 1528 1529 /* 1530 ** CAPI3REF: Flags for the xShmLock VFS method 1531 ** 1532 ** These integer constants define the various locking operations 1533 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1534 ** following are the only legal combinations of flags to the 1535 ** xShmLock method: 1536 ** 1537 ** <ul> 1538 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1539 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1540 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1541 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1542 ** </ul> 1543 ** 1544 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1545 ** was given on the corresponding lock. 1546 ** 1547 ** The xShmLock method can transition between unlocked and SHARED or 1548 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1549 ** and EXCLUSIVE. 1550 */ 1551 #define SQLITE_SHM_UNLOCK 1 1552 #define SQLITE_SHM_LOCK 2 1553 #define SQLITE_SHM_SHARED 4 1554 #define SQLITE_SHM_EXCLUSIVE 8 1555 1556 /* 1557 ** CAPI3REF: Maximum xShmLock index 1558 ** 1559 ** The xShmLock method on [sqlite3_io_methods] may use values 1560 ** between 0 and this upper bound as its "offset" argument. 1561 ** The SQLite core will never attempt to acquire or release a 1562 ** lock outside of this range 1563 */ 1564 #define SQLITE_SHM_NLOCK 8 1565 1566 1567 /* 1568 ** CAPI3REF: Initialize The SQLite Library 1569 ** 1570 ** ^The sqlite3_initialize() routine initializes the 1571 ** SQLite library. ^The sqlite3_shutdown() routine 1572 ** deallocates any resources that were allocated by sqlite3_initialize(). 1573 ** These routines are designed to aid in process initialization and 1574 ** shutdown on embedded systems. Workstation applications using 1575 ** SQLite normally do not need to invoke either of these routines. 1576 ** 1577 ** A call to sqlite3_initialize() is an "effective" call if it is 1578 ** the first time sqlite3_initialize() is invoked during the lifetime of 1579 ** the process, or if it is the first time sqlite3_initialize() is invoked 1580 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1581 ** of sqlite3_initialize() does any initialization. All other calls 1582 ** are harmless no-ops.)^ 1583 ** 1584 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1585 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1586 ** an effective call to sqlite3_shutdown() does any deinitialization. 1587 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1588 ** 1589 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1590 ** is not. The sqlite3_shutdown() interface must only be called from a 1591 ** single thread. All open [database connections] must be closed and all 1592 ** other SQLite resources must be deallocated prior to invoking 1593 ** sqlite3_shutdown(). 1594 ** 1595 ** Among other things, ^sqlite3_initialize() will invoke 1596 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1597 ** will invoke sqlite3_os_end(). 1598 ** 1599 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1600 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1601 ** the library (perhaps it is unable to allocate a needed resource such 1602 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1603 ** 1604 ** ^The sqlite3_initialize() routine is called internally by many other 1605 ** SQLite interfaces so that an application usually does not need to 1606 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1607 ** calls sqlite3_initialize() so the SQLite library will be automatically 1608 ** initialized when [sqlite3_open()] is called if it has not be initialized 1609 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1610 ** compile-time option, then the automatic calls to sqlite3_initialize() 1611 ** are omitted and the application must call sqlite3_initialize() directly 1612 ** prior to using any other SQLite interface. For maximum portability, 1613 ** it is recommended that applications always invoke sqlite3_initialize() 1614 ** directly prior to using any other SQLite interface. Future releases 1615 ** of SQLite may require this. In other words, the behavior exhibited 1616 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1617 ** default behavior in some future release of SQLite. 1618 ** 1619 ** The sqlite3_os_init() routine does operating-system specific 1620 ** initialization of the SQLite library. The sqlite3_os_end() 1621 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1622 ** performed by these routines include allocation or deallocation 1623 ** of static resources, initialization of global variables, 1624 ** setting up a default [sqlite3_vfs] module, or setting up 1625 ** a default configuration using [sqlite3_config()]. 1626 ** 1627 ** The application should never invoke either sqlite3_os_init() 1628 ** or sqlite3_os_end() directly. The application should only invoke 1629 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1630 ** interface is called automatically by sqlite3_initialize() and 1631 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1632 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1633 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1634 ** When [custom builds | built for other platforms] 1635 ** (using the [SQLITE_OS_OTHER=1] compile-time 1636 ** option) the application must supply a suitable implementation for 1637 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1638 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1639 ** must return [SQLITE_OK] on success and some other [error code] upon 1640 ** failure. 1641 */ 1642 SQLITE_API int sqlite3_initialize(void); 1643 SQLITE_API int sqlite3_shutdown(void); 1644 SQLITE_API int sqlite3_os_init(void); 1645 SQLITE_API int sqlite3_os_end(void); 1646 1647 /* 1648 ** CAPI3REF: Configuring The SQLite Library 1649 ** 1650 ** The sqlite3_config() interface is used to make global configuration 1651 ** changes to SQLite in order to tune SQLite to the specific needs of 1652 ** the application. The default configuration is recommended for most 1653 ** applications and so this routine is usually not necessary. It is 1654 ** provided to support rare applications with unusual needs. 1655 ** 1656 ** <b>The sqlite3_config() interface is not threadsafe. The application 1657 ** must ensure that no other SQLite interfaces are invoked by other 1658 ** threads while sqlite3_config() is running.</b> 1659 ** 1660 ** The first argument to sqlite3_config() is an integer 1661 ** [configuration option] that determines 1662 ** what property of SQLite is to be configured. Subsequent arguments 1663 ** vary depending on the [configuration option] 1664 ** in the first argument. 1665 ** 1666 ** For most configuration options, the sqlite3_config() interface 1667 ** may only be invoked prior to library initialization using 1668 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1669 ** The exceptional configuration options that may be invoked at any time 1670 ** are called "anytime configuration options". 1671 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1672 ** [sqlite3_shutdown()] with a first argument that is not an anytime 1673 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE. 1674 ** Note, however, that ^sqlite3_config() can be called as part of the 1675 ** implementation of an application-defined [sqlite3_os_init()]. 1676 ** 1677 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1678 ** ^If the option is unknown or SQLite is unable to set the option 1679 ** then this routine returns a non-zero [error code]. 1680 */ 1681 SQLITE_API int sqlite3_config(int, ...); 1682 1683 /* 1684 ** CAPI3REF: Configure database connections 1685 ** METHOD: sqlite3 1686 ** 1687 ** The sqlite3_db_config() interface is used to make configuration 1688 ** changes to a [database connection]. The interface is similar to 1689 ** [sqlite3_config()] except that the changes apply to a single 1690 ** [database connection] (specified in the first argument). 1691 ** 1692 ** The second argument to sqlite3_db_config(D,V,...) is the 1693 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1694 ** that indicates what aspect of the [database connection] is being configured. 1695 ** Subsequent arguments vary depending on the configuration verb. 1696 ** 1697 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1698 ** the call is considered successful. 1699 */ 1700 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1701 1702 /* 1703 ** CAPI3REF: Memory Allocation Routines 1704 ** 1705 ** An instance of this object defines the interface between SQLite 1706 ** and low-level memory allocation routines. 1707 ** 1708 ** This object is used in only one place in the SQLite interface. 1709 ** A pointer to an instance of this object is the argument to 1710 ** [sqlite3_config()] when the configuration option is 1711 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1712 ** By creating an instance of this object 1713 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1714 ** during configuration, an application can specify an alternative 1715 ** memory allocation subsystem for SQLite to use for all of its 1716 ** dynamic memory needs. 1717 ** 1718 ** Note that SQLite comes with several [built-in memory allocators] 1719 ** that are perfectly adequate for the overwhelming majority of applications 1720 ** and that this object is only useful to a tiny minority of applications 1721 ** with specialized memory allocation requirements. This object is 1722 ** also used during testing of SQLite in order to specify an alternative 1723 ** memory allocator that simulates memory out-of-memory conditions in 1724 ** order to verify that SQLite recovers gracefully from such 1725 ** conditions. 1726 ** 1727 ** The xMalloc, xRealloc, and xFree methods must work like the 1728 ** malloc(), realloc() and free() functions from the standard C library. 1729 ** ^SQLite guarantees that the second argument to 1730 ** xRealloc is always a value returned by a prior call to xRoundup. 1731 ** 1732 ** xSize should return the allocated size of a memory allocation 1733 ** previously obtained from xMalloc or xRealloc. The allocated size 1734 ** is always at least as big as the requested size but may be larger. 1735 ** 1736 ** The xRoundup method returns what would be the allocated size of 1737 ** a memory allocation given a particular requested size. Most memory 1738 ** allocators round up memory allocations at least to the next multiple 1739 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1740 ** Every memory allocation request coming in through [sqlite3_malloc()] 1741 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1742 ** that causes the corresponding memory allocation to fail. 1743 ** 1744 ** The xInit method initializes the memory allocator. For example, 1745 ** it might allocate any required mutexes or initialize internal data 1746 ** structures. The xShutdown method is invoked (indirectly) by 1747 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1748 ** by xInit. The pAppData pointer is used as the only parameter to 1749 ** xInit and xShutdown. 1750 ** 1751 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1752 ** the xInit method, so the xInit method need not be threadsafe. The 1753 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1754 ** not need to be threadsafe either. For all other methods, SQLite 1755 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1756 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1757 ** it is by default) and so the methods are automatically serialized. 1758 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1759 ** methods must be threadsafe or else make their own arrangements for 1760 ** serialization. 1761 ** 1762 ** SQLite will never invoke xInit() more than once without an intervening 1763 ** call to xShutdown(). 1764 */ 1765 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1766 struct sqlite3_mem_methods { 1767 void *(*xMalloc)(int); /* Memory allocation function */ 1768 void (*xFree)(void*); /* Free a prior allocation */ 1769 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1770 int (*xSize)(void*); /* Return the size of an allocation */ 1771 int (*xRoundup)(int); /* Round up request size to allocation size */ 1772 int (*xInit)(void*); /* Initialize the memory allocator */ 1773 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1774 void *pAppData; /* Argument to xInit() and xShutdown() */ 1775 }; 1776 1777 /* 1778 ** CAPI3REF: Configuration Options 1779 ** KEYWORDS: {configuration option} 1780 ** 1781 ** These constants are the available integer configuration options that 1782 ** can be passed as the first argument to the [sqlite3_config()] interface. 1783 ** 1784 ** Most of the configuration options for sqlite3_config() 1785 ** will only work if invoked prior to [sqlite3_initialize()] or after 1786 ** [sqlite3_shutdown()]. The few exceptions to this rule are called 1787 ** "anytime configuration options". 1788 ** ^Calling [sqlite3_config()] with a first argument that is not an 1789 ** anytime configuration option in between calls to [sqlite3_initialize()] and 1790 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE. 1791 ** 1792 ** The set of anytime configuration options can change (by insertions 1793 ** and/or deletions) from one release of SQLite to the next. 1794 ** As of SQLite version 3.42.0, the complete set of anytime configuration 1795 ** options is: 1796 ** <ul> 1797 ** <li> SQLITE_CONFIG_LOG 1798 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ 1799 ** </ul> 1800 ** 1801 ** New configuration options may be added in future releases of SQLite. 1802 ** Existing configuration options might be discontinued. Applications 1803 ** should check the return code from [sqlite3_config()] to make sure that 1804 ** the call worked. The [sqlite3_config()] interface will return a 1805 ** non-zero [error code] if a discontinued or unsupported configuration option 1806 ** is invoked. 1807 ** 1808 ** <dl> 1809 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1810 ** <dd>There are no arguments to this option. ^This option sets the 1811 ** [threading mode] to Single-thread. In other words, it disables 1812 ** all mutexing and puts SQLite into a mode where it can only be used 1813 ** by a single thread. ^If SQLite is compiled with 1814 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1815 ** it is not possible to change the [threading mode] from its default 1816 ** value of Single-thread and so [sqlite3_config()] will return 1817 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1818 ** configuration option.</dd> 1819 ** 1820 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1821 ** <dd>There are no arguments to this option. ^This option sets the 1822 ** [threading mode] to Multi-thread. In other words, it disables 1823 ** mutexing on [database connection] and [prepared statement] objects. 1824 ** The application is responsible for serializing access to 1825 ** [database connections] and [prepared statements]. But other mutexes 1826 ** are enabled so that SQLite will be safe to use in a multi-threaded 1827 ** environment as long as no two threads attempt to use the same 1828 ** [database connection] at the same time. ^If SQLite is compiled with 1829 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1830 ** it is not possible to set the Multi-thread [threading mode] and 1831 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1832 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1833 ** 1834 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1835 ** <dd>There are no arguments to this option. ^This option sets the 1836 ** [threading mode] to Serialized. In other words, this option enables 1837 ** all mutexes including the recursive 1838 ** mutexes on [database connection] and [prepared statement] objects. 1839 ** In this mode (which is the default when SQLite is compiled with 1840 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1841 ** to [database connections] and [prepared statements] so that the 1842 ** application is free to use the same [database connection] or the 1843 ** same [prepared statement] in different threads at the same time. 1844 ** ^If SQLite is compiled with 1845 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1846 ** it is not possible to set the Serialized [threading mode] and 1847 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1848 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1849 ** 1850 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1851 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1852 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1853 ** The argument specifies 1854 ** alternative low-level memory allocation routines to be used in place of 1855 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1856 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1857 ** before the [sqlite3_config()] call returns.</dd> 1858 ** 1859 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1860 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1861 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1862 ** The [sqlite3_mem_methods] 1863 ** structure is filled with the currently defined memory allocation routines.)^ 1864 ** This option can be used to overload the default memory allocation 1865 ** routines with a wrapper that simulations memory allocation failure or 1866 ** tracks memory usage, for example. </dd> 1867 ** 1868 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1869 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1870 ** type int, interpreted as a boolean, which if true provides a hint to 1871 ** SQLite that it should avoid large memory allocations if possible. 1872 ** SQLite will run faster if it is free to make large memory allocations, 1873 ** but some application might prefer to run slower in exchange for 1874 ** guarantees about memory fragmentation that are possible if large 1875 ** allocations are avoided. This hint is normally off. 1876 ** </dd> 1877 ** 1878 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1879 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1880 ** interpreted as a boolean, which enables or disables the collection of 1881 ** memory allocation statistics. ^(When memory allocation statistics are 1882 ** disabled, the following SQLite interfaces become non-operational: 1883 ** <ul> 1884 ** <li> [sqlite3_hard_heap_limit64()] 1885 ** <li> [sqlite3_memory_used()] 1886 ** <li> [sqlite3_memory_highwater()] 1887 ** <li> [sqlite3_soft_heap_limit64()] 1888 ** <li> [sqlite3_status64()] 1889 ** </ul>)^ 1890 ** ^Memory allocation statistics are enabled by default unless SQLite is 1891 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1892 ** allocation statistics are disabled by default. 1893 ** </dd> 1894 ** 1895 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1896 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1897 ** </dd> 1898 ** 1899 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1900 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1901 ** that SQLite can use for the database page cache with the default page 1902 ** cache implementation. 1903 ** This configuration option is a no-op if an application-defined page 1904 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1905 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1906 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1907 ** and the number of cache lines (N). 1908 ** The sz argument should be the size of the largest database page 1909 ** (a power of two between 512 and 65536) plus some extra bytes for each 1910 ** page header. ^The number of extra bytes needed by the page header 1911 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1912 ** ^It is harmless, apart from the wasted memory, 1913 ** for the sz parameter to be larger than necessary. The pMem 1914 ** argument must be either a NULL pointer or a pointer to an 8-byte 1915 ** aligned block of memory of at least sz*N bytes, otherwise 1916 ** subsequent behavior is undefined. 1917 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1918 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1919 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1920 ** is exhausted. 1921 ** ^If pMem is NULL and N is non-zero, then each database connection 1922 ** does an initial bulk allocation for page cache memory 1923 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1924 ** of -1024*N bytes if N is negative, . ^If additional 1925 ** page cache memory is needed beyond what is provided by the initial 1926 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1927 ** additional cache line. </dd> 1928 ** 1929 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1930 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1931 ** that SQLite will use for all of its dynamic memory allocation needs 1932 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1933 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1934 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1935 ** [SQLITE_ERROR] if invoked otherwise. 1936 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1937 ** An 8-byte aligned pointer to the memory, 1938 ** the number of bytes in the memory buffer, and the minimum allocation size. 1939 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1940 ** to using its default memory allocator (the system malloc() implementation), 1941 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1942 ** memory pointer is not NULL then the alternative memory 1943 ** allocator is engaged to handle all of SQLites memory allocation needs. 1944 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1945 ** boundary or subsequent behavior of SQLite will be undefined. 1946 ** The minimum allocation size is capped at 2**12. Reasonable values 1947 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1948 ** 1949 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1950 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1951 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1952 ** The argument specifies alternative low-level mutex routines to be used 1953 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1954 ** the content of the [sqlite3_mutex_methods] structure before the call to 1955 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1956 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1957 ** the entire mutexing subsystem is omitted from the build and hence calls to 1958 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1959 ** return [SQLITE_ERROR].</dd> 1960 ** 1961 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1962 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1963 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1964 ** [sqlite3_mutex_methods] 1965 ** structure is filled with the currently defined mutex routines.)^ 1966 ** This option can be used to overload the default mutex allocation 1967 ** routines with a wrapper used to track mutex usage for performance 1968 ** profiling or testing, for example. ^If SQLite is compiled with 1969 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1970 ** the entire mutexing subsystem is omitted from the build and hence calls to 1971 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1972 ** return [SQLITE_ERROR].</dd> 1973 ** 1974 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1975 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1976 ** the default size of lookaside memory on each [database connection]. 1977 ** The first argument is the 1978 ** size of each lookaside buffer slot and the second is the number of 1979 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1980 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1981 ** option to [sqlite3_db_config()] can be used to change the lookaside 1982 ** configuration on individual connections.)^ </dd> 1983 ** 1984 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1985 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1986 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1987 ** the interface to a custom page cache implementation.)^ 1988 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1989 ** 1990 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1991 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1992 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1993 ** the current page cache implementation into that object.)^ </dd> 1994 ** 1995 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1996 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1997 ** global [error log]. 1998 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1999 ** function with a call signature of void(*)(void*,int,const char*), 2000 ** and a pointer to void. ^If the function pointer is not NULL, it is 2001 ** invoked by [sqlite3_log()] to process each logging event. ^If the 2002 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 2003 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 2004 ** passed through as the first parameter to the application-defined logger 2005 ** function whenever that function is invoked. ^The second parameter to 2006 ** the logger function is a copy of the first parameter to the corresponding 2007 ** [sqlite3_log()] call and is intended to be a [result code] or an 2008 ** [extended result code]. ^The third parameter passed to the logger is 2009 ** log message after formatting via [sqlite3_snprintf()]. 2010 ** The SQLite logging interface is not reentrant; the logger function 2011 ** supplied by the application must not invoke any SQLite interface. 2012 ** In a multi-threaded application, the application-defined logger 2013 ** function must be threadsafe. </dd> 2014 ** 2015 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 2016 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 2017 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 2018 ** then URI handling is globally disabled.)^ ^If URI handling is globally 2019 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 2020 ** [sqlite3_open16()] or 2021 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2022 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2023 ** connection is opened. ^If it is globally disabled, filenames are 2024 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2025 ** database connection is opened. ^(By default, URI handling is globally 2026 ** disabled. The default value may be changed by compiling with the 2027 ** [SQLITE_USE_URI] symbol defined.)^ 2028 ** 2029 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2030 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2031 ** argument which is interpreted as a boolean in order to enable or disable 2032 ** the use of covering indices for full table scans in the query optimizer. 2033 ** ^The default setting is determined 2034 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2035 ** if that compile-time option is omitted. 2036 ** The ability to disable the use of covering indices for full table scans 2037 ** is because some incorrectly coded legacy applications might malfunction 2038 ** when the optimization is enabled. Providing the ability to 2039 ** disable the optimization allows the older, buggy application code to work 2040 ** without change even with newer versions of SQLite. 2041 ** 2042 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2043 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2044 ** <dd> These options are obsolete and should not be used by new code. 2045 ** They are retained for backwards compatibility but are now no-ops. 2046 ** </dd> 2047 ** 2048 ** [[SQLITE_CONFIG_SQLLOG]] 2049 ** <dt>SQLITE_CONFIG_SQLLOG 2050 ** <dd>This option is only available if sqlite is compiled with the 2051 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2052 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2053 ** The second should be of type (void*). The callback is invoked by the library 2054 ** in three separate circumstances, identified by the value passed as the 2055 ** fourth parameter. If the fourth parameter is 0, then the database connection 2056 ** passed as the second argument has just been opened. The third argument 2057 ** points to a buffer containing the name of the main database file. If the 2058 ** fourth parameter is 1, then the SQL statement that the third parameter 2059 ** points to has just been executed. Or, if the fourth parameter is 2, then 2060 ** the connection being passed as the second parameter is being closed. The 2061 ** third parameter is passed NULL In this case. An example of using this 2062 ** configuration option can be seen in the "test_sqllog.c" source file in 2063 ** the canonical SQLite source tree.</dd> 2064 ** 2065 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2066 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2067 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2068 ** that are the default mmap size limit (the default setting for 2069 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2070 ** ^The default setting can be overridden by each database connection using 2071 ** either the [PRAGMA mmap_size] command, or by using the 2072 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2073 ** will be silently truncated if necessary so that it does not exceed the 2074 ** compile-time maximum mmap size set by the 2075 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2076 ** ^If either argument to this option is negative, then that argument is 2077 ** changed to its compile-time default. 2078 ** 2079 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2080 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2081 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2082 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2083 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2084 ** that specifies the maximum size of the created heap. 2085 ** 2086 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2087 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2088 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2089 ** is a pointer to an integer and writes into that integer the number of extra 2090 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2091 ** The amount of extra space required can change depending on the compiler, 2092 ** target platform, and SQLite version. 2093 ** 2094 ** [[SQLITE_CONFIG_PMASZ]] 2095 ** <dt>SQLITE_CONFIG_PMASZ 2096 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2097 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2098 ** sorter to that integer. The default minimum PMA Size is set by the 2099 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2100 ** to help with sort operations when multithreaded sorting 2101 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2102 ** to be sorted exceeds the page size times the minimum of the 2103 ** [PRAGMA cache_size] setting and this value. 2104 ** 2105 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2106 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2107 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2108 ** becomes the [statement journal] spill-to-disk threshold. 2109 ** [Statement journals] are held in memory until their size (in bytes) 2110 ** exceeds this threshold, at which point they are written to disk. 2111 ** Or if the threshold is -1, statement journals are always held 2112 ** exclusively in memory. 2113 ** Since many statement journals never become large, setting the spill 2114 ** threshold to a value such as 64KiB can greatly reduce the amount of 2115 ** I/O required to support statement rollback. 2116 ** The default value for this setting is controlled by the 2117 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2118 ** 2119 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2120 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2121 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2122 ** of type (int) - the new value of the sorter-reference size threshold. 2123 ** Usually, when SQLite uses an external sort to order records according 2124 ** to an ORDER BY clause, all fields required by the caller are present in the 2125 ** sorted records. However, if SQLite determines based on the declared type 2126 ** of a table column that its values are likely to be very large - larger 2127 ** than the configured sorter-reference size threshold - then a reference 2128 ** is stored in each sorted record and the required column values loaded 2129 ** from the database as records are returned in sorted order. The default 2130 ** value for this option is to never use this optimization. Specifying a 2131 ** negative value for this option restores the default behavior. 2132 ** This option is only available if SQLite is compiled with the 2133 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2134 ** 2135 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2136 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2137 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2138 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2139 ** database created using [sqlite3_deserialize()]. This default maximum 2140 ** size can be adjusted up or down for individual databases using the 2141 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2142 ** configuration setting is never used, then the default maximum is determined 2143 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2144 ** compile-time option is not set, then the default maximum is 1073741824. 2145 ** 2146 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]] 2147 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW 2148 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability 2149 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is 2150 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability 2151 ** defaults to on. This configuration option queries the current setting or 2152 ** changes the setting to off or on. The argument is a pointer to an integer. 2153 ** If that integer initially holds a value of 1, then the ability for VIEWs to 2154 ** have ROWIDs is activated. If the integer initially holds zero, then the 2155 ** ability is deactivated. Any other initial value for the integer leaves the 2156 ** setting unchanged. After changes, if any, the integer is written with 2157 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite 2158 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and 2159 ** recommended case) then the integer is always filled with zero, regardless 2160 ** if its initial value. 2161 ** </dl> 2162 */ 2163 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2164 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2165 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2166 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2167 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2168 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2169 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2170 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2171 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2172 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2173 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2174 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2175 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2176 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2177 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2178 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2179 #define SQLITE_CONFIG_URI 17 /* int */ 2180 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2181 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2182 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2183 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2184 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2185 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2186 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2187 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2188 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2189 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2190 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2191 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2192 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */ 2193 #define SQLITE_CONFIG_CORRUPTION 40 /* xCorruption */ 2194 #define SQLITE_CONFIG_ENABLE_ICU 41 /* boolean */ 2195 2196 /* 2197 ** CAPI3REF: Database Connection Configuration Options 2198 ** 2199 ** These constants are the available integer configuration options that 2200 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2201 ** 2202 ** New configuration options may be added in future releases of SQLite. 2203 ** Existing configuration options might be discontinued. Applications 2204 ** should check the return code from [sqlite3_db_config()] to make sure that 2205 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2206 ** non-zero [error code] if a discontinued or unsupported configuration option 2207 ** is invoked. 2208 ** 2209 ** <dl> 2210 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2211 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2212 ** <dd> ^This option takes three additional arguments that determine the 2213 ** [lookaside memory allocator] configuration for the [database connection]. 2214 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2215 ** pointer to a memory buffer to use for lookaside memory. 2216 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2217 ** may be NULL in which case SQLite will allocate the 2218 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2219 ** size of each lookaside buffer slot. ^The third argument is the number of 2220 ** slots. The size of the buffer in the first argument must be greater than 2221 ** or equal to the product of the second and third arguments. The buffer 2222 ** must be aligned to an 8-byte boundary. ^If the second argument to 2223 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2224 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2225 ** configuration for a database connection can only be changed when that 2226 ** connection is not currently using lookaside memory, or in other words 2227 ** when the "current value" returned by 2228 ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero. 2229 ** Any attempt to change the lookaside memory configuration when lookaside 2230 ** memory is in use leaves the configuration unchanged and returns 2231 ** [SQLITE_BUSY].)^</dd> 2232 ** 2233 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2234 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2235 ** <dd> ^This option is used to enable or disable the enforcement of 2236 ** [foreign key constraints]. There should be two additional arguments. 2237 ** The first argument is an integer which is 0 to disable FK enforcement, 2238 ** positive to enable FK enforcement or negative to leave FK enforcement 2239 ** unchanged. The second parameter is a pointer to an integer into which 2240 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2241 ** following this call. The second parameter may be a NULL pointer, in 2242 ** which case the FK enforcement setting is not reported back. </dd> 2243 ** 2244 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2245 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2246 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2247 ** There should be two additional arguments. 2248 ** The first argument is an integer which is 0 to disable triggers, 2249 ** positive to enable triggers or negative to leave the setting unchanged. 2250 ** The second parameter is a pointer to an integer into which 2251 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2252 ** following this call. The second parameter may be a NULL pointer, in 2253 ** which case the trigger setting is not reported back. 2254 ** 2255 ** <p>Originally this option disabled all triggers. ^(However, since 2256 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2257 ** this option is off. So, in other words, this option now only disables 2258 ** triggers in the main database schema or in the schemas of ATTACH-ed 2259 ** databases.)^ </dd> 2260 ** 2261 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2262 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2263 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2264 ** There should be two additional arguments. 2265 ** The first argument is an integer which is 0 to disable views, 2266 ** positive to enable views or negative to leave the setting unchanged. 2267 ** The second parameter is a pointer to an integer into which 2268 ** is written 0 or 1 to indicate whether views are disabled or enabled 2269 ** following this call. The second parameter may be a NULL pointer, in 2270 ** which case the view setting is not reported back. 2271 ** 2272 ** <p>Originally this option disabled all views. ^(However, since 2273 ** SQLite version 3.35.0, TEMP views are still allowed even if 2274 ** this option is off. So, in other words, this option now only disables 2275 ** views in the main database schema or in the schemas of ATTACH-ed 2276 ** databases.)^ </dd> 2277 ** 2278 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2279 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2280 ** <dd> ^This option is used to enable or disable the 2281 ** [fts3_tokenizer()] function which is part of the 2282 ** [FTS3] full-text search engine extension. 2283 ** There should be two additional arguments. 2284 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2285 ** positive to enable fts3_tokenizer() or negative to leave the setting 2286 ** unchanged. 2287 ** The second parameter is a pointer to an integer into which 2288 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2289 ** following this call. The second parameter may be a NULL pointer, in 2290 ** which case the new setting is not reported back. </dd> 2291 ** 2292 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2293 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2294 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2295 ** interface independently of the [load_extension()] SQL function. 2296 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2297 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2298 ** There should be two additional arguments. 2299 ** When the first argument to this interface is 1, then only the C-API is 2300 ** enabled and the SQL function remains disabled. If the first argument to 2301 ** this interface is 0, then both the C-API and the SQL function are disabled. 2302 ** If the first argument is -1, then no changes are made to state of either the 2303 ** C-API or the SQL function. 2304 ** The second parameter is a pointer to an integer into which 2305 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2306 ** is disabled or enabled following this call. The second parameter may 2307 ** be a NULL pointer, in which case the new setting is not reported back. 2308 ** </dd> 2309 ** 2310 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2311 ** <dd> ^This option is used to change the name of the "main" database 2312 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2313 ** which will become the new schema name in place of "main". ^SQLite 2314 ** does not make a copy of the new main schema name string, so the application 2315 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2316 ** until after the database connection closes. 2317 ** </dd> 2318 ** 2319 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2320 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2321 ** <dd> Usually, when a database in wal mode is closed or detached from a 2322 ** database handle, SQLite checks if this will mean that there are now no 2323 ** connections at all to the database. If so, it performs a checkpoint 2324 ** operation before closing the connection. This option may be used to 2325 ** override this behavior. The first parameter passed to this operation 2326 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2327 ** default) to enable them, and negative to leave the setting unchanged. 2328 ** The second parameter is a pointer to an integer 2329 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2330 ** have been disabled - 0 if they are not disabled, 1 if they are. 2331 ** </dd> 2332 ** 2333 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2334 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2335 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2336 ** a single SQL query statement will always use the same algorithm regardless 2337 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2338 ** that look at the values of bound parameters, which can make some queries 2339 ** slower. But the QPSG has the advantage of more predictable behavior. With 2340 ** the QPSG active, SQLite will always use the same query plan in the field as 2341 ** was used during testing in the lab. 2342 ** The first argument to this setting is an integer which is 0 to disable 2343 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2344 ** unchanged. The second parameter is a pointer to an integer into which 2345 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2346 ** following this call. 2347 ** </dd> 2348 ** 2349 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2350 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2351 ** include output for any operations performed by trigger programs. This 2352 ** option is used to set or clear (the default) a flag that governs this 2353 ** behavior. The first parameter passed to this operation is an integer - 2354 ** positive to enable output for trigger programs, or zero to disable it, 2355 ** or negative to leave the setting unchanged. 2356 ** The second parameter is a pointer to an integer into which is written 2357 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2358 ** it is not disabled, 1 if it is. 2359 ** </dd> 2360 ** 2361 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2362 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2363 ** [VACUUM] in order to reset a database back to an empty database 2364 ** with no schema and no content. The following process works even for 2365 ** a badly corrupted database file: 2366 ** <ol> 2367 ** <li> If the database connection is newly opened, make sure it has read the 2368 ** database schema by preparing then discarding some query against the 2369 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2370 ** errors. This step is only necessary if the application desires to keep 2371 ** the database in WAL mode after the reset if it was in WAL mode before 2372 ** the reset. 2373 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2374 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2375 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2376 ** </ol> 2377 ** Because resetting a database is destructive and irreversible, the 2378 ** process requires the use of this obscure API and multiple steps to 2379 ** help ensure that it does not happen by accident. Because this 2380 ** feature must be capable of resetting corrupt databases, and 2381 ** shutting down virtual tables may require access to that corrupt 2382 ** storage, the library must abandon any installed virtual tables 2383 ** without calling their xDestroy() methods. 2384 ** 2385 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2386 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2387 ** "defensive" flag for a database connection. When the defensive 2388 ** flag is enabled, language features that allow ordinary SQL to 2389 ** deliberately corrupt the database file are disabled. The disabled 2390 ** features include but are not limited to the following: 2391 ** <ul> 2392 ** <li> The [PRAGMA writable_schema=ON] statement. 2393 ** <li> The [PRAGMA journal_mode=OFF] statement. 2394 ** <li> The [PRAGMA schema_version=N] statement. 2395 ** <li> Writes to the [sqlite_dbpage] virtual table. 2396 ** <li> Direct writes to [shadow tables]. 2397 ** </ul> 2398 ** </dd> 2399 ** 2400 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2401 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2402 ** "writable_schema" flag. This has the same effect and is logically equivalent 2403 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2404 ** The first argument to this setting is an integer which is 0 to disable 2405 ** the writable_schema, positive to enable writable_schema, or negative to 2406 ** leave the setting unchanged. The second parameter is a pointer to an 2407 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2408 ** is enabled or disabled following this call. 2409 ** </dd> 2410 ** 2411 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2412 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2413 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2414 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2415 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2416 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2417 ** additional information. This feature can also be turned on and off 2418 ** using the [PRAGMA legacy_alter_table] statement. 2419 ** </dd> 2420 ** 2421 ** [[SQLITE_DBCONFIG_DQS_DML]] 2422 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt> 2423 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2424 ** the legacy [double-quoted string literal] misfeature for DML statements 2425 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2426 ** default value of this setting is determined by the [-DSQLITE_DQS] 2427 ** compile-time option. 2428 ** </dd> 2429 ** 2430 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2431 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt> 2432 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2433 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2434 ** such as CREATE TABLE and CREATE INDEX. The 2435 ** default value of this setting is determined by the [-DSQLITE_DQS] 2436 ** compile-time option. 2437 ** </dd> 2438 ** 2439 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2440 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt> 2441 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2442 ** assume that database schemas are untainted by malicious content. 2443 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2444 ** takes additional defensive steps to protect the application from harm 2445 ** including: 2446 ** <ul> 2447 ** <li> Prohibit the use of SQL functions inside triggers, views, 2448 ** CHECK constraints, DEFAULT clauses, expression indexes, 2449 ** partial indexes, or generated columns 2450 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2451 ** <li> Prohibit the use of virtual tables inside of triggers or views 2452 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2453 ** </ul> 2454 ** This setting defaults to "on" for legacy compatibility, however 2455 ** all applications are advised to turn it off if possible. This setting 2456 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2457 ** </dd> 2458 ** 2459 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2460 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt> 2461 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2462 ** the legacy file format flag. When activated, this flag causes all newly 2463 ** created database file to have a schema format version number (the 4-byte 2464 ** integer found at offset 44 into the database header) of 1. This in turn 2465 ** means that the resulting database file will be readable and writable by 2466 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2467 ** newly created databases are generally not understandable by SQLite versions 2468 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2469 ** is now scarcely any need to generate database files that are compatible 2470 ** all the way back to version 3.0.0, and so this setting is of little 2471 ** practical use, but is provided so that SQLite can continue to claim the 2472 ** ability to generate new database files that are compatible with version 2473 ** 3.0.0. 2474 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2475 ** the [VACUUM] command will fail with an obscure error when attempting to 2476 ** process a table with generated columns and a descending index. This is 2477 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2478 ** either generated columns or descending indexes. 2479 ** </dd> 2480 ** 2481 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]] 2482 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt> 2483 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in 2484 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears 2485 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2() 2486 ** statistics. For statistics to be collected, the flag must be set on 2487 ** the database handle both when the SQL statement is prepared and when it 2488 ** is stepped. The flag is set (collection of statistics is enabled) 2489 ** by default. This option takes two arguments: an integer and a pointer to 2490 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or 2491 ** leave unchanged the statement scanstatus option. If the second argument 2492 ** is not NULL, then the value of the statement scanstatus setting after 2493 ** processing the first argument is written into the integer that the second 2494 ** argument points to. 2495 ** </dd> 2496 ** 2497 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]] 2498 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt> 2499 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order 2500 ** in which tables and indexes are scanned so that the scans start at the end 2501 ** and work toward the beginning rather than starting at the beginning and 2502 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the 2503 ** same as setting [PRAGMA reverse_unordered_selects]. This option takes 2504 ** two arguments which are an integer and a pointer to an integer. The first 2505 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the 2506 ** reverse scan order flag, respectively. If the second argument is not NULL, 2507 ** then 0 or 1 is written into the integer that the second argument points to 2508 ** depending on if the reverse scan order flag is set after processing the 2509 ** first argument. 2510 ** </dd> 2511 ** 2512 ** </dl> 2513 */ 2514 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2515 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2516 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2517 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2518 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2519 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2520 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2521 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2522 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2523 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2524 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2525 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2526 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2527 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2528 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2529 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2530 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2531 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2532 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */ 2533 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */ 2534 #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */ 2535 2536 /* 2537 ** CAPI3REF: Enable Or Disable Extended Result Codes 2538 ** METHOD: sqlite3 2539 ** 2540 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2541 ** [extended result codes] feature of SQLite. ^The extended result 2542 ** codes are disabled by default for historical compatibility. 2543 */ 2544 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2545 2546 /* 2547 ** CAPI3REF: Last Insert Rowid 2548 ** METHOD: sqlite3 2549 ** 2550 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2551 ** has a unique 64-bit signed 2552 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2553 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2554 ** names are not also used by explicitly declared columns. ^If 2555 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2556 ** is another alias for the rowid. 2557 ** 2558 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2559 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2560 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2561 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2562 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2563 ** zero. 2564 ** 2565 ** As well as being set automatically as rows are inserted into database 2566 ** tables, the value returned by this function may be set explicitly by 2567 ** [sqlite3_set_last_insert_rowid()] 2568 ** 2569 ** Some virtual table implementations may INSERT rows into rowid tables as 2570 ** part of committing a transaction (e.g. to flush data accumulated in memory 2571 ** to disk). In this case subsequent calls to this function return the rowid 2572 ** associated with these internal INSERT operations, which leads to 2573 ** unintuitive results. Virtual table implementations that do write to rowid 2574 ** tables in this way can avoid this problem by restoring the original 2575 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2576 ** control to the user. 2577 ** 2578 ** ^(If an [INSERT] occurs within a trigger then this routine will 2579 ** return the [rowid] of the inserted row as long as the trigger is 2580 ** running. Once the trigger program ends, the value returned 2581 ** by this routine reverts to what it was before the trigger was fired.)^ 2582 ** 2583 ** ^An [INSERT] that fails due to a constraint violation is not a 2584 ** successful [INSERT] and does not change the value returned by this 2585 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2586 ** and INSERT OR ABORT make no changes to the return value of this 2587 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2588 ** encounters a constraint violation, it does not fail. The 2589 ** INSERT continues to completion after deleting rows that caused 2590 ** the constraint problem so INSERT OR REPLACE will always change 2591 ** the return value of this interface.)^ 2592 ** 2593 ** ^For the purposes of this routine, an [INSERT] is considered to 2594 ** be successful even if it is subsequently rolled back. 2595 ** 2596 ** This function is accessible to SQL statements via the 2597 ** [last_insert_rowid() SQL function]. 2598 ** 2599 ** If a separate thread performs a new [INSERT] on the same 2600 ** database connection while the [sqlite3_last_insert_rowid()] 2601 ** function is running and thus changes the last insert [rowid], 2602 ** then the value returned by [sqlite3_last_insert_rowid()] is 2603 ** unpredictable and might not equal either the old or the new 2604 ** last insert [rowid]. 2605 */ 2606 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2607 2608 /* 2609 ** CAPI3REF: Set the Last Insert Rowid value. 2610 ** METHOD: sqlite3 2611 ** 2612 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2613 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2614 ** without inserting a row into the database. 2615 */ 2616 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2617 2618 /* 2619 ** CAPI3REF: Count The Number Of Rows Modified 2620 ** METHOD: sqlite3 2621 ** 2622 ** ^These functions return the number of rows modified, inserted or 2623 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2624 ** statement on the database connection specified by the only parameter. 2625 ** The two functions are identical except for the type of the return value 2626 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2627 ** or DELETE is greater than the maximum value supported by type "int", then 2628 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2629 ** type of SQL statement does not modify the value returned by these functions. 2630 ** 2631 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2632 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2633 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2634 ** 2635 ** Changes to a view that are intercepted by 2636 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2637 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2638 ** DELETE statement run on a view is always zero. Only changes made to real 2639 ** tables are counted. 2640 ** 2641 ** Things are more complicated if the sqlite3_changes() function is 2642 ** executed while a trigger program is running. This may happen if the 2643 ** program uses the [changes() SQL function], or if some other callback 2644 ** function invokes sqlite3_changes() directly. Essentially: 2645 ** 2646 ** <ul> 2647 ** <li> ^(Before entering a trigger program the value returned by 2648 ** sqlite3_changes() function is saved. After the trigger program 2649 ** has finished, the original value is restored.)^ 2650 ** 2651 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2652 ** statement sets the value returned by sqlite3_changes() 2653 ** upon completion as normal. Of course, this value will not include 2654 ** any changes performed by sub-triggers, as the sqlite3_changes() 2655 ** value will be saved and restored after each sub-trigger has run.)^ 2656 ** </ul> 2657 ** 2658 ** ^This means that if the changes() SQL function (or similar) is used 2659 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2660 ** returns the value as set when the calling statement began executing. 2661 ** ^If it is used by the second or subsequent such statement within a trigger 2662 ** program, the value returned reflects the number of rows modified by the 2663 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2664 ** 2665 ** If a separate thread makes changes on the same database connection 2666 ** while [sqlite3_changes()] is running then the value returned 2667 ** is unpredictable and not meaningful. 2668 ** 2669 ** See also: 2670 ** <ul> 2671 ** <li> the [sqlite3_total_changes()] interface 2672 ** <li> the [count_changes pragma] 2673 ** <li> the [changes() SQL function] 2674 ** <li> the [data_version pragma] 2675 ** </ul> 2676 */ 2677 SQLITE_API int sqlite3_changes(sqlite3*); 2678 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2679 2680 /* 2681 ** CAPI3REF: Total Number Of Rows Modified 2682 ** METHOD: sqlite3 2683 ** 2684 ** ^These functions return the total number of rows inserted, modified or 2685 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2686 ** since the database connection was opened, including those executed as 2687 ** part of trigger programs. The two functions are identical except for the 2688 ** type of the return value and that if the number of rows modified by the 2689 ** connection exceeds the maximum value supported by type "int", then 2690 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2691 ** any other type of SQL statement does not affect the value returned by 2692 ** sqlite3_total_changes(). 2693 ** 2694 ** ^Changes made as part of [foreign key actions] are included in the 2695 ** count, but those made as part of REPLACE constraint resolution are 2696 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2697 ** are not counted. 2698 ** 2699 ** The [sqlite3_total_changes(D)] interface only reports the number 2700 ** of rows that changed due to SQL statement run against database 2701 ** connection D. Any changes by other database connections are ignored. 2702 ** To detect changes against a database file from other database 2703 ** connections use the [PRAGMA data_version] command or the 2704 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2705 ** 2706 ** If a separate thread makes changes on the same database connection 2707 ** while [sqlite3_total_changes()] is running then the value 2708 ** returned is unpredictable and not meaningful. 2709 ** 2710 ** See also: 2711 ** <ul> 2712 ** <li> the [sqlite3_changes()] interface 2713 ** <li> the [count_changes pragma] 2714 ** <li> the [changes() SQL function] 2715 ** <li> the [data_version pragma] 2716 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2717 ** </ul> 2718 */ 2719 SQLITE_API int sqlite3_total_changes(sqlite3*); 2720 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2721 2722 /* 2723 ** CAPI3REF: Interrupt A Long-Running Query 2724 ** METHOD: sqlite3 2725 ** 2726 ** ^This function causes any pending database operation to abort and 2727 ** return at its earliest opportunity. This routine is typically 2728 ** called in response to a user action such as pressing "Cancel" 2729 ** or Ctrl-C where the user wants a long query operation to halt 2730 ** immediately. 2731 ** 2732 ** ^It is safe to call this routine from a thread different from the 2733 ** thread that is currently running the database operation. But it 2734 ** is not safe to call this routine with a [database connection] that 2735 ** is closed or might close before sqlite3_interrupt() returns. 2736 ** 2737 ** ^If an SQL operation is very nearly finished at the time when 2738 ** sqlite3_interrupt() is called, then it might not have an opportunity 2739 ** to be interrupted and might continue to completion. 2740 ** 2741 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2742 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2743 ** that is inside an explicit transaction, then the entire transaction 2744 ** will be rolled back automatically. 2745 ** 2746 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2747 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2748 ** that are started after the sqlite3_interrupt() call and before the 2749 ** running statement count reaches zero are interrupted as if they had been 2750 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2751 ** that are started after the running statement count reaches zero are 2752 ** not effected by the sqlite3_interrupt(). 2753 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2754 ** SQL statements is a no-op and has no effect on SQL statements 2755 ** that are started after the sqlite3_interrupt() call returns. 2756 ** 2757 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether 2758 ** or not an interrupt is currently in effect for [database connection] D. 2759 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise. 2760 */ 2761 SQLITE_API void sqlite3_interrupt(sqlite3*); 2762 SQLITE_API int sqlite3_is_interrupted(sqlite3*); 2763 2764 /* 2765 ** CAPI3REF: Determine If An SQL Statement Is Complete 2766 ** 2767 ** These routines are useful during command-line input to determine if the 2768 ** currently entered text seems to form a complete SQL statement or 2769 ** if additional input is needed before sending the text into 2770 ** SQLite for parsing. ^These routines return 1 if the input string 2771 ** appears to be a complete SQL statement. ^A statement is judged to be 2772 ** complete if it ends with a semicolon token and is not a prefix of a 2773 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2774 ** string literals or quoted identifier names or comments are not 2775 ** independent tokens (they are part of the token in which they are 2776 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2777 ** and comments that follow the final semicolon are ignored. 2778 ** 2779 ** ^These routines return 0 if the statement is incomplete. ^If a 2780 ** memory allocation fails, then SQLITE_NOMEM is returned. 2781 ** 2782 ** ^These routines do not parse the SQL statements thus 2783 ** will not detect syntactically incorrect SQL. 2784 ** 2785 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2786 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2787 ** automatically by sqlite3_complete16(). If that initialization fails, 2788 ** then the return value from sqlite3_complete16() will be non-zero 2789 ** regardless of whether or not the input SQL is complete.)^ 2790 ** 2791 ** The input to [sqlite3_complete()] must be a zero-terminated 2792 ** UTF-8 string. 2793 ** 2794 ** The input to [sqlite3_complete16()] must be a zero-terminated 2795 ** UTF-16 string in native byte order. 2796 */ 2797 SQLITE_API int sqlite3_complete(const char *sql); 2798 SQLITE_API int sqlite3_complete16(const void *sql); 2799 2800 /* 2801 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2802 ** KEYWORDS: {busy-handler callback} {busy handler} 2803 ** METHOD: sqlite3 2804 ** 2805 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2806 ** that might be invoked with argument P whenever 2807 ** an attempt is made to access a database table associated with 2808 ** [database connection] D when another thread 2809 ** or process has the table locked. 2810 ** The sqlite3_busy_handler() interface is used to implement 2811 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2812 ** 2813 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2814 ** is returned immediately upon encountering the lock. ^If the busy callback 2815 ** is not NULL, then the callback might be invoked with two arguments. 2816 ** 2817 ** ^The first argument to the busy handler is a copy of the void* pointer which 2818 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2819 ** the busy handler callback is the number of times that the busy handler has 2820 ** been invoked previously for the same locking event. ^If the 2821 ** busy callback returns 0, then no additional attempts are made to 2822 ** access the database and [SQLITE_BUSY] is returned 2823 ** to the application. 2824 ** ^If the callback returns non-zero, then another attempt 2825 ** is made to access the database and the cycle repeats. 2826 ** 2827 ** The presence of a busy handler does not guarantee that it will be invoked 2828 ** when there is lock contention. ^If SQLite determines that invoking the busy 2829 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2830 ** to the application instead of invoking the 2831 ** busy handler. 2832 ** Consider a scenario where one process is holding a read lock that 2833 ** it is trying to promote to a reserved lock and 2834 ** a second process is holding a reserved lock that it is trying 2835 ** to promote to an exclusive lock. The first process cannot proceed 2836 ** because it is blocked by the second and the second process cannot 2837 ** proceed because it is blocked by the first. If both processes 2838 ** invoke the busy handlers, neither will make any progress. Therefore, 2839 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2840 ** will induce the first process to release its read lock and allow 2841 ** the second process to proceed. 2842 ** 2843 ** ^The default busy callback is NULL. 2844 ** 2845 ** ^(There can only be a single busy handler defined for each 2846 ** [database connection]. Setting a new busy handler clears any 2847 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2848 ** or evaluating [PRAGMA busy_timeout=N] will change the 2849 ** busy handler and thus clear any previously set busy handler. 2850 ** 2851 ** The busy callback should not take any actions which modify the 2852 ** database connection that invoked the busy handler. In other words, 2853 ** the busy handler is not reentrant. Any such actions 2854 ** result in undefined behavior. 2855 ** 2856 ** A busy handler must not close the database connection 2857 ** or [prepared statement] that invoked the busy handler. 2858 */ 2859 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2860 2861 /* 2862 ** CAPI3REF: Set A Busy Timeout 2863 ** METHOD: sqlite3 2864 ** 2865 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2866 ** for a specified amount of time when a table is locked. ^The handler 2867 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2868 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2869 ** the handler returns 0 which causes [sqlite3_step()] to return 2870 ** [SQLITE_BUSY]. 2871 ** 2872 ** ^Calling this routine with an argument less than or equal to zero 2873 ** turns off all busy handlers. 2874 ** 2875 ** ^(There can only be a single busy handler for a particular 2876 ** [database connection] at any given moment. If another busy handler 2877 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2878 ** this routine, that other busy handler is cleared.)^ 2879 ** 2880 ** See also: [PRAGMA busy_timeout] 2881 */ 2882 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2883 2884 /* 2885 ** CAPI3REF: Convenience Routines For Running Queries 2886 ** METHOD: sqlite3 2887 ** 2888 ** This is a legacy interface that is preserved for backwards compatibility. 2889 ** Use of this interface is not recommended. 2890 ** 2891 ** Definition: A <b>result table</b> is memory data structure created by the 2892 ** [sqlite3_get_table()] interface. A result table records the 2893 ** complete query results from one or more queries. 2894 ** 2895 ** The table conceptually has a number of rows and columns. But 2896 ** these numbers are not part of the result table itself. These 2897 ** numbers are obtained separately. Let N be the number of rows 2898 ** and M be the number of columns. 2899 ** 2900 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2901 ** There are (N+1)*M elements in the array. The first M pointers point 2902 ** to zero-terminated strings that contain the names of the columns. 2903 ** The remaining entries all point to query results. NULL values result 2904 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2905 ** string representation as returned by [sqlite3_column_text()]. 2906 ** 2907 ** A result table might consist of one or more memory allocations. 2908 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2909 ** A result table should be deallocated using [sqlite3_free_table()]. 2910 ** 2911 ** ^(As an example of the result table format, suppose a query result 2912 ** is as follows: 2913 ** 2914 ** <blockquote><pre> 2915 ** Name | Age 2916 ** ----------------------- 2917 ** Alice | 43 2918 ** Bob | 28 2919 ** Cindy | 21 2920 ** </pre></blockquote> 2921 ** 2922 ** There are two columns (M==2) and three rows (N==3). Thus the 2923 ** result table has 8 entries. Suppose the result table is stored 2924 ** in an array named azResult. Then azResult holds this content: 2925 ** 2926 ** <blockquote><pre> 2927 ** azResult[0] = "Name"; 2928 ** azResult[1] = "Age"; 2929 ** azResult[2] = "Alice"; 2930 ** azResult[3] = "43"; 2931 ** azResult[4] = "Bob"; 2932 ** azResult[5] = "28"; 2933 ** azResult[6] = "Cindy"; 2934 ** azResult[7] = "21"; 2935 ** </pre></blockquote>)^ 2936 ** 2937 ** ^The sqlite3_get_table() function evaluates one or more 2938 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2939 ** string of its 2nd parameter and returns a result table to the 2940 ** pointer given in its 3rd parameter. 2941 ** 2942 ** After the application has finished with the result from sqlite3_get_table(), 2943 ** it must pass the result table pointer to sqlite3_free_table() in order to 2944 ** release the memory that was malloced. Because of the way the 2945 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2946 ** function must not try to call [sqlite3_free()] directly. Only 2947 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2948 ** 2949 ** The sqlite3_get_table() interface is implemented as a wrapper around 2950 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2951 ** to any internal data structures of SQLite. It uses only the public 2952 ** interface defined here. As a consequence, errors that occur in the 2953 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2954 ** reflected in subsequent calls to [sqlite3_errcode()] or 2955 ** [sqlite3_errmsg()]. 2956 */ 2957 SQLITE_API int sqlite3_get_table( 2958 sqlite3 *db, /* An open database */ 2959 const char *zSql, /* SQL to be evaluated */ 2960 char ***pazResult, /* Results of the query */ 2961 int *pnRow, /* Number of result rows written here */ 2962 int *pnColumn, /* Number of result columns written here */ 2963 char **pzErrmsg /* Error msg written here */ 2964 ); 2965 SQLITE_API void sqlite3_free_table(char **result); 2966 2967 /* 2968 ** CAPI3REF: Formatted String Printing Functions 2969 ** 2970 ** These routines are work-alikes of the "printf()" family of functions 2971 ** from the standard C library. 2972 ** These routines understand most of the common formatting options from 2973 ** the standard library printf() 2974 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2975 ** See the [built-in printf()] documentation for details. 2976 ** 2977 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2978 ** results into memory obtained from [sqlite3_malloc64()]. 2979 ** The strings returned by these two routines should be 2980 ** released by [sqlite3_free()]. ^Both routines return a 2981 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2982 ** memory to hold the resulting string. 2983 ** 2984 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2985 ** the standard C library. The result is written into the 2986 ** buffer supplied as the second parameter whose size is given by 2987 ** the first parameter. Note that the order of the 2988 ** first two parameters is reversed from snprintf().)^ This is an 2989 ** historical accident that cannot be fixed without breaking 2990 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2991 ** returns a pointer to its buffer instead of the number of 2992 ** characters actually written into the buffer.)^ We admit that 2993 ** the number of characters written would be a more useful return 2994 ** value but we cannot change the implementation of sqlite3_snprintf() 2995 ** now without breaking compatibility. 2996 ** 2997 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2998 ** guarantees that the buffer is always zero-terminated. ^The first 2999 ** parameter "n" is the total size of the buffer, including space for 3000 ** the zero terminator. So the longest string that can be completely 3001 ** written will be n-1 characters. 3002 ** 3003 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 3004 ** 3005 ** See also: [built-in printf()], [printf() SQL function] 3006 */ 3007 SQLITE_API char *sqlite3_mprintf(const char*,...); 3008 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 3009 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 3010 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 3011 3012 /* 3013 ** CAPI3REF: Memory Allocation Subsystem 3014 ** 3015 ** The SQLite core uses these three routines for all of its own 3016 ** internal memory allocation needs. "Core" in the previous sentence 3017 ** does not include operating-system specific [VFS] implementation. The 3018 ** Windows VFS uses native malloc() and free() for some operations. 3019 ** 3020 ** ^The sqlite3_malloc() routine returns a pointer to a block 3021 ** of memory at least N bytes in length, where N is the parameter. 3022 ** ^If sqlite3_malloc() is unable to obtain sufficient free 3023 ** memory, it returns a NULL pointer. ^If the parameter N to 3024 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 3025 ** a NULL pointer. 3026 ** 3027 ** ^The sqlite3_malloc64(N) routine works just like 3028 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 3029 ** of a signed 32-bit integer. 3030 ** 3031 ** ^Calling sqlite3_free() with a pointer previously returned 3032 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 3033 ** that it might be reused. ^The sqlite3_free() routine is 3034 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 3035 ** to sqlite3_free() is harmless. After being freed, memory 3036 ** should neither be read nor written. Even reading previously freed 3037 ** memory might result in a segmentation fault or other severe error. 3038 ** Memory corruption, a segmentation fault, or other severe error 3039 ** might result if sqlite3_free() is called with a non-NULL pointer that 3040 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 3041 ** 3042 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 3043 ** prior memory allocation X to be at least N bytes. 3044 ** ^If the X parameter to sqlite3_realloc(X,N) 3045 ** is a NULL pointer then its behavior is identical to calling 3046 ** sqlite3_malloc(N). 3047 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 3048 ** negative then the behavior is exactly the same as calling 3049 ** sqlite3_free(X). 3050 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 3051 ** of at least N bytes in size or NULL if insufficient memory is available. 3052 ** ^If M is the size of the prior allocation, then min(N,M) bytes 3053 ** of the prior allocation are copied into the beginning of buffer returned 3054 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 3055 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 3056 ** prior allocation is not freed. 3057 ** 3058 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 3059 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 3060 ** of a 32-bit signed integer. 3061 ** 3062 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 3063 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 3064 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 3065 ** ^The value returned by sqlite3_msize(X) might be larger than the number 3066 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3067 ** sqlite3_msize(X) returns zero. If X points to something that is not 3068 ** the beginning of memory allocation, or if it points to a formerly 3069 ** valid memory allocation that has now been freed, then the behavior 3070 ** of sqlite3_msize(X) is undefined and possibly harmful. 3071 ** 3072 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3073 ** sqlite3_malloc64(), and sqlite3_realloc64() 3074 ** is always aligned to at least an 8 byte boundary, or to a 3075 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3076 ** option is used. 3077 ** 3078 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3079 ** must be either NULL or else pointers obtained from a prior 3080 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3081 ** not yet been released. 3082 ** 3083 ** The application must not read or write any part of 3084 ** a block of memory after it has been released using 3085 ** [sqlite3_free()] or [sqlite3_realloc()]. 3086 */ 3087 SQLITE_API void *sqlite3_malloc(int); 3088 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3089 SQLITE_API void *sqlite3_realloc(void*, int); 3090 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3091 SQLITE_API void sqlite3_free(void*); 3092 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3093 3094 /* 3095 ** CAPI3REF: Memory Allocator Statistics 3096 ** 3097 ** SQLite provides these two interfaces for reporting on the status 3098 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3099 ** routines, which form the built-in memory allocation subsystem. 3100 ** 3101 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3102 ** of memory currently outstanding (malloced but not freed). 3103 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3104 ** value of [sqlite3_memory_used()] since the high-water mark 3105 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3106 ** [sqlite3_memory_highwater()] include any overhead 3107 ** added by SQLite in its implementation of [sqlite3_malloc()], 3108 ** but not overhead added by the any underlying system library 3109 ** routines that [sqlite3_malloc()] may call. 3110 ** 3111 ** ^The memory high-water mark is reset to the current value of 3112 ** [sqlite3_memory_used()] if and only if the parameter to 3113 ** [sqlite3_memory_highwater()] is true. ^The value returned 3114 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3115 ** prior to the reset. 3116 */ 3117 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3118 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3119 3120 /* 3121 ** CAPI3REF: Pseudo-Random Number Generator 3122 ** 3123 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3124 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3125 ** already uses the largest possible [ROWID]. The PRNG is also used for 3126 ** the built-in random() and randomblob() SQL functions. This interface allows 3127 ** applications to access the same PRNG for other purposes. 3128 ** 3129 ** ^A call to this routine stores N bytes of randomness into buffer P. 3130 ** ^The P parameter can be a NULL pointer. 3131 ** 3132 ** ^If this routine has not been previously called or if the previous 3133 ** call had N less than one or a NULL pointer for P, then the PRNG is 3134 ** seeded using randomness obtained from the xRandomness method of 3135 ** the default [sqlite3_vfs] object. 3136 ** ^If the previous call to this routine had an N of 1 or more and a 3137 ** non-NULL P then the pseudo-randomness is generated 3138 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3139 ** method. 3140 */ 3141 SQLITE_API void sqlite3_randomness(int N, void *P); 3142 3143 /* 3144 ** CAPI3REF: Compile-Time Authorization Callbacks 3145 ** METHOD: sqlite3 3146 ** KEYWORDS: {authorizer callback} 3147 ** 3148 ** ^This routine registers an authorizer callback with a particular 3149 ** [database connection], supplied in the first argument. 3150 ** ^The authorizer callback is invoked as SQL statements are being compiled 3151 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3152 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3153 ** and [sqlite3_prepare16_v3()]. ^At various 3154 ** points during the compilation process, as logic is being created 3155 ** to perform various actions, the authorizer callback is invoked to 3156 ** see if those actions are allowed. ^The authorizer callback should 3157 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3158 ** specific action but allow the SQL statement to continue to be 3159 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3160 ** rejected with an error. ^If the authorizer callback returns 3161 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3162 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3163 ** the authorizer will fail with an error message. 3164 ** 3165 ** When the callback returns [SQLITE_OK], that means the operation 3166 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3167 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3168 ** authorizer will fail with an error message explaining that 3169 ** access is denied. 3170 ** 3171 ** ^The first parameter to the authorizer callback is a copy of the third 3172 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3173 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3174 ** the particular action to be authorized. ^The third through sixth parameters 3175 ** to the callback are either NULL pointers or zero-terminated strings 3176 ** that contain additional details about the action to be authorized. 3177 ** Applications must always be prepared to encounter a NULL pointer in any 3178 ** of the third through the sixth parameters of the authorization callback. 3179 ** 3180 ** ^If the action code is [SQLITE_READ] 3181 ** and the callback returns [SQLITE_IGNORE] then the 3182 ** [prepared statement] statement is constructed to substitute 3183 ** a NULL value in place of the table column that would have 3184 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3185 ** return can be used to deny an untrusted user access to individual 3186 ** columns of a table. 3187 ** ^When a table is referenced by a [SELECT] but no column values are 3188 ** extracted from that table (for example in a query like 3189 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3190 ** is invoked once for that table with a column name that is an empty string. 3191 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3192 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3193 ** [truncate optimization] is disabled and all rows are deleted individually. 3194 ** 3195 ** An authorizer is used when [sqlite3_prepare | preparing] 3196 ** SQL statements from an untrusted source, to ensure that the SQL statements 3197 ** do not try to access data they are not allowed to see, or that they do not 3198 ** try to execute malicious statements that damage the database. For 3199 ** example, an application may allow a user to enter arbitrary 3200 ** SQL queries for evaluation by a database. But the application does 3201 ** not want the user to be able to make arbitrary changes to the 3202 ** database. An authorizer could then be put in place while the 3203 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3204 ** disallows everything except [SELECT] statements. 3205 ** 3206 ** Applications that need to process SQL from untrusted sources 3207 ** might also consider lowering resource limits using [sqlite3_limit()] 3208 ** and limiting database size using the [max_page_count] [PRAGMA] 3209 ** in addition to using an authorizer. 3210 ** 3211 ** ^(Only a single authorizer can be in place on a database connection 3212 ** at a time. Each call to sqlite3_set_authorizer overrides the 3213 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3214 ** The authorizer is disabled by default. 3215 ** 3216 ** The authorizer callback must not do anything that will modify 3217 ** the database connection that invoked the authorizer callback. 3218 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3219 ** database connections for the meaning of "modify" in this paragraph. 3220 ** 3221 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3222 ** statement might be re-prepared during [sqlite3_step()] due to a 3223 ** schema change. Hence, the application should ensure that the 3224 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3225 ** 3226 ** ^Note that the authorizer callback is invoked only during 3227 ** [sqlite3_prepare()] or its variants. Authorization is not 3228 ** performed during statement evaluation in [sqlite3_step()], unless 3229 ** as stated in the previous paragraph, sqlite3_step() invokes 3230 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3231 */ 3232 SQLITE_API int sqlite3_set_authorizer( 3233 sqlite3*, 3234 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3235 void *pUserData 3236 ); 3237 3238 #ifdef SQLITE_ENABLE_DROPTABLE_CALLBACK 3239 SQLITE_API int sqlite3_set_droptable_handle( 3240 sqlite3 *db, 3241 void (*xFunc)(sqlite3*,const char*,const char*) 3242 ); 3243 #endif 3244 3245 /* 3246 ** CAPI3REF: Authorizer Return Codes 3247 ** 3248 ** The [sqlite3_set_authorizer | authorizer callback function] must 3249 ** return either [SQLITE_OK] or one of these two constants in order 3250 ** to signal SQLite whether or not the action is permitted. See the 3251 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3252 ** information. 3253 ** 3254 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3255 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3256 */ 3257 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3258 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3259 3260 /* 3261 ** CAPI3REF: Authorizer Action Codes 3262 ** 3263 ** The [sqlite3_set_authorizer()] interface registers a callback function 3264 ** that is invoked to authorize certain SQL statement actions. The 3265 ** second parameter to the callback is an integer code that specifies 3266 ** what action is being authorized. These are the integer action codes that 3267 ** the authorizer callback may be passed. 3268 ** 3269 ** These action code values signify what kind of operation is to be 3270 ** authorized. The 3rd and 4th parameters to the authorization 3271 ** callback function will be parameters or NULL depending on which of these 3272 ** codes is used as the second parameter. ^(The 5th parameter to the 3273 ** authorizer callback is the name of the database ("main", "temp", 3274 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3275 ** is the name of the inner-most trigger or view that is responsible for 3276 ** the access attempt or NULL if this access attempt is directly from 3277 ** top-level SQL code. 3278 */ 3279 /******************************************* 3rd ************ 4th ***********/ 3280 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3281 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3282 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3283 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3284 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3285 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3286 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3287 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3288 #define SQLITE_DELETE 9 /* Table Name NULL */ 3289 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3290 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3291 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3292 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3293 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3294 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3295 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3296 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3297 #define SQLITE_INSERT 18 /* Table Name NULL */ 3298 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3299 #define SQLITE_READ 20 /* Table Name Column Name */ 3300 #define SQLITE_SELECT 21 /* NULL NULL */ 3301 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3302 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3303 #define SQLITE_ATTACH 24 /* Filename NULL */ 3304 #define SQLITE_DETACH 25 /* Database Name NULL */ 3305 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3306 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3307 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3308 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3309 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3310 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3311 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3312 #define SQLITE_COPY 0 /* No longer used */ 3313 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3314 3315 /* 3316 ** CAPI3REF: Tracing And Profiling Functions 3317 ** METHOD: sqlite3 3318 ** 3319 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3320 ** instead of the routines described here. 3321 ** 3322 ** These routines register callback functions that can be used for 3323 ** tracing and profiling the execution of SQL statements. 3324 ** 3325 ** ^The callback function registered by sqlite3_trace() is invoked at 3326 ** various times when an SQL statement is being run by [sqlite3_step()]. 3327 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3328 ** SQL statement text as the statement first begins executing. 3329 ** ^(Additional sqlite3_trace() callbacks might occur 3330 ** as each triggered subprogram is entered. The callbacks for triggers 3331 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3332 ** 3333 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3334 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3335 ** 3336 ** ^The callback function registered by sqlite3_profile() is invoked 3337 ** as each SQL statement finishes. ^The profile callback contains 3338 ** the original statement text and an estimate of wall-clock time 3339 ** of how long that statement took to run. ^The profile callback 3340 ** time is in units of nanoseconds, however the current implementation 3341 ** is only capable of millisecond resolution so the six least significant 3342 ** digits in the time are meaningless. Future versions of SQLite 3343 ** might provide greater resolution on the profiler callback. Invoking 3344 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3345 ** profile callback. 3346 */ 3347 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3348 void(*xTrace)(void*,const char*), void*); 3349 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3350 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3351 3352 /* 3353 ** CAPI3REF: SQL Trace Event Codes 3354 ** KEYWORDS: SQLITE_TRACE 3355 ** 3356 ** These constants identify classes of events that can be monitored 3357 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3358 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3359 ** the following constants. ^The first argument to the trace callback 3360 ** is one of the following constants. 3361 ** 3362 ** New tracing constants may be added in future releases. 3363 ** 3364 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3365 ** ^The T argument is one of the integer type codes above. 3366 ** ^The C argument is a copy of the context pointer passed in as the 3367 ** fourth argument to [sqlite3_trace_v2()]. 3368 ** The P and X arguments are pointers whose meanings depend on T. 3369 ** 3370 ** <dl> 3371 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3372 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3373 ** first begins running and possibly at other times during the 3374 ** execution of the prepared statement, such as at the start of each 3375 ** trigger subprogram. ^The P argument is a pointer to the 3376 ** [prepared statement]. ^The X argument is a pointer to a string which 3377 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3378 ** that indicates the invocation of a trigger. ^The callback can compute 3379 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3380 ** interface by using the X argument when X begins with "--" and invoking 3381 ** [sqlite3_expanded_sql(P)] otherwise. 3382 ** 3383 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3384 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3385 ** information as is provided by the [sqlite3_profile()] callback. 3386 ** ^The P argument is a pointer to the [prepared statement] and the 3387 ** X argument points to a 64-bit integer which is approximately 3388 ** the number of nanoseconds that the prepared statement took to run. 3389 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3390 ** 3391 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3392 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3393 ** statement generates a single row of result. 3394 ** ^The P argument is a pointer to the [prepared statement] and the 3395 ** X argument is unused. 3396 ** 3397 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3398 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3399 ** connection closes. 3400 ** ^The P argument is a pointer to the [database connection] object 3401 ** and the X argument is unused. 3402 ** </dl> 3403 */ 3404 #define SQLITE_TRACE_STMT 0x01 3405 #define SQLITE_TRACE_PROFILE 0x02 3406 #define SQLITE_TRACE_ROW 0x04 3407 #define SQLITE_TRACE_CLOSE 0x08 3408 3409 /* 3410 ** CAPI3REF: SQL Trace Hook 3411 ** METHOD: sqlite3 3412 ** 3413 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3414 ** function X against [database connection] D, using property mask M 3415 ** and context pointer P. ^If the X callback is 3416 ** NULL or if the M mask is zero, then tracing is disabled. The 3417 ** M argument should be the bitwise OR-ed combination of 3418 ** zero or more [SQLITE_TRACE] constants. 3419 ** 3420 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P) 3421 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or 3422 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each 3423 ** database connection may have at most one trace callback. 3424 ** 3425 ** ^The X callback is invoked whenever any of the events identified by 3426 ** mask M occur. ^The integer return value from the callback is currently 3427 ** ignored, though this may change in future releases. Callback 3428 ** implementations should return zero to ensure future compatibility. 3429 ** 3430 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3431 ** ^The T argument is one of the [SQLITE_TRACE] 3432 ** constants to indicate why the callback was invoked. 3433 ** ^The C argument is a copy of the context pointer. 3434 ** The P and X arguments are pointers whose meanings depend on T. 3435 ** 3436 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3437 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3438 ** are deprecated. 3439 */ 3440 SQLITE_API int sqlite3_trace_v2( 3441 sqlite3*, 3442 unsigned uMask, 3443 int(*xCallback)(unsigned,void*,void*,void*), 3444 void *pCtx 3445 ); 3446 3447 /* 3448 ** CAPI3REF: Query Progress Callbacks 3449 ** METHOD: sqlite3 3450 ** 3451 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3452 ** function X to be invoked periodically during long running calls to 3453 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for 3454 ** database connection D. An example use for this 3455 ** interface is to keep a GUI updated during a large query. 3456 ** 3457 ** ^The parameter P is passed through as the only parameter to the 3458 ** callback function X. ^The parameter N is the approximate number of 3459 ** [virtual machine instructions] that are evaluated between successive 3460 ** invocations of the callback X. ^If N is less than one then the progress 3461 ** handler is disabled. 3462 ** 3463 ** ^Only a single progress handler may be defined at one time per 3464 ** [database connection]; setting a new progress handler cancels the 3465 ** old one. ^Setting parameter X to NULL disables the progress handler. 3466 ** ^The progress handler is also disabled by setting N to a value less 3467 ** than 1. 3468 ** 3469 ** ^If the progress callback returns non-zero, the operation is 3470 ** interrupted. This feature can be used to implement a 3471 ** "Cancel" button on a GUI progress dialog box. 3472 ** 3473 ** The progress handler callback must not do anything that will modify 3474 ** the database connection that invoked the progress handler. 3475 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3476 ** database connections for the meaning of "modify" in this paragraph. 3477 ** 3478 ** The progress handler callback would originally only be invoked from the 3479 ** bytecode engine. It still might be invoked during [sqlite3_prepare()] 3480 ** and similar because those routines might force a reparse of the schema 3481 ** which involves running the bytecode engine. However, beginning with 3482 ** SQLite version 3.41.0, the progress handler callback might also be 3483 ** invoked directly from [sqlite3_prepare()] while analyzing and generating 3484 ** code for complex queries. 3485 */ 3486 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3487 3488 /* 3489 ** CAPI3REF: Opening A New Database Connection 3490 ** CONSTRUCTOR: sqlite3 3491 ** 3492 ** ^These routines open an SQLite database file as specified by the 3493 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3494 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3495 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3496 ** returned in *ppDb, even if an error occurs. The only exception is that 3497 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3498 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3499 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3500 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3501 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3502 ** an English language description of the error following a failure of any 3503 ** of the sqlite3_open() routines. 3504 ** 3505 ** ^The default encoding will be UTF-8 for databases created using 3506 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3507 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3508 ** 3509 ** Whether or not an error occurs when it is opened, resources 3510 ** associated with the [database connection] handle should be released by 3511 ** passing it to [sqlite3_close()] when it is no longer required. 3512 ** 3513 ** The sqlite3_open_v2() interface works like sqlite3_open() 3514 ** except that it accepts two additional parameters for additional control 3515 ** over the new database connection. ^(The flags parameter to 3516 ** sqlite3_open_v2() must include, at a minimum, one of the following 3517 ** three flag combinations:)^ 3518 ** 3519 ** <dl> 3520 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3521 ** <dd>The database is opened in read-only mode. If the database does 3522 ** not already exist, an error is returned.</dd>)^ 3523 ** 3524 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3525 ** <dd>The database is opened for reading and writing if possible, or 3526 ** reading only if the file is write protected by the operating 3527 ** system. In either case the database must already exist, otherwise 3528 ** an error is returned. For historical reasons, if opening in 3529 ** read-write mode fails due to OS-level permissions, an attempt is 3530 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be 3531 ** used to determine whether the database is actually 3532 ** read-write.</dd>)^ 3533 ** 3534 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3535 ** <dd>The database is opened for reading and writing, and is created if 3536 ** it does not already exist. This is the behavior that is always used for 3537 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3538 ** </dl> 3539 ** 3540 ** In addition to the required flags, the following optional flags are 3541 ** also supported: 3542 ** 3543 ** <dl> 3544 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3545 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3546 ** 3547 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3548 ** <dd>The database will be opened as an in-memory database. The database 3549 ** is named by the "filename" argument for the purposes of cache-sharing, 3550 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3551 ** </dd>)^ 3552 ** 3553 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3554 ** <dd>The new database connection will use the "multi-thread" 3555 ** [threading mode].)^ This means that separate threads are allowed 3556 ** to use SQLite at the same time, as long as each thread is using 3557 ** a different [database connection]. 3558 ** 3559 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3560 ** <dd>The new database connection will use the "serialized" 3561 ** [threading mode].)^ This means the multiple threads can safely 3562 ** attempt to use the same database connection at the same time. 3563 ** (Mutexes will block any actual concurrency, but in this mode 3564 ** there is no harm in trying.) 3565 ** 3566 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3567 ** <dd>The database is opened [shared cache] enabled, overriding 3568 ** the default shared cache setting provided by 3569 ** [sqlite3_enable_shared_cache()].)^ 3570 ** The [use of shared cache mode is discouraged] and hence shared cache 3571 ** capabilities may be omitted from many builds of SQLite. In such cases, 3572 ** this option is a no-op. 3573 ** 3574 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3575 ** <dd>The database is opened [shared cache] disabled, overriding 3576 ** the default shared cache setting provided by 3577 ** [sqlite3_enable_shared_cache()].)^ 3578 ** 3579 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3580 ** <dd>The database connection comes up in "extended result code mode". 3581 ** In other words, the database behaves has if 3582 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3583 ** connection as soon as the connection is created. In addition to setting 3584 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3585 ** to return an extended result code.</dd> 3586 ** 3587 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3588 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3589 ** </dl>)^ 3590 ** 3591 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3592 ** required combinations shown above optionally combined with other 3593 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3594 ** then the behavior is undefined. Historic versions of SQLite 3595 ** have silently ignored surplus bits in the flags parameter to 3596 ** sqlite3_open_v2(), however that behavior might not be carried through 3597 ** into future versions of SQLite and so applications should not rely 3598 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3599 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3600 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3601 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3602 ** by sqlite3_open_v2(). 3603 ** 3604 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3605 ** [sqlite3_vfs] object that defines the operating system interface that 3606 ** the new database connection should use. ^If the fourth parameter is 3607 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3608 ** 3609 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3610 ** is created for the connection. ^This in-memory database will vanish when 3611 ** the database connection is closed. Future versions of SQLite might 3612 ** make use of additional special filenames that begin with the ":" character. 3613 ** It is recommended that when a database filename actually does begin with 3614 ** a ":" character you should prefix the filename with a pathname such as 3615 ** "./" to avoid ambiguity. 3616 ** 3617 ** ^If the filename is an empty string, then a private, temporary 3618 ** on-disk database will be created. ^This private database will be 3619 ** automatically deleted as soon as the database connection is closed. 3620 ** 3621 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3622 ** 3623 ** ^If [URI filename] interpretation is enabled, and the filename argument 3624 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3625 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3626 ** set in the third argument to sqlite3_open_v2(), or if it has 3627 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3628 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3629 ** URI filename interpretation is turned off 3630 ** by default, but future releases of SQLite might enable URI filename 3631 ** interpretation by default. See "[URI filenames]" for additional 3632 ** information. 3633 ** 3634 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3635 ** authority, then it must be either an empty string or the string 3636 ** "localhost". ^If the authority is not an empty string or "localhost", an 3637 ** error is returned to the caller. ^The fragment component of a URI, if 3638 ** present, is ignored. 3639 ** 3640 ** ^SQLite uses the path component of the URI as the name of the disk file 3641 ** which contains the database. ^If the path begins with a '/' character, 3642 ** then it is interpreted as an absolute path. ^If the path does not begin 3643 ** with a '/' (meaning that the authority section is omitted from the URI) 3644 ** then the path is interpreted as a relative path. 3645 ** ^(On windows, the first component of an absolute path 3646 ** is a drive specification (e.g. "C:").)^ 3647 ** 3648 ** [[core URI query parameters]] 3649 ** The query component of a URI may contain parameters that are interpreted 3650 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3651 ** SQLite and its built-in [VFSes] interpret the 3652 ** following query parameters: 3653 ** 3654 ** <ul> 3655 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3656 ** a VFS object that provides the operating system interface that should 3657 ** be used to access the database file on disk. ^If this option is set to 3658 ** an empty string the default VFS object is used. ^Specifying an unknown 3659 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3660 ** present, then the VFS specified by the option takes precedence over 3661 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3662 ** 3663 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3664 ** "rwc", or "memory". Attempting to set it to any other value is 3665 ** an error)^. 3666 ** ^If "ro" is specified, then the database is opened for read-only 3667 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3668 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3669 ** "rw", then the database is opened for read-write (but not create) 3670 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3671 ** been set. ^Value "rwc" is equivalent to setting both 3672 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3673 ** set to "memory" then a pure [in-memory database] that never reads 3674 ** or writes from disk is used. ^It is an error to specify a value for 3675 ** the mode parameter that is less restrictive than that specified by 3676 ** the flags passed in the third parameter to sqlite3_open_v2(). 3677 ** 3678 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3679 ** "private". ^Setting it to "shared" is equivalent to setting the 3680 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3681 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3682 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3683 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3684 ** a URI filename, its value overrides any behavior requested by setting 3685 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3686 ** 3687 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3688 ** [powersafe overwrite] property does or does not apply to the 3689 ** storage media on which the database file resides. 3690 ** 3691 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3692 ** which if set disables file locking in rollback journal modes. This 3693 ** is useful for accessing a database on a filesystem that does not 3694 ** support locking. Caution: Database corruption might result if two 3695 ** or more processes write to the same database and any one of those 3696 ** processes uses nolock=1. 3697 ** 3698 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3699 ** parameter that indicates that the database file is stored on 3700 ** read-only media. ^When immutable is set, SQLite assumes that the 3701 ** database file cannot be changed, even by a process with higher 3702 ** privilege, and so the database is opened read-only and all locking 3703 ** and change detection is disabled. Caution: Setting the immutable 3704 ** property on a database file that does in fact change can result 3705 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3706 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3707 ** 3708 ** </ul> 3709 ** 3710 ** ^Specifying an unknown parameter in the query component of a URI is not an 3711 ** error. Future versions of SQLite might understand additional query 3712 ** parameters. See "[query parameters with special meaning to SQLite]" for 3713 ** additional information. 3714 ** 3715 ** [[URI filename examples]] <h3>URI filename examples</h3> 3716 ** 3717 ** <table border="1" align=center cellpadding=5> 3718 ** <tr><th> URI filenames <th> Results 3719 ** <tr><td> file:data.db <td> 3720 ** Open the file "data.db" in the current directory. 3721 ** <tr><td> file:/home/fred/data.db<br> 3722 ** file:///home/fred/data.db <br> 3723 ** file://localhost/home/fred/data.db <br> <td> 3724 ** Open the database file "/home/fred/data.db". 3725 ** <tr><td> file://darkstar/home/fred/data.db <td> 3726 ** An error. "darkstar" is not a recognized authority. 3727 ** <tr><td style="white-space:nowrap"> 3728 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3729 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3730 ** C:. Note that the %20 escaping in this example is not strictly 3731 ** necessary - space characters can be used literally 3732 ** in URI filenames. 3733 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3734 ** Open file "data.db" in the current directory for read-only access. 3735 ** Regardless of whether or not shared-cache mode is enabled by 3736 ** default, use a private cache. 3737 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3738 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3739 ** that uses dot-files in place of posix advisory locking. 3740 ** <tr><td> file:data.db?mode=readonly <td> 3741 ** An error. "readonly" is not a valid option for the "mode" parameter. 3742 ** Use "ro" instead: "file:data.db?mode=ro". 3743 ** </table> 3744 ** 3745 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3746 ** query components of a URI. A hexadecimal escape sequence consists of a 3747 ** percent sign - "%" - followed by exactly two hexadecimal digits 3748 ** specifying an octet value. ^Before the path or query components of a 3749 ** URI filename are interpreted, they are encoded using UTF-8 and all 3750 ** hexadecimal escape sequences replaced by a single byte containing the 3751 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3752 ** the results are undefined. 3753 ** 3754 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3755 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3756 ** codepage is currently defined. Filenames containing international 3757 ** characters must be converted to UTF-8 prior to passing them into 3758 ** sqlite3_open() or sqlite3_open_v2(). 3759 ** 3760 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3761 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3762 ** features that require the use of temporary files may fail. 3763 ** 3764 ** See also: [sqlite3_temp_directory] 3765 */ 3766 SQLITE_API int sqlite3_open( 3767 const char *filename, /* Database filename (UTF-8) */ 3768 sqlite3 **ppDb /* OUT: SQLite db handle */ 3769 ); 3770 SQLITE_API int sqlite3_open16( 3771 const void *filename, /* Database filename (UTF-16) */ 3772 sqlite3 **ppDb /* OUT: SQLite db handle */ 3773 ); 3774 SQLITE_API int sqlite3_open_v2( 3775 const char *filename, /* Database filename (UTF-8) */ 3776 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3777 int flags, /* Flags */ 3778 const char *zVfs /* Name of VFS module to use */ 3779 ); 3780 3781 /* 3782 ** CAPI3REF: Obtain Values For URI Parameters 3783 ** 3784 ** These are utility routines, useful to [VFS|custom VFS implementations], 3785 ** that check if a database file was a URI that contained a specific query 3786 ** parameter, and if so obtains the value of that query parameter. 3787 ** 3788 ** The first parameter to these interfaces (hereafter referred to 3789 ** as F) must be one of: 3790 ** <ul> 3791 ** <li> A database filename pointer created by the SQLite core and 3792 ** passed into the xOpen() method of a VFS implementation, or 3793 ** <li> A filename obtained from [sqlite3_db_filename()], or 3794 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3795 ** </ul> 3796 ** If the F parameter is not one of the above, then the behavior is 3797 ** undefined and probably undesirable. Older versions of SQLite were 3798 ** more tolerant of invalid F parameters than newer versions. 3799 ** 3800 ** If F is a suitable filename (as described in the previous paragraph) 3801 ** and if P is the name of the query parameter, then 3802 ** sqlite3_uri_parameter(F,P) returns the value of the P 3803 ** parameter if it exists or a NULL pointer if P does not appear as a 3804 ** query parameter on F. If P is a query parameter of F and it 3805 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3806 ** a pointer to an empty string. 3807 ** 3808 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3809 ** parameter and returns true (1) or false (0) according to the value 3810 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3811 ** value of query parameter P is one of "yes", "true", or "on" in any 3812 ** case or if the value begins with a non-zero number. The 3813 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3814 ** query parameter P is one of "no", "false", or "off" in any case or 3815 ** if the value begins with a numeric zero. If P is not a query 3816 ** parameter on F or if the value of P does not match any of the 3817 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3818 ** 3819 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3820 ** 64-bit signed integer and returns that integer, or D if P does not 3821 ** exist. If the value of P is something other than an integer, then 3822 ** zero is returned. 3823 ** 3824 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3825 ** the value) of the N-th query parameter for filename F, or a NULL 3826 ** pointer if N is less than zero or greater than the number of query 3827 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3828 ** the name of the first query parameter, 1 for the second parameter, and 3829 ** so forth. 3830 ** 3831 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3832 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3833 ** is not a database file pathname pointer that the SQLite core passed 3834 ** into the xOpen VFS method, then the behavior of this routine is undefined 3835 ** and probably undesirable. 3836 ** 3837 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3838 ** parameter can also be the name of a rollback journal file or WAL file 3839 ** in addition to the main database file. Prior to version 3.31.0, these 3840 ** routines would only work if F was the name of the main database file. 3841 ** When the F parameter is the name of the rollback journal or WAL file, 3842 ** it has access to all the same query parameters as were found on the 3843 ** main database file. 3844 ** 3845 ** See the [URI filename] documentation for additional information. 3846 */ 3847 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3848 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3849 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3850 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3851 3852 /* 3853 ** CAPI3REF: Translate filenames 3854 ** 3855 ** These routines are available to [VFS|custom VFS implementations] for 3856 ** translating filenames between the main database file, the journal file, 3857 ** and the WAL file. 3858 ** 3859 ** If F is the name of an sqlite database file, journal file, or WAL file 3860 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3861 ** returns the name of the corresponding database file. 3862 ** 3863 ** If F is the name of an sqlite database file, journal file, or WAL file 3864 ** passed by the SQLite core into the VFS, or if F is a database filename 3865 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3866 ** returns the name of the corresponding rollback journal file. 3867 ** 3868 ** If F is the name of an sqlite database file, journal file, or WAL file 3869 ** that was passed by the SQLite core into the VFS, or if F is a database 3870 ** filename obtained from [sqlite3_db_filename()], then 3871 ** sqlite3_filename_wal(F) returns the name of the corresponding 3872 ** WAL file. 3873 ** 3874 ** In all of the above, if F is not the name of a database, journal or WAL 3875 ** filename passed into the VFS from the SQLite core and F is not the 3876 ** return value from [sqlite3_db_filename()], then the result is 3877 ** undefined and is likely a memory access violation. 3878 */ 3879 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3880 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3881 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3882 3883 /* 3884 ** CAPI3REF: Database File Corresponding To A Journal 3885 ** 3886 ** ^If X is the name of a rollback or WAL-mode journal file that is 3887 ** passed into the xOpen method of [sqlite3_vfs], then 3888 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3889 ** object that represents the main database file. 3890 ** 3891 ** This routine is intended for use in custom [VFS] implementations 3892 ** only. It is not a general-purpose interface. 3893 ** The argument sqlite3_file_object(X) must be a filename pointer that 3894 ** has been passed into [sqlite3_vfs].xOpen method where the 3895 ** flags parameter to xOpen contains one of the bits 3896 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3897 ** of this routine results in undefined and probably undesirable 3898 ** behavior. 3899 */ 3900 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3901 3902 /* 3903 ** CAPI3REF: Create and Destroy VFS Filenames 3904 ** 3905 ** These interfaces are provided for use by [VFS shim] implementations and 3906 ** are not useful outside of that context. 3907 ** 3908 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3909 ** database filename D with corresponding journal file J and WAL file W and 3910 ** with N URI parameters key/values pairs in the array P. The result from 3911 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3912 ** is safe to pass to routines like: 3913 ** <ul> 3914 ** <li> [sqlite3_uri_parameter()], 3915 ** <li> [sqlite3_uri_boolean()], 3916 ** <li> [sqlite3_uri_int64()], 3917 ** <li> [sqlite3_uri_key()], 3918 ** <li> [sqlite3_filename_database()], 3919 ** <li> [sqlite3_filename_journal()], or 3920 ** <li> [sqlite3_filename_wal()]. 3921 ** </ul> 3922 ** If a memory allocation error occurs, sqlite3_create_filename() might 3923 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3924 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3925 ** 3926 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3927 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3928 ** to a key and value for a query parameter. The P parameter may be a NULL 3929 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3930 ** NULL pointers and key pointers should not be empty strings. 3931 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3932 ** be NULL pointers, though they can be empty strings. 3933 ** 3934 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3935 ** previously obtained from sqlite3_create_filename(). Invoking 3936 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3937 ** 3938 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3939 ** than a NULL pointer or a pointer previously acquired from 3940 ** sqlite3_create_filename(), then bad things such as heap 3941 ** corruption or segfaults may occur. The value Y should not be 3942 ** used again after sqlite3_free_filename(Y) has been called. This means 3943 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3944 ** then the corresponding [sqlite3_module.xClose() method should also be 3945 ** invoked prior to calling sqlite3_free_filename(Y). 3946 */ 3947 SQLITE_API sqlite3_filename sqlite3_create_filename( 3948 const char *zDatabase, 3949 const char *zJournal, 3950 const char *zWal, 3951 int nParam, 3952 const char **azParam 3953 ); 3954 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3955 3956 /* 3957 ** CAPI3REF: Error Codes And Messages 3958 ** METHOD: sqlite3 3959 ** 3960 ** ^If the most recent sqlite3_* API call associated with 3961 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3962 ** returns the numeric [result code] or [extended result code] for that 3963 ** API call. 3964 ** ^The sqlite3_extended_errcode() 3965 ** interface is the same except that it always returns the 3966 ** [extended result code] even when extended result codes are 3967 ** disabled. 3968 ** 3969 ** The values returned by sqlite3_errcode() and/or 3970 ** sqlite3_extended_errcode() might change with each API call. 3971 ** Except, there are some interfaces that are guaranteed to never 3972 ** change the value of the error code. The error-code preserving 3973 ** interfaces include the following: 3974 ** 3975 ** <ul> 3976 ** <li> sqlite3_errcode() 3977 ** <li> sqlite3_extended_errcode() 3978 ** <li> sqlite3_errmsg() 3979 ** <li> sqlite3_errmsg16() 3980 ** <li> sqlite3_error_offset() 3981 ** </ul> 3982 ** 3983 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3984 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3985 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.) 3986 ** ^(Memory to hold the error message string is managed internally. 3987 ** The application does not need to worry about freeing the result. 3988 ** However, the error string might be overwritten or deallocated by 3989 ** subsequent calls to other SQLite interface functions.)^ 3990 ** 3991 ** ^The sqlite3_errstr() interface returns the English-language text 3992 ** that describes the [result code], as UTF-8. 3993 ** ^(Memory to hold the error message string is managed internally 3994 ** and must not be freed by the application)^. 3995 ** 3996 ** ^If the most recent error references a specific token in the input 3997 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3998 ** of the start of that token. ^The byte offset returned by 3999 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 4000 ** ^If the most recent error does not reference a specific token in the input 4001 ** SQL, then the sqlite3_error_offset() function returns -1. 4002 ** 4003 ** When the serialized [threading mode] is in use, it might be the 4004 ** case that a second error occurs on a separate thread in between 4005 ** the time of the first error and the call to these interfaces. 4006 ** When that happens, the second error will be reported since these 4007 ** interfaces always report the most recent result. To avoid 4008 ** this, each thread can obtain exclusive use of the [database connection] D 4009 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 4010 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 4011 ** all calls to the interfaces listed here are completed. 4012 ** 4013 ** If an interface fails with SQLITE_MISUSE, that means the interface 4014 ** was invoked incorrectly by the application. In that case, the 4015 ** error code and message may or may not be set. 4016 */ 4017 SQLITE_API int sqlite3_errcode(sqlite3 *db); 4018 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 4019 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 4020 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 4021 SQLITE_API const char *sqlite3_errstr(int); 4022 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 4023 4024 /* 4025 ** CAPI3REF: Prepared Statement Object 4026 ** KEYWORDS: {prepared statement} {prepared statements} 4027 ** 4028 ** An instance of this object represents a single SQL statement that 4029 ** has been compiled into binary form and is ready to be evaluated. 4030 ** 4031 ** Think of each SQL statement as a separate computer program. The 4032 ** original SQL text is source code. A prepared statement object 4033 ** is the compiled object code. All SQL must be converted into a 4034 ** prepared statement before it can be run. 4035 ** 4036 ** The life-cycle of a prepared statement object usually goes like this: 4037 ** 4038 ** <ol> 4039 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 4040 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 4041 ** interfaces. 4042 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 4043 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 4044 ** to step 2. Do this zero or more times. 4045 ** <li> Destroy the object using [sqlite3_finalize()]. 4046 ** </ol> 4047 */ 4048 typedef struct sqlite3_stmt sqlite3_stmt; 4049 4050 /* 4051 ** CAPI3REF: Run-time Limits 4052 ** METHOD: sqlite3 4053 ** 4054 ** ^(This interface allows the size of various constructs to be limited 4055 ** on a connection by connection basis. The first parameter is the 4056 ** [database connection] whose limit is to be set or queried. The 4057 ** second parameter is one of the [limit categories] that define a 4058 ** class of constructs to be size limited. The third parameter is the 4059 ** new limit for that construct.)^ 4060 ** 4061 ** ^If the new limit is a negative number, the limit is unchanged. 4062 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 4063 ** [limits | hard upper bound] 4064 ** set at compile-time by a C preprocessor macro called 4065 ** [limits | SQLITE_MAX_<i>NAME</i>]. 4066 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 4067 ** ^Attempts to increase a limit above its hard upper bound are 4068 ** silently truncated to the hard upper bound. 4069 ** 4070 ** ^Regardless of whether or not the limit was changed, the 4071 ** [sqlite3_limit()] interface returns the prior value of the limit. 4072 ** ^Hence, to find the current value of a limit without changing it, 4073 ** simply invoke this interface with the third parameter set to -1. 4074 ** 4075 ** Run-time limits are intended for use in applications that manage 4076 ** both their own internal database and also databases that are controlled 4077 ** by untrusted external sources. An example application might be a 4078 ** web browser that has its own databases for storing history and 4079 ** separate databases controlled by JavaScript applications downloaded 4080 ** off the Internet. The internal databases can be given the 4081 ** large, default limits. Databases managed by external sources can 4082 ** be given much smaller limits designed to prevent a denial of service 4083 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4084 ** interface to further control untrusted SQL. The size of the database 4085 ** created by an untrusted script can be contained using the 4086 ** [max_page_count] [PRAGMA]. 4087 ** 4088 ** New run-time limit categories may be added in future releases. 4089 */ 4090 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4091 4092 /* 4093 ** CAPI3REF: Run-Time Limit Categories 4094 ** KEYWORDS: {limit category} {*limit categories} 4095 ** 4096 ** These constants define various performance limits 4097 ** that can be lowered at run-time using [sqlite3_limit()]. 4098 ** The synopsis of the meanings of the various limits is shown below. 4099 ** Additional information is available at [limits | Limits in SQLite]. 4100 ** 4101 ** <dl> 4102 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4103 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4104 ** 4105 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4106 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4107 ** 4108 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4109 ** <dd>The maximum number of columns in a table definition or in the 4110 ** result set of a [SELECT] or the maximum number of columns in an index 4111 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4112 ** 4113 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4114 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4115 ** 4116 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4117 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4118 ** 4119 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4120 ** <dd>The maximum number of instructions in a virtual machine program 4121 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4122 ** the equivalent tries to allocate space for more than this many opcodes 4123 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4124 ** 4125 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4126 ** <dd>The maximum number of arguments on a function.</dd>)^ 4127 ** 4128 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4129 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4130 ** 4131 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4132 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4133 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4134 ** [GLOB] operators.</dd>)^ 4135 ** 4136 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4137 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4138 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4139 ** 4140 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4141 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4142 ** 4143 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4144 ** <dd>The maximum number of auxiliary worker threads that a single 4145 ** [prepared statement] may start.</dd>)^ 4146 ** </dl> 4147 */ 4148 #define SQLITE_LIMIT_LENGTH 0 4149 #define SQLITE_LIMIT_SQL_LENGTH 1 4150 #define SQLITE_LIMIT_COLUMN 2 4151 #define SQLITE_LIMIT_EXPR_DEPTH 3 4152 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4153 #define SQLITE_LIMIT_VDBE_OP 5 4154 #define SQLITE_LIMIT_FUNCTION_ARG 6 4155 #define SQLITE_LIMIT_ATTACHED 7 4156 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4157 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4158 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4159 #define SQLITE_LIMIT_WORKER_THREADS 11 4160 4161 /* 4162 ** CAPI3REF: Prepare Flags 4163 ** 4164 ** These constants define various flags that can be passed into 4165 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4166 ** [sqlite3_prepare16_v3()] interfaces. 4167 ** 4168 ** New flags may be added in future releases of SQLite. 4169 ** 4170 ** <dl> 4171 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4172 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4173 ** that the prepared statement will be retained for a long time and 4174 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4175 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4176 ** be used just once or at most a few times and then destroyed using 4177 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4178 ** on this hint by avoiding the use of [lookaside memory] so as not to 4179 ** deplete the limited store of lookaside memory. Future versions of 4180 ** SQLite may act on this hint differently. 4181 ** 4182 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4183 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4184 ** to be required for any prepared statement that wanted to use the 4185 ** [sqlite3_normalized_sql()] interface. However, the 4186 ** [sqlite3_normalized_sql()] interface is now available to all 4187 ** prepared statements, regardless of whether or not they use this 4188 ** flag. 4189 ** 4190 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4191 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4192 ** to return an error (error code SQLITE_ERROR) if the statement uses 4193 ** any virtual tables. 4194 ** </dl> 4195 */ 4196 #define SQLITE_PREPARE_PERSISTENT 0x01 4197 #define SQLITE_PREPARE_NORMALIZE 0x02 4198 #define SQLITE_PREPARE_NO_VTAB 0x04 4199 4200 /* 4201 ** CAPI3REF: Compiling An SQL Statement 4202 ** KEYWORDS: {SQL statement compiler} 4203 ** METHOD: sqlite3 4204 ** CONSTRUCTOR: sqlite3_stmt 4205 ** 4206 ** To execute an SQL statement, it must first be compiled into a byte-code 4207 ** program using one of these routines. Or, in other words, these routines 4208 ** are constructors for the [prepared statement] object. 4209 ** 4210 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4211 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4212 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4213 ** for special purposes. 4214 ** 4215 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4216 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4217 ** as a convenience. The UTF-16 interfaces work by converting the 4218 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4219 ** 4220 ** The first argument, "db", is a [database connection] obtained from a 4221 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4222 ** [sqlite3_open16()]. The database connection must not have been closed. 4223 ** 4224 ** The second argument, "zSql", is the statement to be compiled, encoded 4225 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4226 ** and sqlite3_prepare_v3() 4227 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4228 ** and sqlite3_prepare16_v3() use UTF-16. 4229 ** 4230 ** ^If the nByte argument is negative, then zSql is read up to the 4231 ** first zero terminator. ^If nByte is positive, then it is the 4232 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4233 ** statement is generated. 4234 ** If the caller knows that the supplied string is nul-terminated, then 4235 ** there is a small performance advantage to passing an nByte parameter that 4236 ** is the number of bytes in the input string <i>including</i> 4237 ** the nul-terminator. 4238 ** 4239 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4240 ** past the end of the first SQL statement in zSql. These routines only 4241 ** compile the first statement in zSql, so *pzTail is left pointing to 4242 ** what remains uncompiled. 4243 ** 4244 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4245 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4246 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4247 ** string or a comment) then *ppStmt is set to NULL. 4248 ** The calling procedure is responsible for deleting the compiled 4249 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4250 ** ppStmt may not be NULL. 4251 ** 4252 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4253 ** otherwise an [error code] is returned. 4254 ** 4255 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4256 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4257 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4258 ** are retained for backwards compatibility, but their use is discouraged. 4259 ** ^In the "vX" interfaces, the prepared statement 4260 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4261 ** original SQL text. This causes the [sqlite3_step()] interface to 4262 ** behave differently in three ways: 4263 ** 4264 ** <ol> 4265 ** <li> 4266 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4267 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4268 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4269 ** retries will occur before sqlite3_step() gives up and returns an error. 4270 ** </li> 4271 ** 4272 ** <li> 4273 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4274 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4275 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4276 ** and the application would have to make a second call to [sqlite3_reset()] 4277 ** in order to find the underlying cause of the problem. With the "v2" prepare 4278 ** interfaces, the underlying reason for the error is returned immediately. 4279 ** </li> 4280 ** 4281 ** <li> 4282 ** ^If the specific value bound to a [parameter | host parameter] in the 4283 ** WHERE clause might influence the choice of query plan for a statement, 4284 ** then the statement will be automatically recompiled, as if there had been 4285 ** a schema change, on the first [sqlite3_step()] call following any change 4286 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4287 ** ^The specific value of a WHERE-clause [parameter] might influence the 4288 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4289 ** or [GLOB] operator or if the parameter is compared to an indexed column 4290 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4291 ** </li> 4292 ** </ol> 4293 ** 4294 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4295 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4296 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4297 ** sqlite3_prepare_v2() interface works exactly the same as 4298 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4299 */ 4300 SQLITE_API int sqlite3_prepare( 4301 sqlite3 *db, /* Database handle */ 4302 const char *zSql, /* SQL statement, UTF-8 encoded */ 4303 int nByte, /* Maximum length of zSql in bytes. */ 4304 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4305 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4306 ); 4307 SQLITE_API int sqlite3_prepare_v2( 4308 sqlite3 *db, /* Database handle */ 4309 const char *zSql, /* SQL statement, UTF-8 encoded */ 4310 int nByte, /* Maximum length of zSql in bytes. */ 4311 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4312 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4313 ); 4314 SQLITE_API int sqlite3_prepare_v3( 4315 sqlite3 *db, /* Database handle */ 4316 const char *zSql, /* SQL statement, UTF-8 encoded */ 4317 int nByte, /* Maximum length of zSql in bytes. */ 4318 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4319 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4320 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4321 ); 4322 SQLITE_API int sqlite3_prepare16( 4323 sqlite3 *db, /* Database handle */ 4324 const void *zSql, /* SQL statement, UTF-16 encoded */ 4325 int nByte, /* Maximum length of zSql in bytes. */ 4326 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4327 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4328 ); 4329 SQLITE_API int sqlite3_prepare16_v2( 4330 sqlite3 *db, /* Database handle */ 4331 const void *zSql, /* SQL statement, UTF-16 encoded */ 4332 int nByte, /* Maximum length of zSql in bytes. */ 4333 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4334 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4335 ); 4336 SQLITE_API int sqlite3_prepare16_v3( 4337 sqlite3 *db, /* Database handle */ 4338 const void *zSql, /* SQL statement, UTF-16 encoded */ 4339 int nByte, /* Maximum length of zSql in bytes. */ 4340 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4341 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4342 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4343 ); 4344 4345 /* 4346 ** CAPI3REF: Retrieving Statement SQL 4347 ** METHOD: sqlite3_stmt 4348 ** 4349 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4350 ** SQL text used to create [prepared statement] P if P was 4351 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4352 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4353 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4354 ** string containing the SQL text of prepared statement P with 4355 ** [bound parameters] expanded. 4356 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4357 ** string containing the normalized SQL text of prepared statement P. The 4358 ** semantics used to normalize a SQL statement are unspecified and subject 4359 ** to change. At a minimum, literal values will be replaced with suitable 4360 ** placeholders. 4361 ** 4362 ** ^(For example, if a prepared statement is created using the SQL 4363 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4364 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4365 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4366 ** will return "SELECT 2345,NULL".)^ 4367 ** 4368 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4369 ** is available to hold the result, or if the result would exceed the 4370 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4371 ** 4372 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4373 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4374 ** option causes sqlite3_expanded_sql() to always return NULL. 4375 ** 4376 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4377 ** are managed by SQLite and are automatically freed when the prepared 4378 ** statement is finalized. 4379 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4380 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4381 ** by passing it to [sqlite3_free()]. 4382 ** 4383 ** ^The sqlite3_normalized_sql() interface is only available if 4384 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4385 */ 4386 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4387 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4388 #ifdef SQLITE_ENABLE_NORMALIZE 4389 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4390 #endif 4391 4392 /* 4393 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4394 ** METHOD: sqlite3_stmt 4395 ** 4396 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4397 ** and only if the [prepared statement] X makes no direct changes to 4398 ** the content of the database file. 4399 ** 4400 ** Note that [application-defined SQL functions] or 4401 ** [virtual tables] might change the database indirectly as a side effect. 4402 ** ^(For example, if an application defines a function "eval()" that 4403 ** calls [sqlite3_exec()], then the following SQL statement would 4404 ** change the database file through side-effects: 4405 ** 4406 ** <blockquote><pre> 4407 ** SELECT eval('DELETE FROM t1') FROM t2; 4408 ** </pre></blockquote> 4409 ** 4410 ** But because the [SELECT] statement does not change the database file 4411 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4412 ** 4413 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4414 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4415 ** since the statements themselves do not actually modify the database but 4416 ** rather they control the timing of when other statements modify the 4417 ** database. ^The [ATTACH] and [DETACH] statements also cause 4418 ** sqlite3_stmt_readonly() to return true since, while those statements 4419 ** change the configuration of a database connection, they do not make 4420 ** changes to the content of the database files on disk. 4421 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4422 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4423 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4424 ** sqlite3_stmt_readonly() returns false for those commands. 4425 ** 4426 ** ^This routine returns false if there is any possibility that the 4427 ** statement might change the database file. ^A false return does 4428 ** not guarantee that the statement will change the database file. 4429 ** ^For example, an UPDATE statement might have a WHERE clause that 4430 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4431 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4432 ** read-only no-op if the table already exists, but 4433 ** sqlite3_stmt_readonly() still returns false for such a statement. 4434 ** 4435 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4436 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4437 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4438 */ 4439 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4440 4441 /* 4442 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4443 ** METHOD: sqlite3_stmt 4444 ** 4445 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4446 ** prepared statement S is an EXPLAIN statement, or 2 if the 4447 ** statement S is an EXPLAIN QUERY PLAN. 4448 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4449 ** an ordinary statement or a NULL pointer. 4450 */ 4451 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4452 4453 /* 4454 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement 4455 ** METHOD: sqlite3_stmt 4456 ** 4457 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN 4458 ** setting for [prepared statement] S. If E is zero, then S becomes 4459 ** a normal prepared statement. If E is 1, then S behaves as if 4460 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if 4461 ** its SQL text began with "[EXPLAIN QUERY PLAN]". 4462 ** 4463 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared. 4464 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary 4465 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode. 4466 ** 4467 ** Because of the potential need to reprepare, a call to 4468 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be 4469 ** reprepared because it was created using [sqlite3_prepare()] instead of 4470 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and 4471 ** hence has no saved SQL text with which to reprepare. 4472 ** 4473 ** Changing the explain setting for a prepared statement does not change 4474 ** the original SQL text for the statement. Hence, if the SQL text originally 4475 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0) 4476 ** is called to convert the statement into an ordinary statement, the EXPLAIN 4477 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S) 4478 ** output, even though the statement now acts like a normal SQL statement. 4479 ** 4480 ** This routine returns SQLITE_OK if the explain mode is successfully 4481 ** changed, or an error code if the explain mode could not be changed. 4482 ** The explain mode cannot be changed while a statement is active. 4483 ** Hence, it is good practice to call [sqlite3_reset(S)] 4484 ** immediately prior to calling sqlite3_stmt_explain(S,E). 4485 */ 4486 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode); 4487 4488 /* 4489 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4490 ** METHOD: sqlite3_stmt 4491 ** 4492 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4493 ** [prepared statement] S has been stepped at least once using 4494 ** [sqlite3_step(S)] but has neither run to completion (returned 4495 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4496 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4497 ** interface returns false if S is a NULL pointer. If S is not a 4498 ** NULL pointer and is not a pointer to a valid [prepared statement] 4499 ** object, then the behavior is undefined and probably undesirable. 4500 ** 4501 ** This interface can be used in combination [sqlite3_next_stmt()] 4502 ** to locate all prepared statements associated with a database 4503 ** connection that are in need of being reset. This can be used, 4504 ** for example, in diagnostic routines to search for prepared 4505 ** statements that are holding a transaction open. 4506 */ 4507 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4508 4509 /* 4510 ** CAPI3REF: Dynamically Typed Value Object 4511 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4512 ** 4513 ** SQLite uses the sqlite3_value object to represent all values 4514 ** that can be stored in a database table. SQLite uses dynamic typing 4515 ** for the values it stores. ^Values stored in sqlite3_value objects 4516 ** can be integers, floating point values, strings, BLOBs, or NULL. 4517 ** 4518 ** An sqlite3_value object may be either "protected" or "unprotected". 4519 ** Some interfaces require a protected sqlite3_value. Other interfaces 4520 ** will accept either a protected or an unprotected sqlite3_value. 4521 ** Every interface that accepts sqlite3_value arguments specifies 4522 ** whether or not it requires a protected sqlite3_value. The 4523 ** [sqlite3_value_dup()] interface can be used to construct a new 4524 ** protected sqlite3_value from an unprotected sqlite3_value. 4525 ** 4526 ** The terms "protected" and "unprotected" refer to whether or not 4527 ** a mutex is held. An internal mutex is held for a protected 4528 ** sqlite3_value object but no mutex is held for an unprotected 4529 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4530 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4531 ** or if SQLite is run in one of reduced mutex modes 4532 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4533 ** then there is no distinction between protected and unprotected 4534 ** sqlite3_value objects and they can be used interchangeably. However, 4535 ** for maximum code portability it is recommended that applications 4536 ** still make the distinction between protected and unprotected 4537 ** sqlite3_value objects even when not strictly required. 4538 ** 4539 ** ^The sqlite3_value objects that are passed as parameters into the 4540 ** implementation of [application-defined SQL functions] are protected. 4541 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4542 ** are protected. 4543 ** ^The sqlite3_value object returned by 4544 ** [sqlite3_column_value()] is unprotected. 4545 ** Unprotected sqlite3_value objects may only be used as arguments 4546 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4547 ** [sqlite3_value_dup()]. 4548 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4549 ** interfaces require protected sqlite3_value objects. 4550 */ 4551 typedef struct sqlite3_value sqlite3_value; 4552 4553 /* 4554 ** CAPI3REF: SQL Function Context Object 4555 ** 4556 ** The context in which an SQL function executes is stored in an 4557 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4558 ** is always first parameter to [application-defined SQL functions]. 4559 ** The application-defined SQL function implementation will pass this 4560 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4561 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4562 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4563 ** and/or [sqlite3_set_auxdata()]. 4564 */ 4565 typedef struct sqlite3_context sqlite3_context; 4566 4567 /* 4568 ** CAPI3REF: Binding Values To Prepared Statements 4569 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4570 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4571 ** METHOD: sqlite3_stmt 4572 ** 4573 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4574 ** literals may be replaced by a [parameter] that matches one of following 4575 ** templates: 4576 ** 4577 ** <ul> 4578 ** <li> ? 4579 ** <li> ?NNN 4580 ** <li> :VVV 4581 ** <li> @VVV 4582 ** <li> $VVV 4583 ** </ul> 4584 ** 4585 ** In the templates above, NNN represents an integer literal, 4586 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4587 ** parameters (also called "host parameter names" or "SQL parameters") 4588 ** can be set using the sqlite3_bind_*() routines defined here. 4589 ** 4590 ** ^The first argument to the sqlite3_bind_*() routines is always 4591 ** a pointer to the [sqlite3_stmt] object returned from 4592 ** [sqlite3_prepare_v2()] or its variants. 4593 ** 4594 ** ^The second argument is the index of the SQL parameter to be set. 4595 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4596 ** SQL parameter is used more than once, second and subsequent 4597 ** occurrences have the same index as the first occurrence. 4598 ** ^The index for named parameters can be looked up using the 4599 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4600 ** for "?NNN" parameters is the value of NNN. 4601 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4602 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4603 ** 4604 ** ^The third argument is the value to bind to the parameter. 4605 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4606 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4607 ** is ignored and the end result is the same as sqlite3_bind_null(). 4608 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4609 ** it should be a pointer to well-formed UTF8 text. 4610 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4611 ** it should be a pointer to well-formed UTF16 text. 4612 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4613 ** it should be a pointer to a well-formed unicode string that is 4614 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4615 ** otherwise. 4616 ** 4617 ** [[byte-order determination rules]] ^The byte-order of 4618 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4619 ** found in first character, which is removed, or in the absence of a BOM 4620 ** the byte order is the native byte order of the host 4621 ** machine for sqlite3_bind_text16() or the byte order specified in 4622 ** the 6th parameter for sqlite3_bind_text64().)^ 4623 ** ^If UTF16 input text contains invalid unicode 4624 ** characters, then SQLite might change those invalid characters 4625 ** into the unicode replacement character: U+FFFD. 4626 ** 4627 ** ^(In those routines that have a fourth argument, its value is the 4628 ** number of bytes in the parameter. To be clear: the value is the 4629 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4630 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4631 ** is negative, then the length of the string is 4632 ** the number of bytes up to the first zero terminator. 4633 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4634 ** the behavior is undefined. 4635 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4636 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4637 ** that parameter must be the byte offset 4638 ** where the NUL terminator would occur assuming the string were NUL 4639 ** terminated. If any NUL characters occurs at byte offsets less than 4640 ** the value of the fourth parameter then the resulting string value will 4641 ** contain embedded NULs. The result of expressions involving strings 4642 ** with embedded NULs is undefined. 4643 ** 4644 ** ^The fifth argument to the BLOB and string binding interfaces controls 4645 ** or indicates the lifetime of the object referenced by the third parameter. 4646 ** These three options exist: 4647 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4648 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4649 ** if the call to the bind API fails, except the destructor is not called if 4650 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4651 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that 4652 ** the application remains responsible for disposing of the object. ^In this 4653 ** case, the object and the provided pointer to it must remain valid until 4654 ** either the prepared statement is finalized or the same SQL parameter is 4655 ** bound to something else, whichever occurs sooner. 4656 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4657 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4658 ** object and pointer to it must remain valid until then. ^SQLite will then 4659 ** manage the lifetime of its private copy. 4660 ** 4661 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4662 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4663 ** to specify the encoding of the text in the third parameter. If 4664 ** the sixth argument to sqlite3_bind_text64() is not one of the 4665 ** allowed values shown above, or if the text encoding is different 4666 ** from the encoding specified by the sixth parameter, then the behavior 4667 ** is undefined. 4668 ** 4669 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4670 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4671 ** (just an integer to hold its size) while it is being processed. 4672 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4673 ** content is later written using 4674 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4675 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4676 ** 4677 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4678 ** [prepared statement] S to have an SQL value of NULL, but to also be 4679 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4680 ** a pointer to a destructor function for P. ^SQLite will invoke the 4681 ** destructor D with a single argument of P when it is finished using 4682 ** P. The T parameter should be a static string, preferably a string 4683 ** literal. The sqlite3_bind_pointer() routine is part of the 4684 ** [pointer passing interface] added for SQLite 3.20.0. 4685 ** 4686 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4687 ** for the [prepared statement] or with a prepared statement for which 4688 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4689 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4690 ** routine is passed a [prepared statement] that has been finalized, the 4691 ** result is undefined and probably harmful. 4692 ** 4693 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4694 ** ^Unbound parameters are interpreted as NULL. 4695 ** 4696 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4697 ** [error code] if anything goes wrong. 4698 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4699 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4700 ** [SQLITE_MAX_LENGTH]. 4701 ** ^[SQLITE_RANGE] is returned if the parameter 4702 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4703 ** 4704 ** See also: [sqlite3_bind_parameter_count()], 4705 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4706 */ 4707 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4708 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4709 void(*)(void*)); 4710 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4711 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4712 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4713 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4714 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4715 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4716 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4717 void(*)(void*), unsigned char encoding); 4718 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4719 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4720 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4721 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4722 4723 /* 4724 ** CAPI3REF: Number Of SQL Parameters 4725 ** METHOD: sqlite3_stmt 4726 ** 4727 ** ^This routine can be used to find the number of [SQL parameters] 4728 ** in a [prepared statement]. SQL parameters are tokens of the 4729 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4730 ** placeholders for values that are [sqlite3_bind_blob | bound] 4731 ** to the parameters at a later time. 4732 ** 4733 ** ^(This routine actually returns the index of the largest (rightmost) 4734 ** parameter. For all forms except ?NNN, this will correspond to the 4735 ** number of unique parameters. If parameters of the ?NNN form are used, 4736 ** there may be gaps in the list.)^ 4737 ** 4738 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4739 ** [sqlite3_bind_parameter_name()], and 4740 ** [sqlite3_bind_parameter_index()]. 4741 */ 4742 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4743 4744 /* 4745 ** CAPI3REF: Name Of A Host Parameter 4746 ** METHOD: sqlite3_stmt 4747 ** 4748 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4749 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4750 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4751 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4752 ** respectively. 4753 ** In other words, the initial ":" or "$" or "@" or "?" 4754 ** is included as part of the name.)^ 4755 ** ^Parameters of the form "?" without a following integer have no name 4756 ** and are referred to as "nameless" or "anonymous parameters". 4757 ** 4758 ** ^The first host parameter has an index of 1, not 0. 4759 ** 4760 ** ^If the value N is out of range or if the N-th parameter is 4761 ** nameless, then NULL is returned. ^The returned string is 4762 ** always in UTF-8 encoding even if the named parameter was 4763 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4764 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4765 ** 4766 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4767 ** [sqlite3_bind_parameter_count()], and 4768 ** [sqlite3_bind_parameter_index()]. 4769 */ 4770 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4771 4772 /* 4773 ** CAPI3REF: Index Of A Parameter With A Given Name 4774 ** METHOD: sqlite3_stmt 4775 ** 4776 ** ^Return the index of an SQL parameter given its name. ^The 4777 ** index value returned is suitable for use as the second 4778 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4779 ** is returned if no matching parameter is found. ^The parameter 4780 ** name must be given in UTF-8 even if the original statement 4781 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4782 ** [sqlite3_prepare16_v3()]. 4783 ** 4784 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4785 ** [sqlite3_bind_parameter_count()], and 4786 ** [sqlite3_bind_parameter_name()]. 4787 */ 4788 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4789 4790 /* 4791 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4792 ** METHOD: sqlite3_stmt 4793 ** 4794 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4795 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4796 ** ^Use this routine to reset all host parameters to NULL. 4797 */ 4798 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4799 4800 /* 4801 ** CAPI3REF: Number Of Columns In A Result Set 4802 ** METHOD: sqlite3_stmt 4803 ** 4804 ** ^Return the number of columns in the result set returned by the 4805 ** [prepared statement]. ^If this routine returns 0, that means the 4806 ** [prepared statement] returns no data (for example an [UPDATE]). 4807 ** ^However, just because this routine returns a positive number does not 4808 ** mean that one or more rows of data will be returned. ^A SELECT statement 4809 ** will always have a positive sqlite3_column_count() but depending on the 4810 ** WHERE clause constraints and the table content, it might return no rows. 4811 ** 4812 ** See also: [sqlite3_data_count()] 4813 */ 4814 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4815 4816 /* 4817 ** CAPI3REF: Column Names In A Result Set 4818 ** METHOD: sqlite3_stmt 4819 ** 4820 ** ^These routines return the name assigned to a particular column 4821 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4822 ** interface returns a pointer to a zero-terminated UTF-8 string 4823 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4824 ** UTF-16 string. ^The first parameter is the [prepared statement] 4825 ** that implements the [SELECT] statement. ^The second parameter is the 4826 ** column number. ^The leftmost column is number 0. 4827 ** 4828 ** ^The returned string pointer is valid until either the [prepared statement] 4829 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4830 ** reprepared by the first call to [sqlite3_step()] for a particular run 4831 ** or until the next call to 4832 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4833 ** 4834 ** ^If sqlite3_malloc() fails during the processing of either routine 4835 ** (for example during a conversion from UTF-8 to UTF-16) then a 4836 ** NULL pointer is returned. 4837 ** 4838 ** ^The name of a result column is the value of the "AS" clause for 4839 ** that column, if there is an AS clause. If there is no AS clause 4840 ** then the name of the column is unspecified and may change from 4841 ** one release of SQLite to the next. 4842 */ 4843 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4844 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4845 4846 /* 4847 ** CAPI3REF: Source Of Data In A Query Result 4848 ** METHOD: sqlite3_stmt 4849 ** 4850 ** ^These routines provide a means to determine the database, table, and 4851 ** table column that is the origin of a particular result column in 4852 ** [SELECT] statement. 4853 ** ^The name of the database or table or column can be returned as 4854 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4855 ** the database name, the _table_ routines return the table name, and 4856 ** the origin_ routines return the column name. 4857 ** ^The returned string is valid until the [prepared statement] is destroyed 4858 ** using [sqlite3_finalize()] or until the statement is automatically 4859 ** reprepared by the first call to [sqlite3_step()] for a particular run 4860 ** or until the same information is requested 4861 ** again in a different encoding. 4862 ** 4863 ** ^The names returned are the original un-aliased names of the 4864 ** database, table, and column. 4865 ** 4866 ** ^The first argument to these interfaces is a [prepared statement]. 4867 ** ^These functions return information about the Nth result column returned by 4868 ** the statement, where N is the second function argument. 4869 ** ^The left-most column is column 0 for these routines. 4870 ** 4871 ** ^If the Nth column returned by the statement is an expression or 4872 ** subquery and is not a column value, then all of these functions return 4873 ** NULL. ^These routines might also return NULL if a memory allocation error 4874 ** occurs. ^Otherwise, they return the name of the attached database, table, 4875 ** or column that query result column was extracted from. 4876 ** 4877 ** ^As with all other SQLite APIs, those whose names end with "16" return 4878 ** UTF-16 encoded strings and the other functions return UTF-8. 4879 ** 4880 ** ^These APIs are only available if the library was compiled with the 4881 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4882 ** 4883 ** If two or more threads call one or more 4884 ** [sqlite3_column_database_name | column metadata interfaces] 4885 ** for the same [prepared statement] and result column 4886 ** at the same time then the results are undefined. 4887 */ 4888 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4889 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4890 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4891 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4892 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4893 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4894 4895 /* 4896 ** CAPI3REF: Declared Datatype Of A Query Result 4897 ** METHOD: sqlite3_stmt 4898 ** 4899 ** ^(The first parameter is a [prepared statement]. 4900 ** If this statement is a [SELECT] statement and the Nth column of the 4901 ** returned result set of that [SELECT] is a table column (not an 4902 ** expression or subquery) then the declared type of the table 4903 ** column is returned.)^ ^If the Nth column of the result set is an 4904 ** expression or subquery, then a NULL pointer is returned. 4905 ** ^The returned string is always UTF-8 encoded. 4906 ** 4907 ** ^(For example, given the database schema: 4908 ** 4909 ** CREATE TABLE t1(c1 VARIANT); 4910 ** 4911 ** and the following statement to be compiled: 4912 ** 4913 ** SELECT c1 + 1, c1 FROM t1; 4914 ** 4915 ** this routine would return the string "VARIANT" for the second result 4916 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4917 ** 4918 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4919 ** is declared to contain a particular type does not mean that the 4920 ** data stored in that column is of the declared type. SQLite is 4921 ** strongly typed, but the typing is dynamic not static. ^Type 4922 ** is associated with individual values, not with the containers 4923 ** used to hold those values. 4924 */ 4925 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4926 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4927 4928 /* 4929 ** CAPI3REF: Evaluate An SQL Statement 4930 ** METHOD: sqlite3_stmt 4931 ** 4932 ** After a [prepared statement] has been prepared using any of 4933 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4934 ** or [sqlite3_prepare16_v3()] or one of the legacy 4935 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4936 ** must be called one or more times to evaluate the statement. 4937 ** 4938 ** The details of the behavior of the sqlite3_step() interface depend 4939 ** on whether the statement was prepared using the newer "vX" interfaces 4940 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4941 ** [sqlite3_prepare16_v2()] or the older legacy 4942 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4943 ** new "vX" interface is recommended for new applications but the legacy 4944 ** interface will continue to be supported. 4945 ** 4946 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4947 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4948 ** ^With the "v2" interface, any of the other [result codes] or 4949 ** [extended result codes] might be returned as well. 4950 ** 4951 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4952 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4953 ** or occurs outside of an explicit transaction, then you can retry the 4954 ** statement. If the statement is not a [COMMIT] and occurs within an 4955 ** explicit transaction then you should rollback the transaction before 4956 ** continuing. 4957 ** 4958 ** ^[SQLITE_DONE] means that the statement has finished executing 4959 ** successfully. sqlite3_step() should not be called again on this virtual 4960 ** machine without first calling [sqlite3_reset()] to reset the virtual 4961 ** machine back to its initial state. 4962 ** 4963 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4964 ** is returned each time a new row of data is ready for processing by the 4965 ** caller. The values may be accessed using the [column access functions]. 4966 ** sqlite3_step() is called again to retrieve the next row of data. 4967 ** 4968 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4969 ** violation) has occurred. sqlite3_step() should not be called again on 4970 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4971 ** ^With the legacy interface, a more specific error code (for example, 4972 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4973 ** can be obtained by calling [sqlite3_reset()] on the 4974 ** [prepared statement]. ^In the "v2" interface, 4975 ** the more specific error code is returned directly by sqlite3_step(). 4976 ** 4977 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4978 ** Perhaps it was called on a [prepared statement] that has 4979 ** already been [sqlite3_finalize | finalized] or on one that had 4980 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4981 ** be the case that the same database connection is being used by two or 4982 ** more threads at the same moment in time. 4983 ** 4984 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4985 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4986 ** other than [SQLITE_ROW] before any subsequent invocation of 4987 ** sqlite3_step(). Failure to reset the prepared statement using 4988 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4989 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4990 ** sqlite3_step() began 4991 ** calling [sqlite3_reset()] automatically in this circumstance rather 4992 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4993 ** break because any application that ever receives an SQLITE_MISUSE error 4994 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4995 ** can be used to restore the legacy behavior. 4996 ** 4997 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4998 ** API always returns a generic error code, [SQLITE_ERROR], following any 4999 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 5000 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 5001 ** specific [error codes] that better describes the error. 5002 ** We admit that this is a goofy design. The problem has been fixed 5003 ** with the "v2" interface. If you prepare all of your SQL statements 5004 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 5005 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 5006 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 5007 ** then the more specific [error codes] are returned directly 5008 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 5009 */ 5010 SQLITE_API int sqlite3_step(sqlite3_stmt*); 5011 5012 /* 5013 ** CAPI3REF: Number of columns in a result set 5014 ** METHOD: sqlite3_stmt 5015 ** 5016 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 5017 ** current row of the result set of [prepared statement] P. 5018 ** ^If prepared statement P does not have results ready to return 5019 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 5020 ** interfaces) then sqlite3_data_count(P) returns 0. 5021 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 5022 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 5023 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 5024 ** will return non-zero if previous call to [sqlite3_step](P) returned 5025 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 5026 ** where it always returns zero since each step of that multi-step 5027 ** pragma returns 0 columns of data. 5028 ** 5029 ** See also: [sqlite3_column_count()] 5030 */ 5031 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 5032 5033 /* 5034 ** CAPI3REF: Fundamental Datatypes 5035 ** KEYWORDS: SQLITE_TEXT 5036 ** 5037 ** ^(Every value in SQLite has one of five fundamental datatypes: 5038 ** 5039 ** <ul> 5040 ** <li> 64-bit signed integer 5041 ** <li> 64-bit IEEE floating point number 5042 ** <li> string 5043 ** <li> BLOB 5044 ** <li> NULL 5045 ** </ul>)^ 5046 ** 5047 ** These constants are codes for each of those types. 5048 ** 5049 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 5050 ** for a completely different meaning. Software that links against both 5051 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 5052 ** SQLITE_TEXT. 5053 */ 5054 #define SQLITE_INTEGER 1 5055 #define SQLITE_FLOAT 2 5056 #define SQLITE_BLOB 4 5057 #define SQLITE_NULL 5 5058 #ifdef SQLITE_TEXT 5059 # undef SQLITE_TEXT 5060 #else 5061 # define SQLITE_TEXT 3 5062 #endif 5063 #define SQLITE3_TEXT 3 5064 5065 /* 5066 ** CAPI3REF: Result Values From A Query 5067 ** KEYWORDS: {column access functions} 5068 ** METHOD: sqlite3_stmt 5069 ** 5070 ** <b>Summary:</b> 5071 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5072 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 5073 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 5074 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 5075 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 5076 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 5077 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 5078 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 5079 ** [sqlite3_value|unprotected sqlite3_value] object. 5080 ** <tr><td> <td> <td> 5081 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 5082 ** or a UTF-8 TEXT result in bytes 5083 ** <tr><td><b>sqlite3_column_bytes16 </b> 5084 ** <td>→ <td>Size of UTF-16 5085 ** TEXT in bytes 5086 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 5087 ** datatype of the result 5088 ** </table></blockquote> 5089 ** 5090 ** <b>Details:</b> 5091 ** 5092 ** ^These routines return information about a single column of the current 5093 ** result row of a query. ^In every case the first argument is a pointer 5094 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 5095 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 5096 ** and the second argument is the index of the column for which information 5097 ** should be returned. ^The leftmost column of the result set has the index 0. 5098 ** ^The number of columns in the result can be determined using 5099 ** [sqlite3_column_count()]. 5100 ** 5101 ** If the SQL statement does not currently point to a valid row, or if the 5102 ** column index is out of range, the result is undefined. 5103 ** These routines may only be called when the most recent call to 5104 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 5105 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 5106 ** If any of these routines are called after [sqlite3_reset()] or 5107 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 5108 ** something other than [SQLITE_ROW], the results are undefined. 5109 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 5110 ** are called from a different thread while any of these routines 5111 ** are pending, then the results are undefined. 5112 ** 5113 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 5114 ** each return the value of a result column in a specific data format. If 5115 ** the result column is not initially in the requested format (for example, 5116 ** if the query returns an integer but the sqlite3_column_text() interface 5117 ** is used to extract the value) then an automatic type conversion is performed. 5118 ** 5119 ** ^The sqlite3_column_type() routine returns the 5120 ** [SQLITE_INTEGER | datatype code] for the initial data type 5121 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5122 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5123 ** The return value of sqlite3_column_type() can be used to decide which 5124 ** of the first six interface should be used to extract the column value. 5125 ** The value returned by sqlite3_column_type() is only meaningful if no 5126 ** automatic type conversions have occurred for the value in question. 5127 ** After a type conversion, the result of calling sqlite3_column_type() 5128 ** is undefined, though harmless. Future 5129 ** versions of SQLite may change the behavior of sqlite3_column_type() 5130 ** following a type conversion. 5131 ** 5132 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5133 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5134 ** of that BLOB or string. 5135 ** 5136 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5137 ** routine returns the number of bytes in that BLOB or string. 5138 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5139 ** the string to UTF-8 and then returns the number of bytes. 5140 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5141 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5142 ** the number of bytes in that string. 5143 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5144 ** 5145 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5146 ** routine returns the number of bytes in that BLOB or string. 5147 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5148 ** the string to UTF-16 and then returns the number of bytes. 5149 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5150 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5151 ** the number of bytes in that string. 5152 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5153 ** 5154 ** ^The values returned by [sqlite3_column_bytes()] and 5155 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5156 ** of the string. ^For clarity: the values returned by 5157 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5158 ** bytes in the string, not the number of characters. 5159 ** 5160 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5161 ** even empty strings, are always zero-terminated. ^The return 5162 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5163 ** 5164 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5165 ** which is native to the platform, regardless of the text encoding set 5166 ** for the database. 5167 ** 5168 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5169 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5170 ** an unprotected sqlite3_value object may only be used safely with 5171 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5172 ** If the [unprotected sqlite3_value] object returned by 5173 ** [sqlite3_column_value()] is used in any other way, including calls 5174 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5175 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5176 ** Hence, the sqlite3_column_value() interface 5177 ** is normally only useful within the implementation of 5178 ** [application-defined SQL functions] or [virtual tables], not within 5179 ** top-level application code. 5180 ** 5181 ** These routines may attempt to convert the datatype of the result. 5182 ** ^For example, if the internal representation is FLOAT and a text result 5183 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5184 ** conversion automatically. ^(The following table details the conversions 5185 ** that are applied: 5186 ** 5187 ** <blockquote> 5188 ** <table border="1"> 5189 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5190 ** 5191 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5192 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5193 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5194 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5195 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5196 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5197 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5198 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5199 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5200 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5201 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5202 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5203 ** <tr><td> TEXT <td> BLOB <td> No change 5204 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5205 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5206 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5207 ** </table> 5208 ** </blockquote>)^ 5209 ** 5210 ** Note that when type conversions occur, pointers returned by prior 5211 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5212 ** sqlite3_column_text16() may be invalidated. 5213 ** Type conversions and pointer invalidations might occur 5214 ** in the following cases: 5215 ** 5216 ** <ul> 5217 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5218 ** sqlite3_column_text16() is called. A zero-terminator might 5219 ** need to be added to the string.</li> 5220 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5221 ** sqlite3_column_text16() is called. The content must be converted 5222 ** to UTF-16.</li> 5223 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5224 ** sqlite3_column_text() is called. The content must be converted 5225 ** to UTF-8.</li> 5226 ** </ul> 5227 ** 5228 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5229 ** not invalidate a prior pointer, though of course the content of the buffer 5230 ** that the prior pointer references will have been modified. Other kinds 5231 ** of conversion are done in place when it is possible, but sometimes they 5232 ** are not possible and in those cases prior pointers are invalidated. 5233 ** 5234 ** The safest policy is to invoke these routines 5235 ** in one of the following ways: 5236 ** 5237 ** <ul> 5238 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5239 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5240 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5241 ** </ul> 5242 ** 5243 ** In other words, you should call sqlite3_column_text(), 5244 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5245 ** into the desired format, then invoke sqlite3_column_bytes() or 5246 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5247 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5248 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5249 ** with calls to sqlite3_column_bytes(). 5250 ** 5251 ** ^The pointers returned are valid until a type conversion occurs as 5252 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5253 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5254 ** and BLOBs is freed automatically. Do not pass the pointers returned 5255 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5256 ** [sqlite3_free()]. 5257 ** 5258 ** As long as the input parameters are correct, these routines will only 5259 ** fail if an out-of-memory error occurs during a format conversion. 5260 ** Only the following subset of interfaces are subject to out-of-memory 5261 ** errors: 5262 ** 5263 ** <ul> 5264 ** <li> sqlite3_column_blob() 5265 ** <li> sqlite3_column_text() 5266 ** <li> sqlite3_column_text16() 5267 ** <li> sqlite3_column_bytes() 5268 ** <li> sqlite3_column_bytes16() 5269 ** </ul> 5270 ** 5271 ** If an out-of-memory error occurs, then the return value from these 5272 ** routines is the same as if the column had contained an SQL NULL value. 5273 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5274 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5275 ** return value is obtained and before any 5276 ** other SQLite interface is called on the same [database connection]. 5277 */ 5278 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5279 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5280 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5281 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5282 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5283 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5284 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5285 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5286 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5287 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5288 5289 /* 5290 ** CAPI3REF: Destroy A Prepared Statement Object 5291 ** DESTRUCTOR: sqlite3_stmt 5292 ** 5293 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5294 ** ^If the most recent evaluation of the statement encountered no errors 5295 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5296 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5297 ** sqlite3_finalize(S) returns the appropriate [error code] or 5298 ** [extended error code]. 5299 ** 5300 ** ^The sqlite3_finalize(S) routine can be called at any point during 5301 ** the life cycle of [prepared statement] S: 5302 ** before statement S is ever evaluated, after 5303 ** one or more calls to [sqlite3_reset()], or after any call 5304 ** to [sqlite3_step()] regardless of whether or not the statement has 5305 ** completed execution. 5306 ** 5307 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5308 ** 5309 ** The application must finalize every [prepared statement] in order to avoid 5310 ** resource leaks. It is a grievous error for the application to try to use 5311 ** a prepared statement after it has been finalized. Any use of a prepared 5312 ** statement after it has been finalized can result in undefined and 5313 ** undesirable behavior such as segfaults and heap corruption. 5314 */ 5315 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5316 5317 /* 5318 ** CAPI3REF: Reset A Prepared Statement Object 5319 ** METHOD: sqlite3_stmt 5320 ** 5321 ** The sqlite3_reset() function is called to reset a [prepared statement] 5322 ** object back to its initial state, ready to be re-executed. 5323 ** ^Any SQL statement variables that had values bound to them using 5324 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5325 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5326 ** 5327 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5328 ** back to the beginning of its program. 5329 ** 5330 ** ^The return code from [sqlite3_reset(S)] indicates whether or not 5331 ** the previous evaluation of prepared statement S completed successfully. 5332 ** ^If [sqlite3_step(S)] has never before been called on S or if 5333 ** [sqlite3_step(S)] has not been called since the previous call 5334 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return 5335 ** [SQLITE_OK]. 5336 ** 5337 ** ^If the most recent call to [sqlite3_step(S)] for the 5338 ** [prepared statement] S indicated an error, then 5339 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5340 ** ^The [sqlite3_reset(S)] interface might also return an [error code] 5341 ** if there were no prior errors but the process of resetting 5342 ** the prepared statement caused a new error. ^For example, if an 5343 ** [INSERT] statement with a [RETURNING] clause is only stepped one time, 5344 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but 5345 ** the overall statement might still fail and the [sqlite3_reset(S)] call 5346 ** might return SQLITE_BUSY if locking constraints prevent the 5347 ** database change from committing. Therefore, it is important that 5348 ** applications check the return code from [sqlite3_reset(S)] even if 5349 ** no prior call to [sqlite3_step(S)] indicated a problem. 5350 ** 5351 ** ^The [sqlite3_reset(S)] interface does not change the values 5352 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5353 */ 5354 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5355 5356 5357 /* 5358 ** CAPI3REF: Create Or Redefine SQL Functions 5359 ** KEYWORDS: {function creation routines} 5360 ** METHOD: sqlite3 5361 ** 5362 ** ^These functions (collectively known as "function creation routines") 5363 ** are used to add SQL functions or aggregates or to redefine the behavior 5364 ** of existing SQL functions or aggregates. The only differences between 5365 ** the three "sqlite3_create_function*" routines are the text encoding 5366 ** expected for the second parameter (the name of the function being 5367 ** created) and the presence or absence of a destructor callback for 5368 ** the application data pointer. Function sqlite3_create_window_function() 5369 ** is similar, but allows the user to supply the extra callback functions 5370 ** needed by [aggregate window functions]. 5371 ** 5372 ** ^The first parameter is the [database connection] to which the SQL 5373 ** function is to be added. ^If an application uses more than one database 5374 ** connection then application-defined SQL functions must be added 5375 ** to each database connection separately. 5376 ** 5377 ** ^The second parameter is the name of the SQL function to be created or 5378 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5379 ** representation, exclusive of the zero-terminator. ^Note that the name 5380 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5381 ** ^Any attempt to create a function with a longer name 5382 ** will result in [SQLITE_MISUSE] being returned. 5383 ** 5384 ** ^The third parameter (nArg) 5385 ** is the number of arguments that the SQL function or 5386 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5387 ** aggregate may take any number of arguments between 0 and the limit 5388 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5389 ** parameter is less than -1 or greater than 127 then the behavior is 5390 ** undefined. 5391 ** 5392 ** ^The fourth parameter, eTextRep, specifies what 5393 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5394 ** its parameters. The application should set this parameter to 5395 ** [SQLITE_UTF16LE] if the function implementation invokes 5396 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5397 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5398 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5399 ** otherwise. ^The same SQL function may be registered multiple times using 5400 ** different preferred text encodings, with different implementations for 5401 ** each encoding. 5402 ** ^When multiple implementations of the same function are available, SQLite 5403 ** will pick the one that involves the least amount of data conversion. 5404 ** 5405 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5406 ** to signal that the function will always return the same result given 5407 ** the same inputs within a single SQL statement. Most SQL functions are 5408 ** deterministic. The built-in [random()] SQL function is an example of a 5409 ** function that is not deterministic. The SQLite query planner is able to 5410 ** perform additional optimizations on deterministic functions, so use 5411 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5412 ** 5413 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5414 ** flag, which if present prevents the function from being invoked from 5415 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5416 ** index expressions, or the WHERE clause of partial indexes. 5417 ** 5418 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5419 ** all application-defined SQL functions that do not need to be 5420 ** used inside of triggers, view, CHECK constraints, or other elements of 5421 ** the database schema. This flags is especially recommended for SQL 5422 ** functions that have side effects or reveal internal application state. 5423 ** Without this flag, an attacker might be able to modify the schema of 5424 ** a database file to include invocations of the function with parameters 5425 ** chosen by the attacker, which the application will then execute when 5426 ** the database file is opened and read. 5427 ** 5428 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5429 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5430 ** 5431 ** ^The sixth, seventh and eighth parameters passed to the three 5432 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5433 ** pointers to C-language functions that implement the SQL function or 5434 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5435 ** callback only; NULL pointers must be passed as the xStep and xFinal 5436 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5437 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5438 ** SQL function or aggregate, pass NULL pointers for all three function 5439 ** callbacks. 5440 ** 5441 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5442 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5443 ** C-language callbacks that implement the new function. xStep and xFinal 5444 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5445 ** which case a regular aggregate function is created, or must both be 5446 ** non-NULL, in which case the new function may be used as either an aggregate 5447 ** or aggregate window function. More details regarding the implementation 5448 ** of aggregate window functions are 5449 ** [user-defined window functions|available here]. 5450 ** 5451 ** ^(If the final parameter to sqlite3_create_function_v2() or 5452 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5453 ** the application data pointer. The destructor is invoked when the function 5454 ** is deleted, either by being overloaded or when the database connection 5455 ** closes.)^ ^The destructor is also invoked if the call to 5456 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5457 ** invoked, it is passed a single argument which is a copy of the application 5458 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5459 ** 5460 ** ^It is permitted to register multiple implementations of the same 5461 ** functions with the same name but with either differing numbers of 5462 ** arguments or differing preferred text encodings. ^SQLite will use 5463 ** the implementation that most closely matches the way in which the 5464 ** SQL function is used. ^A function implementation with a non-negative 5465 ** nArg parameter is a better match than a function implementation with 5466 ** a negative nArg. ^A function where the preferred text encoding 5467 ** matches the database encoding is a better 5468 ** match than a function where the encoding is different. 5469 ** ^A function where the encoding difference is between UTF16le and UTF16be 5470 ** is a closer match than a function where the encoding difference is 5471 ** between UTF8 and UTF16. 5472 ** 5473 ** ^Built-in functions may be overloaded by new application-defined functions. 5474 ** 5475 ** ^An application-defined function is permitted to call other 5476 ** SQLite interfaces. However, such calls must not 5477 ** close the database connection nor finalize or reset the prepared 5478 ** statement in which the function is running. 5479 */ 5480 SQLITE_API int sqlite3_create_function( 5481 sqlite3 *db, 5482 const char *zFunctionName, 5483 int nArg, 5484 int eTextRep, 5485 void *pApp, 5486 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5487 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5488 void (*xFinal)(sqlite3_context*) 5489 ); 5490 SQLITE_API int sqlite3_create_function16( 5491 sqlite3 *db, 5492 const void *zFunctionName, 5493 int nArg, 5494 int eTextRep, 5495 void *pApp, 5496 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5497 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5498 void (*xFinal)(sqlite3_context*) 5499 ); 5500 SQLITE_API int sqlite3_create_function_v2( 5501 sqlite3 *db, 5502 const char *zFunctionName, 5503 int nArg, 5504 int eTextRep, 5505 void *pApp, 5506 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5507 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5508 void (*xFinal)(sqlite3_context*), 5509 void(*xDestroy)(void*) 5510 ); 5511 SQLITE_API int sqlite3_create_window_function( 5512 sqlite3 *db, 5513 const char *zFunctionName, 5514 int nArg, 5515 int eTextRep, 5516 void *pApp, 5517 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5518 void (*xFinal)(sqlite3_context*), 5519 void (*xValue)(sqlite3_context*), 5520 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5521 void(*xDestroy)(void*) 5522 ); 5523 5524 /* 5525 ** CAPI3REF: Text Encodings 5526 ** 5527 ** These constant define integer codes that represent the various 5528 ** text encodings supported by SQLite. 5529 */ 5530 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5531 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5532 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5533 #define SQLITE_UTF16 4 /* Use native byte order */ 5534 #define SQLITE_ANY 5 /* Deprecated */ 5535 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5536 5537 /* 5538 ** CAPI3REF: Function Flags 5539 ** 5540 ** These constants may be ORed together with the 5541 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5542 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5543 ** [sqlite3_create_function_v2()]. 5544 ** 5545 ** <dl> 5546 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5547 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5548 ** the same output when the input parameters are the same. 5549 ** The [abs|abs() function] is deterministic, for example, but 5550 ** [randomblob|randomblob()] is not. Functions must 5551 ** be deterministic in order to be used in certain contexts such as 5552 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5553 ** SQLite might also optimize deterministic functions by factoring them 5554 ** out of inner loops. 5555 ** </dd> 5556 ** 5557 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5558 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5559 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5560 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5561 ** [expression indexes], [partial indexes], or [generated columns]. 5562 ** <p> 5563 ** The SQLITE_DIRECTONLY flag is recommended for any 5564 ** [application-defined SQL function] 5565 ** that has side-effects or that could potentially leak sensitive information. 5566 ** This will prevent attacks in which an application is tricked 5567 ** into using a database file that has had its schema surreptitiously 5568 ** modified to invoke the application-defined function in ways that are 5569 ** harmful. 5570 ** <p> 5571 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all 5572 ** [application-defined SQL functions], regardless of whether or not they 5573 ** are security sensitive, as doing so prevents those functions from being used 5574 ** inside of the database schema, and thus ensures that the database 5575 ** can be inspected and modified using generic tools (such as the [CLI]) 5576 ** that do not have access to the application-defined functions. 5577 ** </dd> 5578 ** 5579 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5580 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5581 ** to cause problems even if misused. An innocuous function should have 5582 ** no side effects and should not depend on any values other than its 5583 ** input parameters. The [abs|abs() function] is an example of an 5584 ** innocuous function. 5585 ** The [load_extension() SQL function] is not innocuous because of its 5586 ** side effects. 5587 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5588 ** exactly the same. The [random|random() function] is an example of a 5589 ** function that is innocuous but not deterministic. 5590 ** <p>Some heightened security settings 5591 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5592 ** disable the use of SQL functions inside views and triggers and in 5593 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5594 ** [expression indexes], [partial indexes], and [generated columns] unless 5595 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5596 ** are innocuous. Developers are advised to avoid using the 5597 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5598 ** function has been carefully audited and found to be free of potentially 5599 ** security-adverse side-effects and information-leaks. 5600 ** </dd> 5601 ** 5602 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5603 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call 5604 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5605 ** This flag instructs SQLite to omit some corner-case optimizations that 5606 ** might disrupt the operation of the [sqlite3_value_subtype()] function, 5607 ** causing it to return zero rather than the correct subtype(). 5608 ** SQL functions that invokes [sqlite3_value_subtype()] should have this 5609 ** property. If the SQLITE_SUBTYPE property is omitted, then the return 5610 ** value from [sqlite3_value_subtype()] might sometimes be zero even though 5611 ** a non-zero subtype was specified by the function argument expression. 5612 ** 5613 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd> 5614 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call 5615 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its 5616 ** result. 5617 ** Every function that invokes [sqlite3_result_subtype()] should have this 5618 ** property. If it does not, then the call to [sqlite3_result_subtype()] 5619 ** might become a no-op if the function is used as term in an 5620 ** [expression index]. On the other hand, SQL functions that never invoke 5621 ** [sqlite3_result_subtype()] should avoid setting this property, as the 5622 ** purpose of this property is to disable certain optimizations that are 5623 ** incompatible with subtypes. 5624 ** </dd> 5625 ** </dl> 5626 */ 5627 #define SQLITE_DETERMINISTIC 0x000000800 5628 #define SQLITE_DIRECTONLY 0x000080000 5629 #define SQLITE_SUBTYPE 0x000100000 5630 #define SQLITE_INNOCUOUS 0x000200000 5631 #define SQLITE_RESULT_SUBTYPE 0x001000000 5632 5633 /* 5634 ** CAPI3REF: Deprecated Functions 5635 ** DEPRECATED 5636 ** 5637 ** These functions are [deprecated]. In order to maintain 5638 ** backwards compatibility with older code, these functions continue 5639 ** to be supported. However, new applications should avoid 5640 ** the use of these functions. To encourage programmers to avoid 5641 ** these functions, we will not explain what they do. 5642 */ 5643 #ifndef SQLITE_OMIT_DEPRECATED 5644 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5645 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5646 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5647 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5648 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5649 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5650 void*,sqlite3_int64); 5651 #endif 5652 5653 /* 5654 ** CAPI3REF: Obtaining SQL Values 5655 ** METHOD: sqlite3_value 5656 ** 5657 ** <b>Summary:</b> 5658 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5659 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5660 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5661 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5662 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5663 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5664 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5665 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5666 ** the native byteorder 5667 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5668 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5669 ** <tr><td> <td> <td> 5670 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5671 ** or a UTF-8 TEXT in bytes 5672 ** <tr><td><b>sqlite3_value_bytes16 </b> 5673 ** <td>→ <td>Size of UTF-16 5674 ** TEXT in bytes 5675 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5676 ** datatype of the value 5677 ** <tr><td><b>sqlite3_value_numeric_type </b> 5678 ** <td>→ <td>Best numeric datatype of the value 5679 ** <tr><td><b>sqlite3_value_nochange </b> 5680 ** <td>→ <td>True if the column is unchanged in an UPDATE 5681 ** against a virtual table. 5682 ** <tr><td><b>sqlite3_value_frombind </b> 5683 ** <td>→ <td>True if value originated from a [bound parameter] 5684 ** </table></blockquote> 5685 ** 5686 ** <b>Details:</b> 5687 ** 5688 ** These routines extract type, size, and content information from 5689 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5690 ** are used to pass parameter information into the functions that 5691 ** implement [application-defined SQL functions] and [virtual tables]. 5692 ** 5693 ** These routines work only with [protected sqlite3_value] objects. 5694 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5695 ** is not threadsafe. 5696 ** 5697 ** ^These routines work just like the corresponding [column access functions] 5698 ** except that these routines take a single [protected sqlite3_value] object 5699 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5700 ** 5701 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5702 ** in the native byte-order of the host machine. ^The 5703 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5704 ** extract UTF-16 strings as big-endian and little-endian respectively. 5705 ** 5706 ** ^If [sqlite3_value] object V was initialized 5707 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5708 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5709 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5710 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5711 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5712 ** 5713 ** ^(The sqlite3_value_type(V) interface returns the 5714 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5715 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5716 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5717 ** Other interfaces might change the datatype for an sqlite3_value object. 5718 ** For example, if the datatype is initially SQLITE_INTEGER and 5719 ** sqlite3_value_text(V) is called to extract a text value for that 5720 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5721 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5722 ** occurs is undefined and may change from one release of SQLite to the next. 5723 ** 5724 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5725 ** numeric affinity to the value. This means that an attempt is 5726 ** made to convert the value to an integer or floating point. If 5727 ** such a conversion is possible without loss of information (in other 5728 ** words, if the value is a string that looks like a number) 5729 ** then the conversion is performed. Otherwise no conversion occurs. 5730 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5731 ** 5732 ** ^Within the [xUpdate] method of a [virtual table], the 5733 ** sqlite3_value_nochange(X) interface returns true if and only if 5734 ** the column corresponding to X is unchanged by the UPDATE operation 5735 ** that the xUpdate method call was invoked to implement and if 5736 ** and the prior [xColumn] method call that was invoked to extracted 5737 ** the value for that column returned without setting a result (probably 5738 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5739 ** was unchanging). ^Within an [xUpdate] method, any value for which 5740 ** sqlite3_value_nochange(X) is true will in all other respects appear 5741 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5742 ** than within an [xUpdate] method call for an UPDATE statement, then 5743 ** the return value is arbitrary and meaningless. 5744 ** 5745 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5746 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5747 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5748 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5749 ** 5750 ** Please pay particular attention to the fact that the pointer returned 5751 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5752 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5753 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5754 ** or [sqlite3_value_text16()]. 5755 ** 5756 ** These routines must be called from the same thread as 5757 ** the SQL function that supplied the [sqlite3_value*] parameters. 5758 ** 5759 ** As long as the input parameter is correct, these routines can only 5760 ** fail if an out-of-memory error occurs during a format conversion. 5761 ** Only the following subset of interfaces are subject to out-of-memory 5762 ** errors: 5763 ** 5764 ** <ul> 5765 ** <li> sqlite3_value_blob() 5766 ** <li> sqlite3_value_text() 5767 ** <li> sqlite3_value_text16() 5768 ** <li> sqlite3_value_text16le() 5769 ** <li> sqlite3_value_text16be() 5770 ** <li> sqlite3_value_bytes() 5771 ** <li> sqlite3_value_bytes16() 5772 ** </ul> 5773 ** 5774 ** If an out-of-memory error occurs, then the return value from these 5775 ** routines is the same as if the column had contained an SQL NULL value. 5776 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5777 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5778 ** return value is obtained and before any 5779 ** other SQLite interface is called on the same [database connection]. 5780 */ 5781 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5782 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5783 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5784 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5785 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5786 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5787 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5788 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5789 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5790 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5791 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5792 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5793 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5794 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5795 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5796 5797 /* 5798 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object 5799 ** METHOD: sqlite3_value 5800 ** 5801 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5802 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding 5803 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5804 ** returns something other than SQLITE_TEXT, then the return value from 5805 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 5806 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)], 5807 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or 5808 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and 5809 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5810 ** 5811 ** This routine is intended for used by applications that test and validate 5812 ** the SQLite implementation. This routine is inquiring about the opaque 5813 ** internal state of an [sqlite3_value] object. Ordinary applications should 5814 ** not need to know what the internal state of an sqlite3_value object is and 5815 ** hence should not need to use this interface. 5816 */ 5817 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5818 5819 /* 5820 ** CAPI3REF: Finding The Subtype Of SQL Values 5821 ** METHOD: sqlite3_value 5822 ** 5823 ** The sqlite3_value_subtype(V) function returns the subtype for 5824 ** an [application-defined SQL function] argument V. The subtype 5825 ** information can be used to pass a limited amount of context from 5826 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5827 ** routine to set the subtype for the return value of an SQL function. 5828 ** 5829 ** Every [application-defined SQL function] that invoke this interface 5830 ** should include the [SQLITE_SUBTYPE] property in the text 5831 ** encoding argument when the function is [sqlite3_create_function|registered]. 5832 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype() 5833 ** might return zero instead of the upstream subtype in some corner cases. 5834 */ 5835 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5836 5837 /* 5838 ** CAPI3REF: Copy And Free SQL Values 5839 ** METHOD: sqlite3_value 5840 ** 5841 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5842 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5843 ** is a [protected sqlite3_value] object even if the input is not. 5844 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5845 ** memory allocation fails. ^If V is a [pointer value], then the result 5846 ** of sqlite3_value_dup(V) is a NULL value. 5847 ** 5848 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5849 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5850 ** then sqlite3_value_free(V) is a harmless no-op. 5851 */ 5852 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5853 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5854 5855 /* 5856 ** CAPI3REF: Obtain Aggregate Function Context 5857 ** METHOD: sqlite3_context 5858 ** 5859 ** Implementations of aggregate SQL functions use this 5860 ** routine to allocate memory for storing their state. 5861 ** 5862 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5863 ** for a particular aggregate function, SQLite allocates 5864 ** N bytes of memory, zeroes out that memory, and returns a pointer 5865 ** to the new memory. ^On second and subsequent calls to 5866 ** sqlite3_aggregate_context() for the same aggregate function instance, 5867 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5868 ** called once for each invocation of the xStep callback and then one 5869 ** last time when the xFinal callback is invoked. ^(When no rows match 5870 ** an aggregate query, the xStep() callback of the aggregate function 5871 ** implementation is never called and xFinal() is called exactly once. 5872 ** In those cases, sqlite3_aggregate_context() might be called for the 5873 ** first time from within xFinal().)^ 5874 ** 5875 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5876 ** when first called if N is less than or equal to zero or if a memory 5877 ** allocation error occurs. 5878 ** 5879 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5880 ** determined by the N parameter on first successful call. Changing the 5881 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5882 ** the same aggregate function instance will not resize the memory 5883 ** allocation.)^ Within the xFinal callback, it is customary to set 5884 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5885 ** pointless memory allocations occur. 5886 ** 5887 ** ^SQLite automatically frees the memory allocated by 5888 ** sqlite3_aggregate_context() when the aggregate query concludes. 5889 ** 5890 ** The first parameter must be a copy of the 5891 ** [sqlite3_context | SQL function context] that is the first parameter 5892 ** to the xStep or xFinal callback routine that implements the aggregate 5893 ** function. 5894 ** 5895 ** This routine must be called from the same thread in which 5896 ** the aggregate SQL function is running. 5897 */ 5898 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5899 5900 /* 5901 ** CAPI3REF: User Data For Functions 5902 ** METHOD: sqlite3_context 5903 ** 5904 ** ^The sqlite3_user_data() interface returns a copy of 5905 ** the pointer that was the pUserData parameter (the 5th parameter) 5906 ** of the [sqlite3_create_function()] 5907 ** and [sqlite3_create_function16()] routines that originally 5908 ** registered the application defined function. 5909 ** 5910 ** This routine must be called from the same thread in which 5911 ** the application-defined function is running. 5912 */ 5913 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5914 5915 /* 5916 ** CAPI3REF: Database Connection For Functions 5917 ** METHOD: sqlite3_context 5918 ** 5919 ** ^The sqlite3_context_db_handle() interface returns a copy of 5920 ** the pointer to the [database connection] (the 1st parameter) 5921 ** of the [sqlite3_create_function()] 5922 ** and [sqlite3_create_function16()] routines that originally 5923 ** registered the application defined function. 5924 */ 5925 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5926 5927 /* 5928 ** CAPI3REF: Function Auxiliary Data 5929 ** METHOD: sqlite3_context 5930 ** 5931 ** These functions may be used by (non-aggregate) SQL functions to 5932 ** associate auxiliary data with argument values. If the same argument 5933 ** value is passed to multiple invocations of the same SQL function during 5934 ** query execution, under some circumstances the associated auxiliary data 5935 ** might be preserved. An example of where this might be useful is in a 5936 ** regular-expression matching function. The compiled version of the regular 5937 ** expression can be stored as auxiliary data associated with the pattern string. 5938 ** Then as long as the pattern string remains the same, 5939 ** the compiled regular expression can be reused on multiple 5940 ** invocations of the same function. 5941 ** 5942 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data 5943 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5944 ** value to the application-defined function. ^N is zero for the left-most 5945 ** function argument. ^If there is no auxiliary data 5946 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5947 ** returns a NULL pointer. 5948 ** 5949 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the 5950 ** N-th argument of the application-defined function. ^Subsequent 5951 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5952 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or 5953 ** NULL if the auxiliary data has been discarded. 5954 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5955 ** SQLite will invoke the destructor function X with parameter P exactly 5956 ** once, when the auxiliary data is discarded. 5957 ** SQLite is free to discard the auxiliary data at any time, including: <ul> 5958 ** <li> ^(when the corresponding function parameter changes)^, or 5959 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5960 ** SQL statement)^, or 5961 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5962 ** parameter)^, or 5963 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5964 ** allocation error occurs.)^ 5965 ** <li> ^(during the original sqlite3_set_auxdata() call if the function 5966 ** is evaluated during query planning instead of during query execution, 5967 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul> 5968 ** 5969 ** Note the last two bullets in particular. The destructor X in 5970 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5971 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5972 ** should be called near the end of the function implementation and the 5973 ** function implementation should not make any use of P after 5974 ** sqlite3_set_auxdata() has been called. Furthermore, a call to 5975 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call 5976 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory 5977 ** condition occurred during the sqlite3_set_auxdata() call or if the 5978 ** function is being evaluated during query planning rather than during 5979 ** query execution. 5980 ** 5981 ** ^(In practice, auxiliary data is preserved between function calls for 5982 ** function parameters that are compile-time constants, including literal 5983 ** values and [parameters] and expressions composed from the same.)^ 5984 ** 5985 ** The value of the N parameter to these interfaces should be non-negative. 5986 ** Future enhancements may make use of negative N values to define new 5987 ** kinds of function caching behavior. 5988 ** 5989 ** These routines must be called from the same thread in which 5990 ** the SQL function is running. 5991 ** 5992 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()]. 5993 */ 5994 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5995 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5996 5997 /* 5998 ** CAPI3REF: Database Connection Client Data 5999 ** METHOD: sqlite3 6000 ** 6001 ** These functions are used to associate one or more named pointers 6002 ** with a [database connection]. 6003 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P 6004 ** to be attached to [database connection] D using name N. Subsequent 6005 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P 6006 ** or a NULL pointer if there were no prior calls to 6007 ** sqlite3_set_clientdata() with the same values of D and N. 6008 ** Names are compared using strcmp() and are thus case sensitive. 6009 ** 6010 ** If P and X are both non-NULL, then the destructor X is invoked with 6011 ** argument P on the first of the following occurrences: 6012 ** <ul> 6013 ** <li> An out-of-memory error occurs during the call to 6014 ** sqlite3_set_clientdata() which attempts to register pointer P. 6015 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made 6016 ** with the same D and N parameters. 6017 ** <li> The database connection closes. SQLite does not make any guarantees 6018 ** about the order in which destructors are called, only that all 6019 ** destructors will be called exactly once at some point during the 6020 ** database connection closing process. 6021 ** </ul> 6022 ** 6023 ** SQLite does not do anything with client data other than invoke 6024 ** destructors on the client data at the appropriate time. The intended 6025 ** use for client data is to provide a mechanism for wrapper libraries 6026 ** to store additional information about an SQLite database connection. 6027 ** 6028 ** There is no limit (other than available memory) on the number of different 6029 ** client data pointers (with different names) that can be attached to a 6030 ** single database connection. However, the implementation is optimized 6031 ** for the case of having only one or two different client data names. 6032 ** Applications and wrapper libraries are discouraged from using more than 6033 ** one client data name each. 6034 ** 6035 ** There is no way to enumerate the client data pointers 6036 ** associated with a database connection. The N parameter can be thought 6037 ** of as a secret key such that only code that knows the secret key is able 6038 ** to access the associated data. 6039 ** 6040 ** Security Warning: These interfaces should not be exposed in scripting 6041 ** languages or in other circumstances where it might be possible for an 6042 ** an attacker to invoke them. Any agent that can invoke these interfaces 6043 ** can probably also take control of the process. 6044 ** 6045 ** Database connection client data is only available for SQLite 6046 ** version 3.44.0 ([dateof:3.44.0]) and later. 6047 ** 6048 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()]. 6049 */ 6050 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*); 6051 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*)); 6052 6053 /* 6054 ** CAPI3REF: Constants Defining Special Destructor Behavior 6055 ** 6056 ** These are special values for the destructor that is passed in as the 6057 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 6058 ** argument is SQLITE_STATIC, it means that the content pointer is constant 6059 ** and will never change. It does not need to be destroyed. ^The 6060 ** SQLITE_TRANSIENT value means that the content will likely change in 6061 ** the near future and that SQLite should make its own private copy of 6062 ** the content before returning. 6063 ** 6064 ** The typedef is necessary to work around problems in certain 6065 ** C++ compilers. 6066 */ 6067 typedef void (*sqlite3_destructor_type)(void*); 6068 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 6069 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 6070 6071 /* 6072 ** CAPI3REF: Setting The Result Of An SQL Function 6073 ** METHOD: sqlite3_context 6074 ** 6075 ** These routines are used by the xFunc or xFinal callbacks that 6076 ** implement SQL functions and aggregates. See 6077 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 6078 ** for additional information. 6079 ** 6080 ** These functions work very much like the [parameter binding] family of 6081 ** functions used to bind values to host parameters in prepared statements. 6082 ** Refer to the [SQL parameter] documentation for additional information. 6083 ** 6084 ** ^The sqlite3_result_blob() interface sets the result from 6085 ** an application-defined function to be the BLOB whose content is pointed 6086 ** to by the second parameter and which is N bytes long where N is the 6087 ** third parameter. 6088 ** 6089 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 6090 ** interfaces set the result of the application-defined function to be 6091 ** a BLOB containing all zero bytes and N bytes in size. 6092 ** 6093 ** ^The sqlite3_result_double() interface sets the result from 6094 ** an application-defined function to be a floating point value specified 6095 ** by its 2nd argument. 6096 ** 6097 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 6098 ** cause the implemented SQL function to throw an exception. 6099 ** ^SQLite uses the string pointed to by the 6100 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 6101 ** as the text of an error message. ^SQLite interprets the error 6102 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 6103 ** interprets the string from sqlite3_result_error16() as UTF-16 using 6104 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 6105 ** ^If the third parameter to sqlite3_result_error() 6106 ** or sqlite3_result_error16() is negative then SQLite takes as the error 6107 ** message all text up through the first zero character. 6108 ** ^If the third parameter to sqlite3_result_error() or 6109 ** sqlite3_result_error16() is non-negative then SQLite takes that many 6110 ** bytes (not characters) from the 2nd parameter as the error message. 6111 ** ^The sqlite3_result_error() and sqlite3_result_error16() 6112 ** routines make a private copy of the error message text before 6113 ** they return. Hence, the calling function can deallocate or 6114 ** modify the text after they return without harm. 6115 ** ^The sqlite3_result_error_code() function changes the error code 6116 ** returned by SQLite as a result of an error in a function. ^By default, 6117 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 6118 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 6119 ** 6120 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 6121 ** error indicating that a string or BLOB is too long to represent. 6122 ** 6123 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 6124 ** error indicating that a memory allocation failed. 6125 ** 6126 ** ^The sqlite3_result_int() interface sets the return value 6127 ** of the application-defined function to be the 32-bit signed integer 6128 ** value given in the 2nd argument. 6129 ** ^The sqlite3_result_int64() interface sets the return value 6130 ** of the application-defined function to be the 64-bit signed integer 6131 ** value given in the 2nd argument. 6132 ** 6133 ** ^The sqlite3_result_null() interface sets the return value 6134 ** of the application-defined function to be NULL. 6135 ** 6136 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 6137 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 6138 ** set the return value of the application-defined function to be 6139 ** a text string which is represented as UTF-8, UTF-16 native byte order, 6140 ** UTF-16 little endian, or UTF-16 big endian, respectively. 6141 ** ^The sqlite3_result_text64() interface sets the return value of an 6142 ** application-defined function to be a text string in an encoding 6143 ** specified by the fifth (and last) parameter, which must be one 6144 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 6145 ** ^SQLite takes the text result from the application from 6146 ** the 2nd parameter of the sqlite3_result_text* interfaces. 6147 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 6148 ** other than sqlite3_result_text64() is negative, then SQLite computes 6149 ** the string length itself by searching the 2nd parameter for the first 6150 ** zero character. 6151 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 6152 ** is non-negative, then as many bytes (not characters) of the text 6153 ** pointed to by the 2nd parameter are taken as the application-defined 6154 ** function result. If the 3rd parameter is non-negative, then it 6155 ** must be the byte offset into the string where the NUL terminator would 6156 ** appear if the string where NUL terminated. If any NUL characters occur 6157 ** in the string at a byte offset that is less than the value of the 3rd 6158 ** parameter, then the resulting string will contain embedded NULs and the 6159 ** result of expressions operating on strings with embedded NULs is undefined. 6160 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6161 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 6162 ** function as the destructor on the text or BLOB result when it has 6163 ** finished using that result. 6164 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 6165 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 6166 ** assumes that the text or BLOB result is in constant space and does not 6167 ** copy the content of the parameter nor call a destructor on the content 6168 ** when it has finished using that result. 6169 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 6170 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 6171 ** then SQLite makes a copy of the result into space obtained 6172 ** from [sqlite3_malloc()] before it returns. 6173 ** 6174 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 6175 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 6176 ** when the encoding is not UTF8, if the input UTF16 begins with a 6177 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 6178 ** string and the rest of the string is interpreted according to the 6179 ** byte-order specified by the BOM. ^The byte-order specified by 6180 ** the BOM at the beginning of the text overrides the byte-order 6181 ** specified by the interface procedure. ^So, for example, if 6182 ** sqlite3_result_text16le() is invoked with text that begins 6183 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 6184 ** first two bytes of input are skipped and the remaining input 6185 ** is interpreted as UTF16BE text. 6186 ** 6187 ** ^For UTF16 input text to the sqlite3_result_text16(), 6188 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 6189 ** sqlite3_result_text64() routines, if the text contains invalid 6190 ** UTF16 characters, the invalid characters might be converted 6191 ** into the unicode replacement character, U+FFFD. 6192 ** 6193 ** ^The sqlite3_result_value() interface sets the result of 6194 ** the application-defined function to be a copy of the 6195 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 6196 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 6197 ** so that the [sqlite3_value] specified in the parameter may change or 6198 ** be deallocated after sqlite3_result_value() returns without harm. 6199 ** ^A [protected sqlite3_value] object may always be used where an 6200 ** [unprotected sqlite3_value] object is required, so either 6201 ** kind of [sqlite3_value] object can be used with this interface. 6202 ** 6203 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 6204 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 6205 ** also associates the host-language pointer P or type T with that 6206 ** NULL value such that the pointer can be retrieved within an 6207 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 6208 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 6209 ** for the P parameter. ^SQLite invokes D with P as its only argument 6210 ** when SQLite is finished with P. The T parameter should be a static 6211 ** string and preferably a string literal. The sqlite3_result_pointer() 6212 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 6213 ** 6214 ** If these routines are called from within the different thread 6215 ** than the one containing the application-defined function that received 6216 ** the [sqlite3_context] pointer, the results are undefined. 6217 */ 6218 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 6219 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 6220 sqlite3_uint64,void(*)(void*)); 6221 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 6222 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 6223 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 6224 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 6225 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 6226 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 6227 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 6228 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 6229 SQLITE_API void sqlite3_result_null(sqlite3_context*); 6230 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 6231 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 6232 void(*)(void*), unsigned char encoding); 6233 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 6234 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 6235 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 6236 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 6237 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6238 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6239 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6240 6241 6242 /* 6243 ** CAPI3REF: Setting The Subtype Of An SQL Function 6244 ** METHOD: sqlite3_context 6245 ** 6246 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6247 ** the result from the [application-defined SQL function] with 6248 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6249 ** of the subtype T are preserved in current versions of SQLite; 6250 ** higher order bits are discarded. 6251 ** The number of subtype bytes preserved by SQLite might increase 6252 ** in future releases of SQLite. 6253 ** 6254 ** Every [application-defined SQL function] that invokes this interface 6255 ** should include the [SQLITE_RESULT_SUBTYPE] property in its 6256 ** text encoding argument when the SQL function is 6257 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE] 6258 ** property is omitted from the function that invokes sqlite3_result_subtype(), 6259 ** then in some cases the sqlite3_result_subtype() might fail to set 6260 ** the result subtype. 6261 ** 6262 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any 6263 ** SQL function that invokes the sqlite3_result_subtype() interface 6264 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise 6265 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1 6266 ** by default. 6267 */ 6268 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6269 6270 /* 6271 ** CAPI3REF: Define New Collating Sequences 6272 ** METHOD: sqlite3 6273 ** 6274 ** ^These functions add, remove, or modify a [collation] associated 6275 ** with the [database connection] specified as the first argument. 6276 ** 6277 ** ^The name of the collation is a UTF-8 string 6278 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6279 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6280 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6281 ** considered to be the same name. 6282 ** 6283 ** ^(The third argument (eTextRep) must be one of the constants: 6284 ** <ul> 6285 ** <li> [SQLITE_UTF8], 6286 ** <li> [SQLITE_UTF16LE], 6287 ** <li> [SQLITE_UTF16BE], 6288 ** <li> [SQLITE_UTF16], or 6289 ** <li> [SQLITE_UTF16_ALIGNED]. 6290 ** </ul>)^ 6291 ** ^The eTextRep argument determines the encoding of strings passed 6292 ** to the collating function callback, xCompare. 6293 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6294 ** force strings to be UTF16 with native byte order. 6295 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6296 ** on an even byte address. 6297 ** 6298 ** ^The fourth argument, pArg, is an application data pointer that is passed 6299 ** through as the first argument to the collating function callback. 6300 ** 6301 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6302 ** ^Multiple collating functions can be registered using the same name but 6303 ** with different eTextRep parameters and SQLite will use whichever 6304 ** function requires the least amount of data transformation. 6305 ** ^If the xCompare argument is NULL then the collating function is 6306 ** deleted. ^When all collating functions having the same name are deleted, 6307 ** that collation is no longer usable. 6308 ** 6309 ** ^The collating function callback is invoked with a copy of the pArg 6310 ** application data pointer and with two strings in the encoding specified 6311 ** by the eTextRep argument. The two integer parameters to the collating 6312 ** function callback are the length of the two strings, in bytes. The collating 6313 ** function must return an integer that is negative, zero, or positive 6314 ** if the first string is less than, equal to, or greater than the second, 6315 ** respectively. A collating function must always return the same answer 6316 ** given the same inputs. If two or more collating functions are registered 6317 ** to the same collation name (using different eTextRep values) then all 6318 ** must give an equivalent answer when invoked with equivalent strings. 6319 ** The collating function must obey the following properties for all 6320 ** strings A, B, and C: 6321 ** 6322 ** <ol> 6323 ** <li> If A==B then B==A. 6324 ** <li> If A==B and B==C then A==C. 6325 ** <li> If A<B THEN B>A. 6326 ** <li> If A<B and B<C then A<C. 6327 ** </ol> 6328 ** 6329 ** If a collating function fails any of the above constraints and that 6330 ** collating function is registered and used, then the behavior of SQLite 6331 ** is undefined. 6332 ** 6333 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6334 ** with the addition that the xDestroy callback is invoked on pArg when 6335 ** the collating function is deleted. 6336 ** ^Collating functions are deleted when they are overridden by later 6337 ** calls to the collation creation functions or when the 6338 ** [database connection] is closed using [sqlite3_close()]. 6339 ** 6340 ** ^The xDestroy callback is <u>not</u> called if the 6341 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6342 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6343 ** check the return code and dispose of the application data pointer 6344 ** themselves rather than expecting SQLite to deal with it for them. 6345 ** This is different from every other SQLite interface. The inconsistency 6346 ** is unfortunate but cannot be changed without breaking backwards 6347 ** compatibility. 6348 ** 6349 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6350 */ 6351 SQLITE_API int sqlite3_create_collation( 6352 sqlite3*, 6353 const char *zName, 6354 int eTextRep, 6355 void *pArg, 6356 int(*xCompare)(void*,int,const void*,int,const void*) 6357 ); 6358 SQLITE_API int sqlite3_create_collation_v2( 6359 sqlite3*, 6360 const char *zName, 6361 int eTextRep, 6362 void *pArg, 6363 int(*xCompare)(void*,int,const void*,int,const void*), 6364 void(*xDestroy)(void*) 6365 ); 6366 SQLITE_API int sqlite3_create_collation16( 6367 sqlite3*, 6368 const void *zName, 6369 int eTextRep, 6370 void *pArg, 6371 int(*xCompare)(void*,int,const void*,int,const void*) 6372 ); 6373 6374 /* 6375 ** CAPI3REF: Collation Needed Callbacks 6376 ** METHOD: sqlite3 6377 ** 6378 ** ^To avoid having to register all collation sequences before a database 6379 ** can be used, a single callback function may be registered with the 6380 ** [database connection] to be invoked whenever an undefined collation 6381 ** sequence is required. 6382 ** 6383 ** ^If the function is registered using the sqlite3_collation_needed() API, 6384 ** then it is passed the names of undefined collation sequences as strings 6385 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6386 ** the names are passed as UTF-16 in machine native byte order. 6387 ** ^A call to either function replaces the existing collation-needed callback. 6388 ** 6389 ** ^(When the callback is invoked, the first argument passed is a copy 6390 ** of the second argument to sqlite3_collation_needed() or 6391 ** sqlite3_collation_needed16(). The second argument is the database 6392 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6393 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6394 ** sequence function required. The fourth parameter is the name of the 6395 ** required collation sequence.)^ 6396 ** 6397 ** The callback function should register the desired collation using 6398 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6399 ** [sqlite3_create_collation_v2()]. 6400 */ 6401 SQLITE_API int sqlite3_collation_needed( 6402 sqlite3*, 6403 void*, 6404 void(*)(void*,sqlite3*,int eTextRep,const char*) 6405 ); 6406 SQLITE_API int sqlite3_collation_needed16( 6407 sqlite3*, 6408 void*, 6409 void(*)(void*,sqlite3*,int eTextRep,const void*) 6410 ); 6411 6412 #ifdef SQLITE_HAS_CODEC 6413 /* 6414 ** Specify the key for an encrypted database. This routine should be 6415 ** called right after sqlite3_open(). 6416 ** 6417 ** The code to implement this API is not available in the public release 6418 ** of SQLite. 6419 */ 6420 SQLITE_API int sqlite3_key( 6421 sqlite3 *db, /* Database to be rekeyed */ 6422 const void *pKey, int nKey /* The key */ 6423 ); 6424 SQLITE_API int sqlite3_key_v2( 6425 sqlite3 *db, /* Database to be rekeyed */ 6426 const char *zDbName, /* Name of the database */ 6427 const void *pKey, int nKey /* The key */ 6428 ); 6429 6430 /* 6431 ** Change the key on an open database. If the current database is not 6432 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 6433 ** database is decrypted. 6434 ** 6435 ** The code to implement this API is not available in the public release 6436 ** of SQLite. 6437 */ 6438 SQLITE_API int sqlite3_rekey( 6439 sqlite3 *db, /* Database to be rekeyed */ 6440 const void *pKey, int nKey /* The new key */ 6441 ); 6442 SQLITE_API int sqlite3_rekey_v2( 6443 sqlite3 *db, /* Database to be rekeyed */ 6444 const char *zDbName, /* Name of the database */ 6445 const void *pKey, int nKey /* The new key */ 6446 ); 6447 6448 #endif 6449 6450 #ifdef SQLITE_ENABLE_CEROD 6451 /* 6452 ** Specify the activation key for a CEROD database. Unless 6453 ** activated, none of the CEROD routines will work. 6454 */ 6455 SQLITE_API void sqlite3_activate_cerod( 6456 const char *zPassPhrase /* Activation phrase */ 6457 ); 6458 #endif 6459 6460 /* 6461 ** CAPI3REF: Suspend Execution For A Short Time 6462 ** 6463 ** The sqlite3_sleep() function causes the current thread to suspend execution 6464 ** for at least a number of milliseconds specified in its parameter. 6465 ** 6466 ** If the operating system does not support sleep requests with 6467 ** millisecond time resolution, then the time will be rounded up to 6468 ** the nearest second. The number of milliseconds of sleep actually 6469 ** requested from the operating system is returned. 6470 ** 6471 ** ^SQLite implements this interface by calling the xSleep() 6472 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6473 ** of the default VFS is not implemented correctly, or not implemented at 6474 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6475 ** in the previous paragraphs. 6476 ** 6477 ** If a negative argument is passed to sqlite3_sleep() the results vary by 6478 ** VFS and operating system. Some system treat a negative argument as an 6479 ** instruction to sleep forever. Others understand it to mean do not sleep 6480 ** at all. ^In SQLite version 3.42.0 and later, a negative 6481 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed 6482 ** down into the xSleep method of the VFS. 6483 */ 6484 SQLITE_API int sqlite3_sleep(int); 6485 6486 /* 6487 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6488 ** 6489 ** ^(If this global variable is made to point to a string which is 6490 ** the name of a folder (a.k.a. directory), then all temporary files 6491 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6492 ** will be placed in that directory.)^ ^If this variable 6493 ** is a NULL pointer, then SQLite performs a search for an appropriate 6494 ** temporary file directory. 6495 ** 6496 ** Applications are strongly discouraged from using this global variable. 6497 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6498 ** But for all other platforms, it is highly recommended that applications 6499 ** neither read nor write this variable. This global variable is a relic 6500 ** that exists for backwards compatibility of legacy applications and should 6501 ** be avoided in new projects. 6502 ** 6503 ** It is not safe to read or modify this variable in more than one 6504 ** thread at a time. It is not safe to read or modify this variable 6505 ** if a [database connection] is being used at the same time in a separate 6506 ** thread. 6507 ** It is intended that this variable be set once 6508 ** as part of process initialization and before any SQLite interface 6509 ** routines have been called and that this variable remain unchanged 6510 ** thereafter. 6511 ** 6512 ** ^The [temp_store_directory pragma] may modify this variable and cause 6513 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6514 ** the [temp_store_directory pragma] always assumes that any string 6515 ** that this variable points to is held in memory obtained from 6516 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6517 ** using [sqlite3_free]. 6518 ** Hence, if this variable is modified directly, either it should be 6519 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6520 ** or else the use of the [temp_store_directory pragma] should be avoided. 6521 ** Except when requested by the [temp_store_directory pragma], SQLite 6522 ** does not free the memory that sqlite3_temp_directory points to. If 6523 ** the application wants that memory to be freed, it must do 6524 ** so itself, taking care to only do so after all [database connection] 6525 ** objects have been destroyed. 6526 ** 6527 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6528 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6529 ** features that require the use of temporary files may fail. Here is an 6530 ** example of how to do this using C++ with the Windows Runtime: 6531 ** 6532 ** <blockquote><pre> 6533 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6534 ** TemporaryFolder->Path->Data(); 6535 ** char zPathBuf[MAX_PATH + 1]; 6536 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6537 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6538 ** NULL, NULL); 6539 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6540 ** </pre></blockquote> 6541 */ 6542 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6543 6544 /* 6545 ** CAPI3REF: Name Of The Folder Holding Database Files 6546 ** 6547 ** ^(If this global variable is made to point to a string which is 6548 ** the name of a folder (a.k.a. directory), then all database files 6549 ** specified with a relative pathname and created or accessed by 6550 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6551 ** to be relative to that directory.)^ ^If this variable is a NULL 6552 ** pointer, then SQLite assumes that all database files specified 6553 ** with a relative pathname are relative to the current directory 6554 ** for the process. Only the windows VFS makes use of this global 6555 ** variable; it is ignored by the unix VFS. 6556 ** 6557 ** Changing the value of this variable while a database connection is 6558 ** open can result in a corrupt database. 6559 ** 6560 ** It is not safe to read or modify this variable in more than one 6561 ** thread at a time. It is not safe to read or modify this variable 6562 ** if a [database connection] is being used at the same time in a separate 6563 ** thread. 6564 ** It is intended that this variable be set once 6565 ** as part of process initialization and before any SQLite interface 6566 ** routines have been called and that this variable remain unchanged 6567 ** thereafter. 6568 ** 6569 ** ^The [data_store_directory pragma] may modify this variable and cause 6570 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6571 ** the [data_store_directory pragma] always assumes that any string 6572 ** that this variable points to is held in memory obtained from 6573 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6574 ** using [sqlite3_free]. 6575 ** Hence, if this variable is modified directly, either it should be 6576 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6577 ** or else the use of the [data_store_directory pragma] should be avoided. 6578 */ 6579 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6580 6581 /* 6582 ** CAPI3REF: Win32 Specific Interface 6583 ** 6584 ** These interfaces are available only on Windows. The 6585 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6586 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6587 ** zValue, depending on the value of the type parameter. The zValue parameter 6588 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6589 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6590 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6591 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6592 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6593 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6594 ** the current directory on the sub-platforms of Win32 where that concept is 6595 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6596 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6597 ** sqlite3_win32_set_directory interface except the string parameter must be 6598 ** UTF-8 or UTF-16, respectively. 6599 */ 6600 SQLITE_API int sqlite3_win32_set_directory( 6601 unsigned long type, /* Identifier for directory being set or reset */ 6602 void *zValue /* New value for directory being set or reset */ 6603 ); 6604 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6605 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6606 6607 /* 6608 ** CAPI3REF: Win32 Directory Types 6609 ** 6610 ** These macros are only available on Windows. They define the allowed values 6611 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6612 */ 6613 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6614 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6615 6616 /* 6617 ** CAPI3REF: Test For Auto-Commit Mode 6618 ** KEYWORDS: {autocommit mode} 6619 ** METHOD: sqlite3 6620 ** 6621 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6622 ** zero if the given database connection is or is not in autocommit mode, 6623 ** respectively. ^Autocommit mode is on by default. 6624 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6625 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6626 ** 6627 ** If certain kinds of errors occur on a statement within a multi-statement 6628 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6629 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6630 ** transaction might be rolled back automatically. The only way to 6631 ** find out whether SQLite automatically rolled back the transaction after 6632 ** an error is to use this function. 6633 ** 6634 ** If another thread changes the autocommit status of the database 6635 ** connection while this routine is running, then the return value 6636 ** is undefined. 6637 */ 6638 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6639 6640 /* 6641 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6642 ** METHOD: sqlite3_stmt 6643 ** 6644 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6645 ** to which a [prepared statement] belongs. ^The [database connection] 6646 ** returned by sqlite3_db_handle is the same [database connection] 6647 ** that was the first argument 6648 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6649 ** create the statement in the first place. 6650 */ 6651 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6652 6653 /* 6654 ** CAPI3REF: Return The Schema Name For A Database Connection 6655 ** METHOD: sqlite3 6656 ** 6657 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6658 ** for the N-th database on database connection D, or a NULL pointer of N is 6659 ** out of range. An N value of 0 means the main database file. An N of 1 is 6660 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6661 ** databases. 6662 ** 6663 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6664 ** by SQLite itself. The string might be deallocated by any operation that 6665 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6666 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6667 ** occur on a different thread. Applications that need to 6668 ** remember the string long-term should make their own copy. Applications that 6669 ** are accessing the same database connection simultaneously on multiple 6670 ** threads should mutex-protect calls to this API and should make their own 6671 ** private copy of the result prior to releasing the mutex. 6672 */ 6673 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6674 6675 /* 6676 ** CAPI3REF: Return The Filename For A Database Connection 6677 ** METHOD: sqlite3 6678 ** 6679 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6680 ** associated with database N of connection D. 6681 ** ^If there is no attached database N on the database 6682 ** connection D, or if database N is a temporary or in-memory database, then 6683 ** this function will return either a NULL pointer or an empty string. 6684 ** 6685 ** ^The string value returned by this routine is owned and managed by 6686 ** the database connection. ^The value will be valid until the database N 6687 ** is [DETACH]-ed or until the database connection closes. 6688 ** 6689 ** ^The filename returned by this function is the output of the 6690 ** xFullPathname method of the [VFS]. ^In other words, the filename 6691 ** will be an absolute pathname, even if the filename used 6692 ** to open the database originally was a URI or relative pathname. 6693 ** 6694 ** If the filename pointer returned by this routine is not NULL, then it 6695 ** can be used as the filename input parameter to these routines: 6696 ** <ul> 6697 ** <li> [sqlite3_uri_parameter()] 6698 ** <li> [sqlite3_uri_boolean()] 6699 ** <li> [sqlite3_uri_int64()] 6700 ** <li> [sqlite3_filename_database()] 6701 ** <li> [sqlite3_filename_journal()] 6702 ** <li> [sqlite3_filename_wal()] 6703 ** </ul> 6704 */ 6705 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6706 6707 /* 6708 ** CAPI3REF: Determine if a database is read-only 6709 ** METHOD: sqlite3 6710 ** 6711 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6712 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6713 ** the name of a database on connection D. 6714 */ 6715 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6716 6717 /* 6718 ** CAPI3REF: Determine the transaction state of a database 6719 ** METHOD: sqlite3 6720 ** 6721 ** ^The sqlite3_txn_state(D,S) interface returns the current 6722 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6723 ** then the highest transaction state of any schema on database connection D 6724 ** is returned. Transaction states are (in order of lowest to highest): 6725 ** <ol> 6726 ** <li value="0"> SQLITE_TXN_NONE 6727 ** <li value="1"> SQLITE_TXN_READ 6728 ** <li value="2"> SQLITE_TXN_WRITE 6729 ** </ol> 6730 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6731 ** a valid schema, then -1 is returned. 6732 */ 6733 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6734 6735 /* 6736 ** CAPI3REF: Allowed return values from sqlite3_txn_state() 6737 ** KEYWORDS: {transaction state} 6738 ** 6739 ** These constants define the current transaction state of a database file. 6740 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6741 ** constants in order to describe the transaction state of schema S 6742 ** in [database connection] D. 6743 ** 6744 ** <dl> 6745 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6746 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6747 ** pending.</dd> 6748 ** 6749 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6750 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6751 ** in a read transaction. Content has been read from the database file 6752 ** but nothing in the database file has changed. The transaction state 6753 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6754 ** no other conflicting concurrent write transactions. The transaction 6755 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6756 ** [COMMIT].</dd> 6757 ** 6758 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6759 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6760 ** in a write transaction. Content has been written to the database file 6761 ** but has not yet committed. The transaction state will change to 6762 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6763 */ 6764 #define SQLITE_TXN_NONE 0 6765 #define SQLITE_TXN_READ 1 6766 #define SQLITE_TXN_WRITE 2 6767 6768 /* 6769 ** CAPI3REF: Find the next prepared statement 6770 ** METHOD: sqlite3 6771 ** 6772 ** ^This interface returns a pointer to the next [prepared statement] after 6773 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6774 ** then this interface returns a pointer to the first prepared statement 6775 ** associated with the database connection pDb. ^If no prepared statement 6776 ** satisfies the conditions of this routine, it returns NULL. 6777 ** 6778 ** The [database connection] pointer D in a call to 6779 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6780 ** connection and in particular must not be a NULL pointer. 6781 */ 6782 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6783 6784 /* 6785 ** CAPI3REF: Commit And Rollback Notification Callbacks 6786 ** METHOD: sqlite3 6787 ** 6788 ** ^The sqlite3_commit_hook() interface registers a callback 6789 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6790 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6791 ** for the same database connection is overridden. 6792 ** ^The sqlite3_rollback_hook() interface registers a callback 6793 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6794 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6795 ** for the same database connection is overridden. 6796 ** ^The pArg argument is passed through to the callback. 6797 ** ^If the callback on a commit hook function returns non-zero, 6798 ** then the commit is converted into a rollback. 6799 ** 6800 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6801 ** return the P argument from the previous call of the same function 6802 ** on the same [database connection] D, or NULL for 6803 ** the first call for each function on D. 6804 ** 6805 ** The commit and rollback hook callbacks are not reentrant. 6806 ** The callback implementation must not do anything that will modify 6807 ** the database connection that invoked the callback. Any actions 6808 ** to modify the database connection must be deferred until after the 6809 ** completion of the [sqlite3_step()] call that triggered the commit 6810 ** or rollback hook in the first place. 6811 ** Note that running any other SQL statements, including SELECT statements, 6812 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6813 ** the database connections for the meaning of "modify" in this paragraph. 6814 ** 6815 ** ^Registering a NULL function disables the callback. 6816 ** 6817 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6818 ** operation is allowed to continue normally. ^If the commit hook 6819 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6820 ** ^The rollback hook is invoked on a rollback that results from a commit 6821 ** hook returning non-zero, just as it would be with any other rollback. 6822 ** 6823 ** ^For the purposes of this API, a transaction is said to have been 6824 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6825 ** an error or constraint causes an implicit rollback to occur. 6826 ** ^The rollback callback is not invoked if a transaction is 6827 ** automatically rolled back because the database connection is closed. 6828 ** 6829 ** See also the [sqlite3_update_hook()] interface. 6830 */ 6831 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6832 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6833 6834 /* 6835 ** CAPI3REF: Autovacuum Compaction Amount Callback 6836 ** METHOD: sqlite3 6837 ** 6838 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6839 ** function C that is invoked prior to each autovacuum of the database 6840 ** file. ^The callback is passed a copy of the generic data pointer (P), 6841 ** the schema-name of the attached database that is being autovacuumed, 6842 ** the size of the database file in pages, the number of free pages, 6843 ** and the number of bytes per page, respectively. The callback should 6844 ** return the number of free pages that should be removed by the 6845 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6846 ** ^If the value returned is greater than or equal to the number of 6847 ** free pages, then a complete autovacuum happens. 6848 ** 6849 ** <p>^If there are multiple ATTACH-ed database files that are being 6850 ** modified as part of a transaction commit, then the autovacuum pages 6851 ** callback is invoked separately for each file. 6852 ** 6853 ** <p><b>The callback is not reentrant.</b> The callback function should 6854 ** not attempt to invoke any other SQLite interface. If it does, bad 6855 ** things may happen, including segmentation faults and corrupt database 6856 ** files. The callback function should be a simple function that 6857 ** does some arithmetic on its input parameters and returns a result. 6858 ** 6859 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6860 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6861 ** invoked whenever the database connection closes or when the callback 6862 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6863 ** 6864 ** <p>^There is only one autovacuum pages callback per database connection. 6865 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6866 ** previous invocations for that database connection. ^If the callback 6867 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6868 ** then the autovacuum steps callback is canceled. The return value 6869 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6870 ** be some other error code if something goes wrong. The current 6871 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6872 ** return codes might be added in future releases. 6873 ** 6874 ** <p>If no autovacuum pages callback is specified (the usual case) or 6875 ** a NULL pointer is provided for the callback, 6876 ** then the default behavior is to vacuum all free pages. So, in other 6877 ** words, the default behavior is the same as if the callback function 6878 ** were something like this: 6879 ** 6880 ** <blockquote><pre> 6881 ** unsigned int demonstration_autovac_pages_callback( 6882 ** void *pClientData, 6883 ** const char *zSchema, 6884 ** unsigned int nDbPage, 6885 ** unsigned int nFreePage, 6886 ** unsigned int nBytePerPage 6887 ** ){ 6888 ** return nFreePage; 6889 ** } 6890 ** </pre></blockquote> 6891 */ 6892 SQLITE_API int sqlite3_autovacuum_pages( 6893 sqlite3 *db, 6894 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6895 void*, 6896 void(*)(void*) 6897 ); 6898 6899 6900 /* 6901 ** CAPI3REF: Data Change Notification Callbacks 6902 ** METHOD: sqlite3 6903 ** 6904 ** ^The sqlite3_update_hook() interface registers a callback function 6905 ** with the [database connection] identified by the first argument 6906 ** to be invoked whenever a row is updated, inserted or deleted in 6907 ** a [rowid table]. 6908 ** ^Any callback set by a previous call to this function 6909 ** for the same database connection is overridden. 6910 ** 6911 ** ^The second argument is a pointer to the function to invoke when a 6912 ** row is updated, inserted or deleted in a rowid table. 6913 ** ^The first argument to the callback is a copy of the third argument 6914 ** to sqlite3_update_hook(). 6915 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6916 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6917 ** to be invoked. 6918 ** ^The third and fourth arguments to the callback contain pointers to the 6919 ** database and table name containing the affected row. 6920 ** ^The final callback parameter is the [rowid] of the row. 6921 ** ^In the case of an update, this is the [rowid] after the update takes place. 6922 ** 6923 ** ^(The update hook is not invoked when internal system tables are 6924 ** modified (i.e. sqlite_sequence).)^ 6925 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6926 ** 6927 ** ^In the current implementation, the update hook 6928 ** is not invoked when conflicting rows are deleted because of an 6929 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6930 ** invoked when rows are deleted using the [truncate optimization]. 6931 ** The exceptions defined in this paragraph might change in a future 6932 ** release of SQLite. 6933 ** 6934 ** The update hook implementation must not do anything that will modify 6935 ** the database connection that invoked the update hook. Any actions 6936 ** to modify the database connection must be deferred until after the 6937 ** completion of the [sqlite3_step()] call that triggered the update hook. 6938 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6939 ** database connections for the meaning of "modify" in this paragraph. 6940 ** 6941 ** ^The sqlite3_update_hook(D,C,P) function 6942 ** returns the P argument from the previous call 6943 ** on the same [database connection] D, or NULL for 6944 ** the first call on D. 6945 ** 6946 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6947 ** and [sqlite3_preupdate_hook()] interfaces. 6948 */ 6949 SQLITE_API void *sqlite3_update_hook( 6950 sqlite3*, 6951 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6952 void* 6953 ); 6954 6955 /* 6956 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6957 ** 6958 ** ^(This routine enables or disables the sharing of the database cache 6959 ** and schema data structures between [database connection | connections] 6960 ** to the same database. Sharing is enabled if the argument is true 6961 ** and disabled if the argument is false.)^ 6962 ** 6963 ** This interface is omitted if SQLite is compiled with 6964 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6965 ** compile-time option is recommended because the 6966 ** [use of shared cache mode is discouraged]. 6967 ** 6968 ** ^Cache sharing is enabled and disabled for an entire process. 6969 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6970 ** In prior versions of SQLite, 6971 ** sharing was enabled or disabled for each thread separately. 6972 ** 6973 ** ^(The cache sharing mode set by this interface effects all subsequent 6974 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6975 ** Existing database connections continue to use the sharing mode 6976 ** that was in effect at the time they were opened.)^ 6977 ** 6978 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6979 ** successfully. An [error code] is returned otherwise.)^ 6980 ** 6981 ** ^Shared cache is disabled by default. It is recommended that it stay 6982 ** that way. In other words, do not use this routine. This interface 6983 ** continues to be provided for historical compatibility, but its use is 6984 ** discouraged. Any use of shared cache is discouraged. If shared cache 6985 ** must be used, it is recommended that shared cache only be enabled for 6986 ** individual database connections using the [sqlite3_open_v2()] interface 6987 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6988 ** 6989 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6990 ** and will always return SQLITE_MISUSE. On those systems, 6991 ** shared cache mode should be enabled per-database connection via 6992 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6993 ** 6994 ** This interface is threadsafe on processors where writing a 6995 ** 32-bit integer is atomic. 6996 ** 6997 ** See Also: [SQLite Shared-Cache Mode] 6998 */ 6999 SQLITE_API int sqlite3_enable_shared_cache(int); 7000 7001 /* 7002 ** CAPI3REF: Attempt To Free Heap Memory 7003 ** 7004 ** ^The sqlite3_release_memory() interface attempts to free N bytes 7005 ** of heap memory by deallocating non-essential memory allocations 7006 ** held by the database library. Memory used to cache database 7007 ** pages to improve performance is an example of non-essential memory. 7008 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 7009 ** which might be more or less than the amount requested. 7010 ** ^The sqlite3_release_memory() routine is a no-op returning zero 7011 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 7012 ** 7013 ** See also: [sqlite3_db_release_memory()] 7014 */ 7015 SQLITE_API int sqlite3_release_memory(int); 7016 7017 /* 7018 ** CAPI3REF: Free Memory Used By A Database Connection 7019 ** METHOD: sqlite3 7020 ** 7021 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 7022 ** memory as possible from database connection D. Unlike the 7023 ** [sqlite3_release_memory()] interface, this interface is in effect even 7024 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 7025 ** omitted. 7026 ** 7027 ** See also: [sqlite3_release_memory()] 7028 */ 7029 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 7030 7031 /* 7032 ** CAPI3REF: Impose A Limit On Heap Size 7033 ** 7034 ** These interfaces impose limits on the amount of heap memory that will be 7035 ** by all database connections within a single process. 7036 ** 7037 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 7038 ** soft limit on the amount of heap memory that may be allocated by SQLite. 7039 ** ^SQLite strives to keep heap memory utilization below the soft heap 7040 ** limit by reducing the number of pages held in the page cache 7041 ** as heap memory usages approaches the limit. 7042 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 7043 ** below the limit, it will exceed the limit rather than generate 7044 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 7045 ** is advisory only. 7046 ** 7047 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 7048 ** N bytes on the amount of memory that will be allocated. ^The 7049 ** sqlite3_hard_heap_limit64(N) interface is similar to 7050 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 7051 ** when the hard heap limit is reached. 7052 ** 7053 ** ^The return value from both sqlite3_soft_heap_limit64() and 7054 ** sqlite3_hard_heap_limit64() is the size of 7055 ** the heap limit prior to the call, or negative in the case of an 7056 ** error. ^If the argument N is negative 7057 ** then no change is made to the heap limit. Hence, the current 7058 ** size of heap limits can be determined by invoking 7059 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 7060 ** 7061 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 7062 ** 7063 ** ^The soft heap limit may not be greater than the hard heap limit. 7064 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 7065 ** is invoked with a value of N that is greater than the hard heap limit, 7066 ** the soft heap limit is set to the value of the hard heap limit. 7067 ** ^The soft heap limit is automatically enabled whenever the hard heap 7068 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 7069 ** the soft heap limit is outside the range of 1..N, then the soft heap 7070 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 7071 ** hard heap limit is enabled makes the soft heap limit equal to the 7072 ** hard heap limit. 7073 ** 7074 ** The memory allocation limits can also be adjusted using 7075 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 7076 ** 7077 ** ^(The heap limits are not enforced in the current implementation 7078 ** if one or more of following conditions are true: 7079 ** 7080 ** <ul> 7081 ** <li> The limit value is set to zero. 7082 ** <li> Memory accounting is disabled using a combination of the 7083 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 7084 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 7085 ** <li> An alternative page cache implementation is specified using 7086 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 7087 ** <li> The page cache allocates from its own memory pool supplied 7088 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 7089 ** from the heap. 7090 ** </ul>)^ 7091 ** 7092 ** The circumstances under which SQLite will enforce the heap limits may 7093 ** changes in future releases of SQLite. 7094 */ 7095 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 7096 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 7097 7098 /* 7099 ** CAPI3REF: Deprecated Soft Heap Limit Interface 7100 ** DEPRECATED 7101 ** 7102 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 7103 ** interface. This routine is provided for historical compatibility 7104 ** only. All new applications should use the 7105 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 7106 */ 7107 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 7108 7109 7110 /* 7111 ** CAPI3REF: Extract Metadata About A Column Of A Table 7112 ** METHOD: sqlite3 7113 ** 7114 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 7115 ** information about column C of table T in database D 7116 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 7117 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 7118 ** the final five arguments with appropriate values if the specified 7119 ** column exists. ^The sqlite3_table_column_metadata() interface returns 7120 ** SQLITE_ERROR if the specified column does not exist. 7121 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 7122 ** NULL pointer, then this routine simply checks for the existence of the 7123 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 7124 ** does not. If the table name parameter T in a call to 7125 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 7126 ** undefined behavior. 7127 ** 7128 ** ^The column is identified by the second, third and fourth parameters to 7129 ** this function. ^(The second parameter is either the name of the database 7130 ** (i.e. "main", "temp", or an attached database) containing the specified 7131 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 7132 ** for the table using the same algorithm used by the database engine to 7133 ** resolve unqualified table references. 7134 ** 7135 ** ^The third and fourth parameters to this function are the table and column 7136 ** name of the desired column, respectively. 7137 ** 7138 ** ^Metadata is returned by writing to the memory locations passed as the 5th 7139 ** and subsequent parameters to this function. ^Any of these arguments may be 7140 ** NULL, in which case the corresponding element of metadata is omitted. 7141 ** 7142 ** ^(<blockquote> 7143 ** <table border="1"> 7144 ** <tr><th> Parameter <th> Output<br>Type <th> Description 7145 ** 7146 ** <tr><td> 5th <td> const char* <td> Data type 7147 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 7148 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 7149 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 7150 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 7151 ** </table> 7152 ** </blockquote>)^ 7153 ** 7154 ** ^The memory pointed to by the character pointers returned for the 7155 ** declaration type and collation sequence is valid until the next 7156 ** call to any SQLite API function. 7157 ** 7158 ** ^If the specified table is actually a view, an [error code] is returned. 7159 ** 7160 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 7161 ** is not a [WITHOUT ROWID] table and an 7162 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 7163 ** parameters are set for the explicitly declared column. ^(If there is no 7164 ** [INTEGER PRIMARY KEY] column, then the outputs 7165 ** for the [rowid] are set as follows: 7166 ** 7167 ** <pre> 7168 ** data type: "INTEGER" 7169 ** collation sequence: "BINARY" 7170 ** not null: 0 7171 ** primary key: 1 7172 ** auto increment: 0 7173 ** </pre>)^ 7174 ** 7175 ** ^This function causes all database schemas to be read from disk and 7176 ** parsed, if that has not already been done, and returns an error if 7177 ** any errors are encountered while loading the schema. 7178 */ 7179 SQLITE_API int sqlite3_table_column_metadata( 7180 sqlite3 *db, /* Connection handle */ 7181 const char *zDbName, /* Database name or NULL */ 7182 const char *zTableName, /* Table name */ 7183 const char *zColumnName, /* Column name */ 7184 char const **pzDataType, /* OUTPUT: Declared data type */ 7185 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 7186 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 7187 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 7188 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 7189 ); 7190 7191 /* 7192 ** CAPI3REF: Load An Extension 7193 ** METHOD: sqlite3 7194 ** 7195 ** ^This interface loads an SQLite extension library from the named file. 7196 ** 7197 ** ^The sqlite3_load_extension() interface attempts to load an 7198 ** [SQLite extension] library contained in the file zFile. If 7199 ** the file cannot be loaded directly, attempts are made to load 7200 ** with various operating-system specific extensions added. 7201 ** So for example, if "samplelib" cannot be loaded, then names like 7202 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 7203 ** be tried also. 7204 ** 7205 ** ^The entry point is zProc. 7206 ** ^(zProc may be 0, in which case SQLite will try to come up with an 7207 ** entry point name on its own. It first tries "sqlite3_extension_init". 7208 ** If that does not work, it constructs a name "sqlite3_X_init" where the 7209 ** X is consists of the lower-case equivalent of all ASCII alphabetic 7210 ** characters in the filename from the last "/" to the first following 7211 ** "." and omitting any initial "lib".)^ 7212 ** ^The sqlite3_load_extension() interface returns 7213 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 7214 ** ^If an error occurs and pzErrMsg is not 0, then the 7215 ** [sqlite3_load_extension()] interface shall attempt to 7216 ** fill *pzErrMsg with error message text stored in memory 7217 ** obtained from [sqlite3_malloc()]. The calling function 7218 ** should free this memory by calling [sqlite3_free()]. 7219 ** 7220 ** ^Extension loading must be enabled using 7221 ** [sqlite3_enable_load_extension()] or 7222 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 7223 ** prior to calling this API, 7224 ** otherwise an error will be returned. 7225 ** 7226 ** <b>Security warning:</b> It is recommended that the 7227 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 7228 ** interface. The use of the [sqlite3_enable_load_extension()] interface 7229 ** should be avoided. This will keep the SQL function [load_extension()] 7230 ** disabled and prevent SQL injections from giving attackers 7231 ** access to extension loading capabilities. 7232 ** 7233 ** See also the [load_extension() SQL function]. 7234 */ 7235 SQLITE_API int sqlite3_load_extension( 7236 sqlite3 *db, /* Load the extension into this database connection */ 7237 const char *zFile, /* Name of the shared library containing extension */ 7238 const char *zProc, /* Entry point. Derived from zFile if 0 */ 7239 char **pzErrMsg /* Put error message here if not 0 */ 7240 ); 7241 7242 /* 7243 ** CAPI3REF: Enable Or Disable Extension Loading 7244 ** METHOD: sqlite3 7245 ** 7246 ** ^So as not to open security holes in older applications that are 7247 ** unprepared to deal with [extension loading], and as a means of disabling 7248 ** [extension loading] while evaluating user-entered SQL, the following API 7249 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 7250 ** 7251 ** ^Extension loading is off by default. 7252 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 7253 ** to turn extension loading on and call it with onoff==0 to turn 7254 ** it back off again. 7255 ** 7256 ** ^This interface enables or disables both the C-API 7257 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 7258 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7259 ** to enable or disable only the C-API.)^ 7260 ** 7261 ** <b>Security warning:</b> It is recommended that extension loading 7262 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7263 ** rather than this interface, so the [load_extension()] SQL function 7264 ** remains disabled. This will prevent SQL injections from giving attackers 7265 ** access to extension loading capabilities. 7266 */ 7267 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7268 7269 /* 7270 ** CAPI3REF: Automatically Load Statically Linked Extensions 7271 ** 7272 ** ^This interface causes the xEntryPoint() function to be invoked for 7273 ** each new [database connection] that is created. The idea here is that 7274 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7275 ** that is to be automatically loaded into all new database connections. 7276 ** 7277 ** ^(Even though the function prototype shows that xEntryPoint() takes 7278 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7279 ** arguments and expects an integer result as if the signature of the 7280 ** entry point where as follows: 7281 ** 7282 ** <blockquote><pre> 7283 ** int xEntryPoint( 7284 ** sqlite3 *db, 7285 ** const char **pzErrMsg, 7286 ** const struct sqlite3_api_routines *pThunk 7287 ** ); 7288 ** </pre></blockquote>)^ 7289 ** 7290 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7291 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7292 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7293 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7294 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7295 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7296 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7297 ** 7298 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7299 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7300 ** will be called more than once for each database connection that is opened. 7301 ** 7302 ** See also: [sqlite3_reset_auto_extension()] 7303 ** and [sqlite3_cancel_auto_extension()] 7304 */ 7305 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7306 7307 /* 7308 ** CAPI3REF: Cancel Automatic Extension Loading 7309 ** 7310 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7311 ** initialization routine X that was registered using a prior call to 7312 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7313 ** routine returns 1 if initialization routine X was successfully 7314 ** unregistered and it returns 0 if X was not on the list of initialization 7315 ** routines. 7316 */ 7317 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7318 7319 /* 7320 ** CAPI3REF: Reset Automatic Extension Loading 7321 ** 7322 ** ^This interface disables all automatic extensions previously 7323 ** registered using [sqlite3_auto_extension()]. 7324 */ 7325 SQLITE_API void sqlite3_reset_auto_extension(void); 7326 7327 /* 7328 ** Structures used by the virtual table interface 7329 */ 7330 typedef struct sqlite3_vtab sqlite3_vtab; 7331 typedef struct sqlite3_index_info sqlite3_index_info; 7332 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7333 typedef struct sqlite3_module sqlite3_module; 7334 7335 /* 7336 ** CAPI3REF: Virtual Table Object 7337 ** KEYWORDS: sqlite3_module {virtual table module} 7338 ** 7339 ** This structure, sometimes called a "virtual table module", 7340 ** defines the implementation of a [virtual table]. 7341 ** This structure consists mostly of methods for the module. 7342 ** 7343 ** ^A virtual table module is created by filling in a persistent 7344 ** instance of this structure and passing a pointer to that instance 7345 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7346 ** ^The registration remains valid until it is replaced by a different 7347 ** module or until the [database connection] closes. The content 7348 ** of this structure must not change while it is registered with 7349 ** any database connection. 7350 */ 7351 struct sqlite3_module { 7352 int iVersion; 7353 int (*xCreate)(sqlite3*, void *pAux, 7354 int argc, const char *const*argv, 7355 sqlite3_vtab **ppVTab, char**); 7356 int (*xConnect)(sqlite3*, void *pAux, 7357 int argc, const char *const*argv, 7358 sqlite3_vtab **ppVTab, char**); 7359 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7360 int (*xDisconnect)(sqlite3_vtab *pVTab); 7361 int (*xDestroy)(sqlite3_vtab *pVTab); 7362 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7363 int (*xClose)(sqlite3_vtab_cursor*); 7364 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7365 int argc, sqlite3_value **argv); 7366 int (*xNext)(sqlite3_vtab_cursor*); 7367 int (*xEof)(sqlite3_vtab_cursor*); 7368 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7369 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7370 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7371 int (*xBegin)(sqlite3_vtab *pVTab); 7372 int (*xSync)(sqlite3_vtab *pVTab); 7373 int (*xCommit)(sqlite3_vtab *pVTab); 7374 int (*xRollback)(sqlite3_vtab *pVTab); 7375 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7376 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7377 void **ppArg); 7378 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7379 /* The methods above are in version 1 of the sqlite_module object. Those 7380 ** below are for version 2 and greater. */ 7381 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7382 int (*xRelease)(sqlite3_vtab *pVTab, int); 7383 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7384 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7385 ** Those below are for version 3 and greater. */ 7386 int (*xShadowName)(const char*); 7387 /* The methods above are in versions 1 through 3 of the sqlite_module object. 7388 ** Those below are for version 4 and greater. */ 7389 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema, 7390 const char *zTabName, int mFlags, char **pzErr); 7391 }; 7392 7393 /* 7394 ** CAPI3REF: Virtual Table Indexing Information 7395 ** KEYWORDS: sqlite3_index_info 7396 ** 7397 ** The sqlite3_index_info structure and its substructures is used as part 7398 ** of the [virtual table] interface to 7399 ** pass information into and receive the reply from the [xBestIndex] 7400 ** method of a [virtual table module]. The fields under **Inputs** are the 7401 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7402 ** results into the **Outputs** fields. 7403 ** 7404 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7405 ** 7406 ** <blockquote>column OP expr</blockquote> 7407 ** 7408 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7409 ** stored in aConstraint[].op using one of the 7410 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7411 ** ^(The index of the column is stored in 7412 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7413 ** expr on the right-hand side can be evaluated (and thus the constraint 7414 ** is usable) and false if it cannot.)^ 7415 ** 7416 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7417 ** and makes other simplifications to the WHERE clause in an attempt to 7418 ** get as many WHERE clause terms into the form shown above as possible. 7419 ** ^The aConstraint[] array only reports WHERE clause terms that are 7420 ** relevant to the particular virtual table being queried. 7421 ** 7422 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7423 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7424 ** 7425 ** The colUsed field indicates which columns of the virtual table may be 7426 ** required by the current scan. Virtual table columns are numbered from 7427 ** zero in the order in which they appear within the CREATE TABLE statement 7428 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7429 ** the corresponding bit is set within the colUsed mask if the column may be 7430 ** required by SQLite. If the table has at least 64 columns and any column 7431 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7432 ** set. In other words, column iCol may be required if the expression 7433 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7434 ** non-zero. 7435 ** 7436 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7437 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7438 ** the right-hand side of the corresponding aConstraint[] is evaluated 7439 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7440 ** is true, then the constraint is assumed to be fully handled by the 7441 ** virtual table and might not be checked again by the byte code.)^ ^(The 7442 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7443 ** is left in its default setting of false, the constraint will always be 7444 ** checked separately in byte code. If the omit flag is change to true, then 7445 ** the constraint may or may not be checked in byte code. In other words, 7446 ** when the omit flag is true there is no guarantee that the constraint will 7447 ** not be checked again using byte code.)^ 7448 ** 7449 ** ^The idxNum and idxStr values are recorded and passed into the 7450 ** [xFilter] method. 7451 ** ^[sqlite3_free()] is used to free idxStr if and only if 7452 ** needToFreeIdxStr is true. 7453 ** 7454 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7455 ** the correct order to satisfy the ORDER BY clause so that no separate 7456 ** sorting step is required. 7457 ** 7458 ** ^The estimatedCost value is an estimate of the cost of a particular 7459 ** strategy. A cost of N indicates that the cost of the strategy is similar 7460 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7461 ** indicates that the expense of the operation is similar to that of a 7462 ** binary search on a unique indexed field of an SQLite table with N rows. 7463 ** 7464 ** ^The estimatedRows value is an estimate of the number of rows that 7465 ** will be returned by the strategy. 7466 ** 7467 ** The xBestIndex method may optionally populate the idxFlags field with a 7468 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7469 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7470 ** assumes that the strategy may visit at most one row. 7471 ** 7472 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7473 ** SQLite also assumes that if a call to the xUpdate() method is made as 7474 ** part of the same statement to delete or update a virtual table row and the 7475 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7476 ** any database changes. In other words, if the xUpdate() returns 7477 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7478 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7479 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7480 ** the xUpdate method are automatically rolled back by SQLite. 7481 ** 7482 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7483 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7484 ** If a virtual table extension is 7485 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7486 ** to read or write the estimatedRows field are undefined (but are likely 7487 ** to include crashing the application). The estimatedRows field should 7488 ** therefore only be used if [sqlite3_libversion_number()] returns a 7489 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7490 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7491 ** It may therefore only be used if 7492 ** sqlite3_libversion_number() returns a value greater than or equal to 7493 ** 3009000. 7494 */ 7495 struct sqlite3_index_info { 7496 /* Inputs */ 7497 int nConstraint; /* Number of entries in aConstraint */ 7498 struct sqlite3_index_constraint { 7499 int iColumn; /* Column constrained. -1 for ROWID */ 7500 unsigned char op; /* Constraint operator */ 7501 unsigned char usable; /* True if this constraint is usable */ 7502 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7503 } *aConstraint; /* Table of WHERE clause constraints */ 7504 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7505 struct sqlite3_index_orderby { 7506 int iColumn; /* Column number */ 7507 unsigned char desc; /* True for DESC. False for ASC. */ 7508 } *aOrderBy; /* The ORDER BY clause */ 7509 /* Outputs */ 7510 struct sqlite3_index_constraint_usage { 7511 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7512 unsigned char omit; /* Do not code a test for this constraint */ 7513 } *aConstraintUsage; 7514 int idxNum; /* Number used to identify the index */ 7515 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7516 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7517 int orderByConsumed; /* True if output is already ordered */ 7518 double estimatedCost; /* Estimated cost of using this index */ 7519 /* Fields below are only available in SQLite 3.8.2 and later */ 7520 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7521 /* Fields below are only available in SQLite 3.9.0 and later */ 7522 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7523 /* Fields below are only available in SQLite 3.10.0 and later */ 7524 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7525 }; 7526 7527 /* 7528 ** CAPI3REF: Virtual Table Scan Flags 7529 ** 7530 ** Virtual table implementations are allowed to set the 7531 ** [sqlite3_index_info].idxFlags field to some combination of 7532 ** these bits. 7533 */ 7534 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7535 7536 /* 7537 ** CAPI3REF: Virtual Table Constraint Operator Codes 7538 ** 7539 ** These macros define the allowed values for the 7540 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7541 ** an operator that is part of a constraint term in the WHERE clause of 7542 ** a query that uses a [virtual table]. 7543 ** 7544 ** ^The left-hand operand of the operator is given by the corresponding 7545 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7546 ** operand is the rowid. 7547 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7548 ** operators have no left-hand operand, and so for those operators the 7549 ** corresponding aConstraint[].iColumn is meaningless and should not be 7550 ** used. 7551 ** 7552 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7553 ** value 255 are reserved to represent functions that are overloaded 7554 ** by the [xFindFunction|xFindFunction method] of the virtual table 7555 ** implementation. 7556 ** 7557 ** The right-hand operands for each constraint might be accessible using 7558 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7559 ** operand is only available if it appears as a single constant literal 7560 ** in the input SQL. If the right-hand operand is another column or an 7561 ** expression (even a constant expression) or a parameter, then the 7562 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7563 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7564 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7565 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7566 ** always return SQLITE_NOTFOUND. 7567 ** 7568 ** The collating sequence to be used for comparison can be found using 7569 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7570 ** tables, the collating sequence of constraints does not matter (for example 7571 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7572 ** interface is not commonly needed. 7573 */ 7574 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7575 #define SQLITE_INDEX_CONSTRAINT_GT 4 7576 #define SQLITE_INDEX_CONSTRAINT_LE 8 7577 #define SQLITE_INDEX_CONSTRAINT_LT 16 7578 #define SQLITE_INDEX_CONSTRAINT_GE 32 7579 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7580 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7581 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7582 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7583 #define SQLITE_INDEX_CONSTRAINT_NE 68 7584 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7585 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7586 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7587 #define SQLITE_INDEX_CONSTRAINT_IS 72 7588 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7589 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7590 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7591 7592 /* 7593 ** CAPI3REF: Register A Virtual Table Implementation 7594 ** METHOD: sqlite3 7595 ** 7596 ** ^These routines are used to register a new [virtual table module] name. 7597 ** ^Module names must be registered before 7598 ** creating a new [virtual table] using the module and before using a 7599 ** preexisting [virtual table] for the module. 7600 ** 7601 ** ^The module name is registered on the [database connection] specified 7602 ** by the first parameter. ^The name of the module is given by the 7603 ** second parameter. ^The third parameter is a pointer to 7604 ** the implementation of the [virtual table module]. ^The fourth 7605 ** parameter is an arbitrary client data pointer that is passed through 7606 ** into the [xCreate] and [xConnect] methods of the virtual table module 7607 ** when a new virtual table is be being created or reinitialized. 7608 ** 7609 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7610 ** is a pointer to a destructor for the pClientData. ^SQLite will 7611 ** invoke the destructor function (if it is not NULL) when SQLite 7612 ** no longer needs the pClientData pointer. ^The destructor will also 7613 ** be invoked if the call to sqlite3_create_module_v2() fails. 7614 ** ^The sqlite3_create_module() 7615 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7616 ** destructor. 7617 ** 7618 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7619 ** NULL then no new module is created and any existing modules with the 7620 ** same name are dropped. 7621 ** 7622 ** See also: [sqlite3_drop_modules()] 7623 */ 7624 SQLITE_API int sqlite3_create_module( 7625 sqlite3 *db, /* SQLite connection to register module with */ 7626 const char *zName, /* Name of the module */ 7627 const sqlite3_module *p, /* Methods for the module */ 7628 void *pClientData /* Client data for xCreate/xConnect */ 7629 ); 7630 SQLITE_API int sqlite3_create_module_v2( 7631 sqlite3 *db, /* SQLite connection to register module with */ 7632 const char *zName, /* Name of the module */ 7633 const sqlite3_module *p, /* Methods for the module */ 7634 void *pClientData, /* Client data for xCreate/xConnect */ 7635 void(*xDestroy)(void*) /* Module destructor function */ 7636 ); 7637 7638 /* 7639 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7640 ** METHOD: sqlite3 7641 ** 7642 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7643 ** table modules from database connection D except those named on list L. 7644 ** The L parameter must be either NULL or a pointer to an array of pointers 7645 ** to strings where the array is terminated by a single NULL pointer. 7646 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7647 ** 7648 ** See also: [sqlite3_create_module()] 7649 */ 7650 SQLITE_API int sqlite3_drop_modules( 7651 sqlite3 *db, /* Remove modules from this connection */ 7652 const char **azKeep /* Except, do not remove the ones named here */ 7653 ); 7654 7655 /* 7656 ** CAPI3REF: Virtual Table Instance Object 7657 ** KEYWORDS: sqlite3_vtab 7658 ** 7659 ** Every [virtual table module] implementation uses a subclass 7660 ** of this object to describe a particular instance 7661 ** of the [virtual table]. Each subclass will 7662 ** be tailored to the specific needs of the module implementation. 7663 ** The purpose of this superclass is to define certain fields that are 7664 ** common to all module implementations. 7665 ** 7666 ** ^Virtual tables methods can set an error message by assigning a 7667 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7668 ** take care that any prior string is freed by a call to [sqlite3_free()] 7669 ** prior to assigning a new string to zErrMsg. ^After the error message 7670 ** is delivered up to the client application, the string will be automatically 7671 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7672 */ 7673 struct sqlite3_vtab { 7674 const sqlite3_module *pModule; /* The module for this virtual table */ 7675 int nRef; /* Number of open cursors */ 7676 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7677 /* Virtual table implementations will typically add additional fields */ 7678 }; 7679 7680 /* 7681 ** CAPI3REF: Virtual Table Cursor Object 7682 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7683 ** 7684 ** Every [virtual table module] implementation uses a subclass of the 7685 ** following structure to describe cursors that point into the 7686 ** [virtual table] and are used 7687 ** to loop through the virtual table. Cursors are created using the 7688 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7689 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7690 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7691 ** of the module. Each module implementation will define 7692 ** the content of a cursor structure to suit its own needs. 7693 ** 7694 ** This superclass exists in order to define fields of the cursor that 7695 ** are common to all implementations. 7696 */ 7697 struct sqlite3_vtab_cursor { 7698 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7699 /* Virtual table implementations will typically add additional fields */ 7700 }; 7701 7702 /* 7703 ** CAPI3REF: Declare The Schema Of A Virtual Table 7704 ** 7705 ** ^The [xCreate] and [xConnect] methods of a 7706 ** [virtual table module] call this interface 7707 ** to declare the format (the names and datatypes of the columns) of 7708 ** the virtual tables they implement. 7709 */ 7710 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7711 7712 /* 7713 ** CAPI3REF: Overload A Function For A Virtual Table 7714 ** METHOD: sqlite3 7715 ** 7716 ** ^(Virtual tables can provide alternative implementations of functions 7717 ** using the [xFindFunction] method of the [virtual table module]. 7718 ** But global versions of those functions 7719 ** must exist in order to be overloaded.)^ 7720 ** 7721 ** ^(This API makes sure a global version of a function with a particular 7722 ** name and number of parameters exists. If no such function exists 7723 ** before this API is called, a new function is created.)^ ^The implementation 7724 ** of the new function always causes an exception to be thrown. So 7725 ** the new function is not good for anything by itself. Its only 7726 ** purpose is to be a placeholder function that can be overloaded 7727 ** by a [virtual table]. 7728 */ 7729 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7730 7731 /* 7732 ** CAPI3REF: A Handle To An Open BLOB 7733 ** KEYWORDS: {BLOB handle} {BLOB handles} 7734 ** 7735 ** An instance of this object represents an open BLOB on which 7736 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7737 ** ^Objects of this type are created by [sqlite3_blob_open()] 7738 ** and destroyed by [sqlite3_blob_close()]. 7739 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7740 ** can be used to read or write small subsections of the BLOB. 7741 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7742 */ 7743 typedef struct sqlite3_blob sqlite3_blob; 7744 7745 /* 7746 ** CAPI3REF: Open A BLOB For Incremental I/O 7747 ** METHOD: sqlite3 7748 ** CONSTRUCTOR: sqlite3_blob 7749 ** 7750 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7751 ** in row iRow, column zColumn, table zTable in database zDb; 7752 ** in other words, the same BLOB that would be selected by: 7753 ** 7754 ** <pre> 7755 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7756 ** </pre>)^ 7757 ** 7758 ** ^(Parameter zDb is not the filename that contains the database, but 7759 ** rather the symbolic name of the database. For attached databases, this is 7760 ** the name that appears after the AS keyword in the [ATTACH] statement. 7761 ** For the main database file, the database name is "main". For TEMP 7762 ** tables, the database name is "temp".)^ 7763 ** 7764 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7765 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7766 ** read-only access. 7767 ** 7768 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7769 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7770 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7771 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7772 ** on *ppBlob after this function it returns. 7773 ** 7774 ** This function fails with SQLITE_ERROR if any of the following are true: 7775 ** <ul> 7776 ** <li> ^(Database zDb does not exist)^, 7777 ** <li> ^(Table zTable does not exist within database zDb)^, 7778 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7779 ** <li> ^(Column zColumn does not exist)^, 7780 ** <li> ^(Row iRow is not present in the table)^, 7781 ** <li> ^(The specified column of row iRow contains a value that is not 7782 ** a TEXT or BLOB value)^, 7783 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7784 ** constraint and the blob is being opened for read/write access)^, 7785 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7786 ** column zColumn is part of a [child key] definition and the blob is 7787 ** being opened for read/write access)^. 7788 ** </ul> 7789 ** 7790 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7791 ** [database connection] error code and message accessible via 7792 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7793 ** 7794 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7795 ** [sqlite3_blob_read()] interface and modified by using 7796 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7797 ** different row of the same table using the [sqlite3_blob_reopen()] 7798 ** interface. However, the column, table, or database of a [BLOB handle] 7799 ** cannot be changed after the [BLOB handle] is opened. 7800 ** 7801 ** ^(If the row that a BLOB handle points to is modified by an 7802 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7803 ** then the BLOB handle is marked as "expired". 7804 ** This is true if any column of the row is changed, even a column 7805 ** other than the one the BLOB handle is open on.)^ 7806 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7807 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7808 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7809 ** rolled back by the expiration of the BLOB. Such changes will eventually 7810 ** commit if the transaction continues to completion.)^ 7811 ** 7812 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7813 ** the opened blob. ^The size of a blob may not be changed by this 7814 ** interface. Use the [UPDATE] SQL command to change the size of a 7815 ** blob. 7816 ** 7817 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7818 ** and the built-in [zeroblob] SQL function may be used to create a 7819 ** zero-filled blob to read or write using the incremental-blob interface. 7820 ** 7821 ** To avoid a resource leak, every open [BLOB handle] should eventually 7822 ** be released by a call to [sqlite3_blob_close()]. 7823 ** 7824 ** See also: [sqlite3_blob_close()], 7825 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7826 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7827 */ 7828 SQLITE_API int sqlite3_blob_open( 7829 sqlite3*, 7830 const char *zDb, 7831 const char *zTable, 7832 const char *zColumn, 7833 sqlite3_int64 iRow, 7834 int flags, 7835 sqlite3_blob **ppBlob 7836 ); 7837 7838 /* 7839 ** CAPI3REF: Move a BLOB Handle to a New Row 7840 ** METHOD: sqlite3_blob 7841 ** 7842 ** ^This function is used to move an existing [BLOB handle] so that it points 7843 ** to a different row of the same database table. ^The new row is identified 7844 ** by the rowid value passed as the second argument. Only the row can be 7845 ** changed. ^The database, table and column on which the blob handle is open 7846 ** remain the same. Moving an existing [BLOB handle] to a new row is 7847 ** faster than closing the existing handle and opening a new one. 7848 ** 7849 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7850 ** it must exist and there must be either a blob or text value stored in 7851 ** the nominated column.)^ ^If the new row is not present in the table, or if 7852 ** it does not contain a blob or text value, or if another error occurs, an 7853 ** SQLite error code is returned and the blob handle is considered aborted. 7854 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7855 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7856 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7857 ** always returns zero. 7858 ** 7859 ** ^This function sets the database handle error code and message. 7860 */ 7861 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7862 7863 /* 7864 ** CAPI3REF: Close A BLOB Handle 7865 ** DESTRUCTOR: sqlite3_blob 7866 ** 7867 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7868 ** unconditionally. Even if this routine returns an error code, the 7869 ** handle is still closed.)^ 7870 ** 7871 ** ^If the blob handle being closed was opened for read-write access, and if 7872 ** the database is in auto-commit mode and there are no other open read-write 7873 ** blob handles or active write statements, the current transaction is 7874 ** committed. ^If an error occurs while committing the transaction, an error 7875 ** code is returned and the transaction rolled back. 7876 ** 7877 ** Calling this function with an argument that is not a NULL pointer or an 7878 ** open blob handle results in undefined behavior. ^Calling this routine 7879 ** with a null pointer (such as would be returned by a failed call to 7880 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7881 ** is passed a valid open blob handle, the values returned by the 7882 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7883 */ 7884 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7885 7886 /* 7887 ** CAPI3REF: Return The Size Of An Open BLOB 7888 ** METHOD: sqlite3_blob 7889 ** 7890 ** ^Returns the size in bytes of the BLOB accessible via the 7891 ** successfully opened [BLOB handle] in its only argument. ^The 7892 ** incremental blob I/O routines can only read or overwriting existing 7893 ** blob content; they cannot change the size of a blob. 7894 ** 7895 ** This routine only works on a [BLOB handle] which has been created 7896 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7897 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7898 ** to this routine results in undefined and probably undesirable behavior. 7899 */ 7900 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7901 7902 /* 7903 ** CAPI3REF: Read Data From A BLOB Incrementally 7904 ** METHOD: sqlite3_blob 7905 ** 7906 ** ^(This function is used to read data from an open [BLOB handle] into a 7907 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7908 ** from the open BLOB, starting at offset iOffset.)^ 7909 ** 7910 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7911 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7912 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7913 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7914 ** can be determined using the [sqlite3_blob_bytes()] interface. 7915 ** 7916 ** ^An attempt to read from an expired [BLOB handle] fails with an 7917 ** error code of [SQLITE_ABORT]. 7918 ** 7919 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7920 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7921 ** 7922 ** This routine only works on a [BLOB handle] which has been created 7923 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7924 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7925 ** to this routine results in undefined and probably undesirable behavior. 7926 ** 7927 ** See also: [sqlite3_blob_write()]. 7928 */ 7929 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7930 7931 /* 7932 ** CAPI3REF: Write Data Into A BLOB Incrementally 7933 ** METHOD: sqlite3_blob 7934 ** 7935 ** ^(This function is used to write data into an open [BLOB handle] from a 7936 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7937 ** into the open BLOB, starting at offset iOffset.)^ 7938 ** 7939 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7940 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7941 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7942 ** [database connection] error code and message accessible via 7943 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7944 ** 7945 ** ^If the [BLOB handle] passed as the first argument was not opened for 7946 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7947 ** this function returns [SQLITE_READONLY]. 7948 ** 7949 ** This function may only modify the contents of the BLOB; it is 7950 ** not possible to increase the size of a BLOB using this API. 7951 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7952 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7953 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7954 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7955 ** than zero [SQLITE_ERROR] is returned and no data is written. 7956 ** 7957 ** ^An attempt to write to an expired [BLOB handle] fails with an 7958 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7959 ** before the [BLOB handle] expired are not rolled back by the 7960 ** expiration of the handle, though of course those changes might 7961 ** have been overwritten by the statement that expired the BLOB handle 7962 ** or by other independent statements. 7963 ** 7964 ** This routine only works on a [BLOB handle] which has been created 7965 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7966 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7967 ** to this routine results in undefined and probably undesirable behavior. 7968 ** 7969 ** See also: [sqlite3_blob_read()]. 7970 */ 7971 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7972 7973 /* 7974 ** CAPI3REF: Virtual File System Objects 7975 ** 7976 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7977 ** that SQLite uses to interact 7978 ** with the underlying operating system. Most SQLite builds come with a 7979 ** single default VFS that is appropriate for the host computer. 7980 ** New VFSes can be registered and existing VFSes can be unregistered. 7981 ** The following interfaces are provided. 7982 ** 7983 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7984 ** ^Names are case sensitive. 7985 ** ^Names are zero-terminated UTF-8 strings. 7986 ** ^If there is no match, a NULL pointer is returned. 7987 ** ^If zVfsName is NULL then the default VFS is returned. 7988 ** 7989 ** ^New VFSes are registered with sqlite3_vfs_register(). 7990 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7991 ** ^The same VFS can be registered multiple times without injury. 7992 ** ^To make an existing VFS into the default VFS, register it again 7993 ** with the makeDflt flag set. If two different VFSes with the 7994 ** same name are registered, the behavior is undefined. If a 7995 ** VFS is registered with a name that is NULL or an empty string, 7996 ** then the behavior is undefined. 7997 ** 7998 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7999 ** ^(If the default VFS is unregistered, another VFS is chosen as 8000 ** the default. The choice for the new VFS is arbitrary.)^ 8001 */ 8002 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 8003 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 8004 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 8005 8006 /* 8007 ** CAPI3REF: Mutexes 8008 ** 8009 ** The SQLite core uses these routines for thread 8010 ** synchronization. Though they are intended for internal 8011 ** use by SQLite, code that links against SQLite is 8012 ** permitted to use any of these routines. 8013 ** 8014 ** The SQLite source code contains multiple implementations 8015 ** of these mutex routines. An appropriate implementation 8016 ** is selected automatically at compile-time. The following 8017 ** implementations are available in the SQLite core: 8018 ** 8019 ** <ul> 8020 ** <li> SQLITE_MUTEX_PTHREADS 8021 ** <li> SQLITE_MUTEX_W32 8022 ** <li> SQLITE_MUTEX_NOOP 8023 ** </ul> 8024 ** 8025 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 8026 ** that does no real locking and is appropriate for use in 8027 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 8028 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 8029 ** and Windows. 8030 ** 8031 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 8032 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 8033 ** implementation is included with the library. In this case the 8034 ** application must supply a custom mutex implementation using the 8035 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 8036 ** before calling sqlite3_initialize() or any other public sqlite3_ 8037 ** function that calls sqlite3_initialize(). 8038 ** 8039 ** ^The sqlite3_mutex_alloc() routine allocates a new 8040 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 8041 ** routine returns NULL if it is unable to allocate the requested 8042 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 8043 ** integer constants: 8044 ** 8045 ** <ul> 8046 ** <li> SQLITE_MUTEX_FAST 8047 ** <li> SQLITE_MUTEX_RECURSIVE 8048 ** <li> SQLITE_MUTEX_STATIC_MAIN 8049 ** <li> SQLITE_MUTEX_STATIC_MEM 8050 ** <li> SQLITE_MUTEX_STATIC_OPEN 8051 ** <li> SQLITE_MUTEX_STATIC_PRNG 8052 ** <li> SQLITE_MUTEX_STATIC_LRU 8053 ** <li> SQLITE_MUTEX_STATIC_PMEM 8054 ** <li> SQLITE_MUTEX_STATIC_APP1 8055 ** <li> SQLITE_MUTEX_STATIC_APP2 8056 ** <li> SQLITE_MUTEX_STATIC_APP3 8057 ** <li> SQLITE_MUTEX_STATIC_VFS1 8058 ** <li> SQLITE_MUTEX_STATIC_VFS2 8059 ** <li> SQLITE_MUTEX_STATIC_VFS3 8060 ** </ul> 8061 ** 8062 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 8063 ** cause sqlite3_mutex_alloc() to create 8064 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 8065 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 8066 ** The mutex implementation does not need to make a distinction 8067 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 8068 ** not want to. SQLite will only request a recursive mutex in 8069 ** cases where it really needs one. If a faster non-recursive mutex 8070 ** implementation is available on the host platform, the mutex subsystem 8071 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 8072 ** 8073 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 8074 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 8075 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 8076 ** used by the current version of SQLite. Future versions of SQLite 8077 ** may add additional static mutexes. Static mutexes are for internal 8078 ** use by SQLite only. Applications that use SQLite mutexes should 8079 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 8080 ** SQLITE_MUTEX_RECURSIVE. 8081 ** 8082 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 8083 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 8084 ** returns a different mutex on every call. ^For the static 8085 ** mutex types, the same mutex is returned on every call that has 8086 ** the same type number. 8087 ** 8088 ** ^The sqlite3_mutex_free() routine deallocates a previously 8089 ** allocated dynamic mutex. Attempting to deallocate a static 8090 ** mutex results in undefined behavior. 8091 ** 8092 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 8093 ** to enter a mutex. ^If another thread is already within the mutex, 8094 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 8095 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 8096 ** upon successful entry. ^(Mutexes created using 8097 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 8098 ** In such cases, the 8099 ** mutex must be exited an equal number of times before another thread 8100 ** can enter.)^ If the same thread tries to enter any mutex other 8101 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 8102 ** 8103 ** ^(Some systems (for example, Windows 95) do not support the operation 8104 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 8105 ** will always return SQLITE_BUSY. The SQLite core only ever uses 8106 ** sqlite3_mutex_try() as an optimization so this is acceptable 8107 ** behavior.)^ 8108 ** 8109 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 8110 ** previously entered by the same thread. The behavior 8111 ** is undefined if the mutex is not currently entered by the 8112 ** calling thread or is not currently allocated. 8113 ** 8114 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), 8115 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer, 8116 ** then any of the four routines behaves as a no-op. 8117 ** 8118 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 8119 */ 8120 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 8121 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 8122 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 8123 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 8124 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 8125 8126 /* 8127 ** CAPI3REF: Mutex Methods Object 8128 ** 8129 ** An instance of this structure defines the low-level routines 8130 ** used to allocate and use mutexes. 8131 ** 8132 ** Usually, the default mutex implementations provided by SQLite are 8133 ** sufficient, however the application has the option of substituting a custom 8134 ** implementation for specialized deployments or systems for which SQLite 8135 ** does not provide a suitable implementation. In this case, the application 8136 ** creates and populates an instance of this structure to pass 8137 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 8138 ** Additionally, an instance of this structure can be used as an 8139 ** output variable when querying the system for the current mutex 8140 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 8141 ** 8142 ** ^The xMutexInit method defined by this structure is invoked as 8143 ** part of system initialization by the sqlite3_initialize() function. 8144 ** ^The xMutexInit routine is called by SQLite exactly once for each 8145 ** effective call to [sqlite3_initialize()]. 8146 ** 8147 ** ^The xMutexEnd method defined by this structure is invoked as 8148 ** part of system shutdown by the sqlite3_shutdown() function. The 8149 ** implementation of this method is expected to release all outstanding 8150 ** resources obtained by the mutex methods implementation, especially 8151 ** those obtained by the xMutexInit method. ^The xMutexEnd() 8152 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 8153 ** 8154 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 8155 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 8156 ** xMutexNotheld) implement the following interfaces (respectively): 8157 ** 8158 ** <ul> 8159 ** <li> [sqlite3_mutex_alloc()] </li> 8160 ** <li> [sqlite3_mutex_free()] </li> 8161 ** <li> [sqlite3_mutex_enter()] </li> 8162 ** <li> [sqlite3_mutex_try()] </li> 8163 ** <li> [sqlite3_mutex_leave()] </li> 8164 ** <li> [sqlite3_mutex_held()] </li> 8165 ** <li> [sqlite3_mutex_notheld()] </li> 8166 ** </ul>)^ 8167 ** 8168 ** The only difference is that the public sqlite3_XXX functions enumerated 8169 ** above silently ignore any invocations that pass a NULL pointer instead 8170 ** of a valid mutex handle. The implementations of the methods defined 8171 ** by this structure are not required to handle this case. The results 8172 ** of passing a NULL pointer instead of a valid mutex handle are undefined 8173 ** (i.e. it is acceptable to provide an implementation that segfaults if 8174 ** it is passed a NULL pointer). 8175 ** 8176 ** The xMutexInit() method must be threadsafe. It must be harmless to 8177 ** invoke xMutexInit() multiple times within the same process and without 8178 ** intervening calls to xMutexEnd(). Second and subsequent calls to 8179 ** xMutexInit() must be no-ops. 8180 ** 8181 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 8182 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 8183 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 8184 ** memory allocation for a fast or recursive mutex. 8185 ** 8186 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 8187 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 8188 ** If xMutexInit fails in any way, it is expected to clean up after itself 8189 ** prior to returning. 8190 */ 8191 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 8192 struct sqlite3_mutex_methods { 8193 int (*xMutexInit)(void); 8194 int (*xMutexEnd)(void); 8195 sqlite3_mutex *(*xMutexAlloc)(int); 8196 void (*xMutexFree)(sqlite3_mutex *); 8197 void (*xMutexEnter)(sqlite3_mutex *); 8198 int (*xMutexTry)(sqlite3_mutex *); 8199 void (*xMutexLeave)(sqlite3_mutex *); 8200 int (*xMutexHeld)(sqlite3_mutex *); 8201 int (*xMutexNotheld)(sqlite3_mutex *); 8202 }; 8203 8204 /* 8205 ** CAPI3REF: Mutex Verification Routines 8206 ** 8207 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 8208 ** are intended for use inside assert() statements. The SQLite core 8209 ** never uses these routines except inside an assert() and applications 8210 ** are advised to follow the lead of the core. The SQLite core only 8211 ** provides implementations for these routines when it is compiled 8212 ** with the SQLITE_DEBUG flag. External mutex implementations 8213 ** are only required to provide these routines if SQLITE_DEBUG is 8214 ** defined and if NDEBUG is not defined. 8215 ** 8216 ** These routines should return true if the mutex in their argument 8217 ** is held or not held, respectively, by the calling thread. 8218 ** 8219 ** The implementation is not required to provide versions of these 8220 ** routines that actually work. If the implementation does not provide working 8221 ** versions of these routines, it should at least provide stubs that always 8222 ** return true so that one does not get spurious assertion failures. 8223 ** 8224 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 8225 ** the routine should return 1. This seems counter-intuitive since 8226 ** clearly the mutex cannot be held if it does not exist. But 8227 ** the reason the mutex does not exist is because the build is not 8228 ** using mutexes. And we do not want the assert() containing the 8229 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 8230 ** the appropriate thing to do. The sqlite3_mutex_notheld() 8231 ** interface should also return 1 when given a NULL pointer. 8232 */ 8233 #ifndef NDEBUG 8234 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 8235 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 8236 #endif 8237 8238 /* 8239 ** CAPI3REF: Mutex Types 8240 ** 8241 ** The [sqlite3_mutex_alloc()] interface takes a single argument 8242 ** which is one of these integer constants. 8243 ** 8244 ** The set of static mutexes may change from one SQLite release to the 8245 ** next. Applications that override the built-in mutex logic must be 8246 ** prepared to accommodate additional static mutexes. 8247 */ 8248 #define SQLITE_MUTEX_FAST 0 8249 #define SQLITE_MUTEX_RECURSIVE 1 8250 #define SQLITE_MUTEX_STATIC_MAIN 2 8251 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8252 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8253 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8254 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8255 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8256 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8257 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8258 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8259 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8260 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8261 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8262 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8263 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8264 8265 /* Legacy compatibility: */ 8266 #define SQLITE_MUTEX_STATIC_MASTER 2 8267 8268 8269 /* 8270 ** CAPI3REF: Retrieve the mutex for a database connection 8271 ** METHOD: sqlite3 8272 ** 8273 ** ^This interface returns a pointer the [sqlite3_mutex] object that 8274 ** serializes access to the [database connection] given in the argument 8275 ** when the [threading mode] is Serialized. 8276 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8277 ** routine returns a NULL pointer. 8278 */ 8279 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8280 8281 /* 8282 ** CAPI3REF: Low-Level Control Of Database Files 8283 ** METHOD: sqlite3 8284 ** KEYWORDS: {file control} 8285 ** 8286 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8287 ** xFileControl method for the [sqlite3_io_methods] object associated 8288 ** with a particular database identified by the second argument. ^The 8289 ** name of the database is "main" for the main database or "temp" for the 8290 ** TEMP database, or the name that appears after the AS keyword for 8291 ** databases that are added using the [ATTACH] SQL command. 8292 ** ^A NULL pointer can be used in place of "main" to refer to the 8293 ** main database file. 8294 ** ^The third and fourth parameters to this routine 8295 ** are passed directly through to the second and third parameters of 8296 ** the xFileControl method. ^The return value of the xFileControl 8297 ** method becomes the return value of this routine. 8298 ** 8299 ** A few opcodes for [sqlite3_file_control()] are handled directly 8300 ** by the SQLite core and never invoke the 8301 ** sqlite3_io_methods.xFileControl method. 8302 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8303 ** a pointer to the underlying [sqlite3_file] object to be written into 8304 ** the space pointed to by the 4th parameter. The 8305 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8306 ** the [sqlite3_file] object associated with the journal file instead of 8307 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8308 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8309 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8310 ** from the pager. 8311 ** 8312 ** ^If the second parameter (zDbName) does not match the name of any 8313 ** open database file, then SQLITE_ERROR is returned. ^This error 8314 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8315 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8316 ** also return SQLITE_ERROR. There is no way to distinguish between 8317 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8318 ** xFileControl method. 8319 ** 8320 ** See also: [file control opcodes] 8321 */ 8322 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8323 8324 /* 8325 ** CAPI3REF: Testing Interface 8326 ** 8327 ** ^The sqlite3_test_control() interface is used to read out internal 8328 ** state of SQLite and to inject faults into SQLite for testing 8329 ** purposes. ^The first parameter is an operation code that determines 8330 ** the number, meaning, and operation of all subsequent parameters. 8331 ** 8332 ** This interface is not for use by applications. It exists solely 8333 ** for verifying the correct operation of the SQLite library. Depending 8334 ** on how the SQLite library is compiled, this interface might not exist. 8335 ** 8336 ** The details of the operation codes, their meanings, the parameters 8337 ** they take, and what they do are all subject to change without notice. 8338 ** Unlike most of the SQLite API, this function is not guaranteed to 8339 ** operate consistently from one release to the next. 8340 */ 8341 SQLITE_API int sqlite3_test_control(int op, ...); 8342 8343 /* 8344 ** CAPI3REF: Testing Interface Operation Codes 8345 ** 8346 ** These constants are the valid operation code parameters used 8347 ** as the first argument to [sqlite3_test_control()]. 8348 ** 8349 ** These parameters and their meanings are subject to change 8350 ** without notice. These values are for testing purposes only. 8351 ** Applications should not use any of these parameters or the 8352 ** [sqlite3_test_control()] interface. 8353 */ 8354 #define SQLITE_TESTCTRL_FIRST 5 8355 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8356 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8357 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8358 #define SQLITE_TESTCTRL_FK_NO_ACTION 7 8359 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8360 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8361 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8362 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8363 #define SQLITE_TESTCTRL_ASSERT 12 8364 #define SQLITE_TESTCTRL_ALWAYS 13 8365 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8366 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8367 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8368 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8369 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8370 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8371 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8372 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8373 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8374 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8375 #define SQLITE_TESTCTRL_BYTEORDER 22 8376 #define SQLITE_TESTCTRL_ISINIT 23 8377 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8378 #define SQLITE_TESTCTRL_IMPOSTER 25 8379 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8380 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8381 #define SQLITE_TESTCTRL_PRNG_SEED 28 8382 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8383 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8384 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8385 #define SQLITE_TESTCTRL_TUNE 32 8386 #define SQLITE_TESTCTRL_LOGEST 33 8387 #define SQLITE_TESTCTRL_USELONGDOUBLE 34 8388 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */ 8389 8390 /* 8391 ** CAPI3REF: SQL Keyword Checking 8392 ** 8393 ** These routines provide access to the set of SQL language keywords 8394 ** recognized by SQLite. Applications can uses these routines to determine 8395 ** whether or not a specific identifier needs to be escaped (for example, 8396 ** by enclosing in double-quotes) so as not to confuse the parser. 8397 ** 8398 ** The sqlite3_keyword_count() interface returns the number of distinct 8399 ** keywords understood by SQLite. 8400 ** 8401 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8402 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8403 ** of bytes in the keyword into *L. The string that *Z points to is not 8404 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8405 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8406 ** or L are NULL or invalid pointers then calls to 8407 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8408 ** 8409 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8410 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8411 ** if it is and zero if not. 8412 ** 8413 ** The parser used by SQLite is forgiving. It is often possible to use 8414 ** a keyword as an identifier as long as such use does not result in a 8415 ** parsing ambiguity. For example, the statement 8416 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8417 ** creates a new table named "BEGIN" with three columns named 8418 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8419 ** using keywords as identifiers. Common techniques used to avoid keyword 8420 ** name collisions include: 8421 ** <ul> 8422 ** <li> Put all identifier names inside double-quotes. This is the official 8423 ** SQL way to escape identifier names. 8424 ** <li> Put identifier names inside [...]. This is not standard SQL, 8425 ** but it is what SQL Server does and so lots of programmers use this 8426 ** technique. 8427 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8428 ** with "Z". 8429 ** <li> Include a digit somewhere in every identifier name. 8430 ** </ul> 8431 ** 8432 ** Note that the number of keywords understood by SQLite can depend on 8433 ** compile-time options. For example, "VACUUM" is not a keyword if 8434 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8435 ** new keywords may be added to future releases of SQLite. 8436 */ 8437 SQLITE_API int sqlite3_keyword_count(void); 8438 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8439 SQLITE_API int sqlite3_keyword_check(const char*,int); 8440 8441 /* 8442 ** CAPI3REF: Dynamic String Object 8443 ** KEYWORDS: {dynamic string} 8444 ** 8445 ** An instance of the sqlite3_str object contains a dynamically-sized 8446 ** string under construction. 8447 ** 8448 ** The lifecycle of an sqlite3_str object is as follows: 8449 ** <ol> 8450 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8451 ** <li> ^Text is appended to the sqlite3_str object using various 8452 ** methods, such as [sqlite3_str_appendf()]. 8453 ** <li> ^The sqlite3_str object is destroyed and the string it created 8454 ** is returned using the [sqlite3_str_finish()] interface. 8455 ** </ol> 8456 */ 8457 typedef struct sqlite3_str sqlite3_str; 8458 8459 /* 8460 ** CAPI3REF: Create A New Dynamic String Object 8461 ** CONSTRUCTOR: sqlite3_str 8462 ** 8463 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8464 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8465 ** [sqlite3_str_new()] must be freed by a subsequent call to 8466 ** [sqlite3_str_finish(X)]. 8467 ** 8468 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8469 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8470 ** error the returned object might be a special singleton that will 8471 ** silently reject new text, always return SQLITE_NOMEM from 8472 ** [sqlite3_str_errcode()], always return 0 for 8473 ** [sqlite3_str_length()], and always return NULL from 8474 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8475 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8476 ** to any of the other [sqlite3_str] methods. 8477 ** 8478 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8479 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8480 ** length of the string contained in the [sqlite3_str] object will be 8481 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8482 ** of [SQLITE_MAX_LENGTH]. 8483 */ 8484 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8485 8486 /* 8487 ** CAPI3REF: Finalize A Dynamic String 8488 ** DESTRUCTOR: sqlite3_str 8489 ** 8490 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8491 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8492 ** that contains the constructed string. The calling application should 8493 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8494 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8495 ** errors were encountered during construction of the string. ^The 8496 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8497 ** string in [sqlite3_str] object X is zero bytes long. 8498 */ 8499 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8500 8501 /* 8502 ** CAPI3REF: Add Content To A Dynamic String 8503 ** METHOD: sqlite3_str 8504 ** 8505 ** These interfaces add content to an sqlite3_str object previously obtained 8506 ** from [sqlite3_str_new()]. 8507 ** 8508 ** ^The [sqlite3_str_appendf(X,F,...)] and 8509 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8510 ** functionality of SQLite to append formatted text onto the end of 8511 ** [sqlite3_str] object X. 8512 ** 8513 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8514 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8515 ** S must contain at least N non-zero bytes of content. To append a 8516 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8517 ** method instead. 8518 ** 8519 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8520 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8521 ** 8522 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8523 ** single-byte character C onto the end of [sqlite3_str] object X. 8524 ** ^This method can be used, for example, to add whitespace indentation. 8525 ** 8526 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8527 ** inside [sqlite3_str] object X back to zero bytes in length. 8528 ** 8529 ** These methods do not return a result code. ^If an error occurs, that fact 8530 ** is recorded in the [sqlite3_str] object and can be recovered by a 8531 ** subsequent call to [sqlite3_str_errcode(X)]. 8532 */ 8533 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8534 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8535 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8536 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8537 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8538 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8539 8540 /* 8541 ** CAPI3REF: Status Of A Dynamic String 8542 ** METHOD: sqlite3_str 8543 ** 8544 ** These interfaces return the current status of an [sqlite3_str] object. 8545 ** 8546 ** ^If any prior errors have occurred while constructing the dynamic string 8547 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8548 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8549 ** [SQLITE_NOMEM] following any out-of-memory error, or 8550 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8551 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8552 ** 8553 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8554 ** of the dynamic string under construction in [sqlite3_str] object X. 8555 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8556 ** zero-termination byte. 8557 ** 8558 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8559 ** content of the dynamic string under construction in X. The value 8560 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8561 ** and might be freed or altered by any subsequent method on the same 8562 ** [sqlite3_str] object. Applications must not used the pointer returned 8563 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8564 ** object. ^Applications may change the content of the string returned 8565 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8566 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8567 ** write any byte after any subsequent sqlite3_str method call. 8568 */ 8569 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8570 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8571 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8572 8573 /* 8574 ** CAPI3REF: SQLite Runtime Status 8575 ** 8576 ** ^These interfaces are used to retrieve runtime status information 8577 ** about the performance of SQLite, and optionally to reset various 8578 ** highwater marks. ^The first argument is an integer code for 8579 ** the specific parameter to measure. ^(Recognized integer codes 8580 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8581 ** ^The current value of the parameter is returned into *pCurrent. 8582 ** ^The highest recorded value is returned in *pHighwater. ^If the 8583 ** resetFlag is true, then the highest record value is reset after 8584 ** *pHighwater is written. ^(Some parameters do not record the highest 8585 ** value. For those parameters 8586 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8587 ** ^(Other parameters record only the highwater mark and not the current 8588 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8589 ** 8590 ** ^The sqlite3_status() and sqlite3_status64() routines return 8591 ** SQLITE_OK on success and a non-zero [error code] on failure. 8592 ** 8593 ** If either the current value or the highwater mark is too large to 8594 ** be represented by a 32-bit integer, then the values returned by 8595 ** sqlite3_status() are undefined. 8596 ** 8597 ** See also: [sqlite3_db_status()] 8598 */ 8599 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8600 SQLITE_API int sqlite3_status64( 8601 int op, 8602 sqlite3_int64 *pCurrent, 8603 sqlite3_int64 *pHighwater, 8604 int resetFlag 8605 ); 8606 8607 8608 /* 8609 ** CAPI3REF: Status Parameters 8610 ** KEYWORDS: {status parameters} 8611 ** 8612 ** These integer constants designate various run-time status parameters 8613 ** that can be returned by [sqlite3_status()]. 8614 ** 8615 ** <dl> 8616 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8617 ** <dd>This parameter is the current amount of memory checked out 8618 ** using [sqlite3_malloc()], either directly or indirectly. The 8619 ** figure includes calls made to [sqlite3_malloc()] by the application 8620 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8621 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8622 ** this parameter. The amount returned is the sum of the allocation 8623 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8624 ** 8625 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8626 ** <dd>This parameter records the largest memory allocation request 8627 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8628 ** internal equivalents). Only the value returned in the 8629 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8630 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8631 ** 8632 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8633 ** <dd>This parameter records the number of separate memory allocations 8634 ** currently checked out.</dd>)^ 8635 ** 8636 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8637 ** <dd>This parameter returns the number of pages used out of the 8638 ** [pagecache memory allocator] that was configured using 8639 ** [SQLITE_CONFIG_PAGECACHE]. The 8640 ** value returned is in pages, not in bytes.</dd>)^ 8641 ** 8642 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8643 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8644 ** <dd>This parameter returns the number of bytes of page cache 8645 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8646 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8647 ** returned value includes allocations that overflowed because they 8648 ** where too large (they were larger than the "sz" parameter to 8649 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8650 ** no space was left in the page cache.</dd>)^ 8651 ** 8652 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8653 ** <dd>This parameter records the largest memory allocation request 8654 ** handed to the [pagecache memory allocator]. Only the value returned in the 8655 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8656 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8657 ** 8658 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8659 ** <dd>No longer used.</dd> 8660 ** 8661 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8662 ** <dd>No longer used.</dd> 8663 ** 8664 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8665 ** <dd>No longer used.</dd> 8666 ** 8667 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8668 ** <dd>The *pHighwater parameter records the deepest parser stack. 8669 ** The *pCurrent value is undefined. The *pHighwater value is only 8670 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8671 ** </dl> 8672 ** 8673 ** New status parameters may be added from time to time. 8674 */ 8675 #define SQLITE_STATUS_MEMORY_USED 0 8676 #define SQLITE_STATUS_PAGECACHE_USED 1 8677 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8678 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8679 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8680 #define SQLITE_STATUS_MALLOC_SIZE 5 8681 #define SQLITE_STATUS_PARSER_STACK 6 8682 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8683 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8684 #define SQLITE_STATUS_MALLOC_COUNT 9 8685 8686 /* 8687 ** CAPI3REF: Database Connection Status 8688 ** METHOD: sqlite3 8689 ** 8690 ** ^This interface is used to retrieve runtime status information 8691 ** about a single [database connection]. ^The first argument is the 8692 ** database connection object to be interrogated. ^The second argument 8693 ** is an integer constant, taken from the set of 8694 ** [SQLITE_DBSTATUS options], that 8695 ** determines the parameter to interrogate. The set of 8696 ** [SQLITE_DBSTATUS options] is likely 8697 ** to grow in future releases of SQLite. 8698 ** 8699 ** ^The current value of the requested parameter is written into *pCur 8700 ** and the highest instantaneous value is written into *pHiwtr. ^If 8701 ** the resetFlg is true, then the highest instantaneous value is 8702 ** reset back down to the current value. 8703 ** 8704 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8705 ** non-zero [error code] on failure. 8706 ** 8707 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8708 */ 8709 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8710 8711 /* 8712 ** CAPI3REF: Status Parameters for database connections 8713 ** KEYWORDS: {SQLITE_DBSTATUS options} 8714 ** 8715 ** These constants are the available integer "verbs" that can be passed as 8716 ** the second argument to the [sqlite3_db_status()] interface. 8717 ** 8718 ** New verbs may be added in future releases of SQLite. Existing verbs 8719 ** might be discontinued. Applications should check the return code from 8720 ** [sqlite3_db_status()] to make sure that the call worked. 8721 ** The [sqlite3_db_status()] interface will return a non-zero error code 8722 ** if a discontinued or unsupported verb is invoked. 8723 ** 8724 ** <dl> 8725 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8726 ** <dd>This parameter returns the number of lookaside memory slots currently 8727 ** checked out.</dd>)^ 8728 ** 8729 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8730 ** <dd>This parameter returns the number of malloc attempts that were 8731 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8732 ** the current value is always zero.)^ 8733 ** 8734 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8735 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8736 ** <dd>This parameter returns the number malloc attempts that might have 8737 ** been satisfied using lookaside memory but failed due to the amount of 8738 ** memory requested being larger than the lookaside slot size. 8739 ** Only the high-water value is meaningful; 8740 ** the current value is always zero.)^ 8741 ** 8742 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8743 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8744 ** <dd>This parameter returns the number malloc attempts that might have 8745 ** been satisfied using lookaside memory but failed due to all lookaside 8746 ** memory already being in use. 8747 ** Only the high-water value is meaningful; 8748 ** the current value is always zero.)^ 8749 ** 8750 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8751 ** <dd>This parameter returns the approximate number of bytes of heap 8752 ** memory used by all pager caches associated with the database connection.)^ 8753 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8754 ** 8755 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8756 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8757 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8758 ** pager cache is shared between two or more connections the bytes of heap 8759 ** memory used by that pager cache is divided evenly between the attached 8760 ** connections.)^ In other words, if none of the pager caches associated 8761 ** with the database connection are shared, this request returns the same 8762 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8763 ** shared, the value returned by this call will be smaller than that returned 8764 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8765 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8766 ** 8767 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8768 ** <dd>This parameter returns the approximate number of bytes of heap 8769 ** memory used to store the schema for all databases associated 8770 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8771 ** ^The full amount of memory used by the schemas is reported, even if the 8772 ** schema memory is shared with other database connections due to 8773 ** [shared cache mode] being enabled. 8774 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8775 ** 8776 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8777 ** <dd>This parameter returns the approximate number of bytes of heap 8778 ** and lookaside memory used by all prepared statements associated with 8779 ** the database connection.)^ 8780 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8781 ** </dd> 8782 ** 8783 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8784 ** <dd>This parameter returns the number of pager cache hits that have 8785 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8786 ** is always 0. 8787 ** </dd> 8788 ** 8789 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8790 ** <dd>This parameter returns the number of pager cache misses that have 8791 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8792 ** is always 0. 8793 ** </dd> 8794 ** 8795 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8796 ** <dd>This parameter returns the number of dirty cache entries that have 8797 ** been written to disk. Specifically, the number of pages written to the 8798 ** wal file in wal mode databases, or the number of pages written to the 8799 ** database file in rollback mode databases. Any pages written as part of 8800 ** transaction rollback or database recovery operations are not included. 8801 ** If an IO or other error occurs while writing a page to disk, the effect 8802 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8803 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8804 ** </dd> 8805 ** 8806 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8807 ** <dd>This parameter returns the number of dirty cache entries that have 8808 ** been written to disk in the middle of a transaction due to the page 8809 ** cache overflowing. Transactions are more efficient if they are written 8810 ** to disk all at once. When pages spill mid-transaction, that introduces 8811 ** additional overhead. This parameter can be used help identify 8812 ** inefficiencies that can be resolved by increasing the cache size. 8813 ** </dd> 8814 ** 8815 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8816 ** <dd>This parameter returns zero for the current value if and only if 8817 ** all foreign key constraints (deferred or immediate) have been 8818 ** resolved.)^ ^The highwater mark is always 0. 8819 ** </dd> 8820 ** </dl> 8821 */ 8822 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8823 #define SQLITE_DBSTATUS_CACHE_USED 1 8824 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8825 #define SQLITE_DBSTATUS_STMT_USED 3 8826 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8827 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8828 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8829 #define SQLITE_DBSTATUS_CACHE_HIT 7 8830 #define SQLITE_DBSTATUS_CACHE_MISS 8 8831 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8832 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8833 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8834 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8835 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8836 8837 8838 /* 8839 ** CAPI3REF: Prepared Statement Status 8840 ** METHOD: sqlite3_stmt 8841 ** 8842 ** ^(Each prepared statement maintains various 8843 ** [SQLITE_STMTSTATUS counters] that measure the number 8844 ** of times it has performed specific operations.)^ These counters can 8845 ** be used to monitor the performance characteristics of the prepared 8846 ** statements. For example, if the number of table steps greatly exceeds 8847 ** the number of table searches or result rows, that would tend to indicate 8848 ** that the prepared statement is using a full table scan rather than 8849 ** an index. 8850 ** 8851 ** ^(This interface is used to retrieve and reset counter values from 8852 ** a [prepared statement]. The first argument is the prepared statement 8853 ** object to be interrogated. The second argument 8854 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8855 ** to be interrogated.)^ 8856 ** ^The current value of the requested counter is returned. 8857 ** ^If the resetFlg is true, then the counter is reset to zero after this 8858 ** interface call returns. 8859 ** 8860 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8861 */ 8862 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8863 8864 /* 8865 ** CAPI3REF: Status Parameters for prepared statements 8866 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8867 ** 8868 ** These preprocessor macros define integer codes that name counter 8869 ** values associated with the [sqlite3_stmt_status()] interface. 8870 ** The meanings of the various counters are as follows: 8871 ** 8872 ** <dl> 8873 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8874 ** <dd>^This is the number of times that SQLite has stepped forward in 8875 ** a table as part of a full table scan. Large numbers for this counter 8876 ** may indicate opportunities for performance improvement through 8877 ** careful use of indices.</dd> 8878 ** 8879 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8880 ** <dd>^This is the number of sort operations that have occurred. 8881 ** A non-zero value in this counter may indicate an opportunity to 8882 ** improvement performance through careful use of indices.</dd> 8883 ** 8884 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8885 ** <dd>^This is the number of rows inserted into transient indices that 8886 ** were created automatically in order to help joins run faster. 8887 ** A non-zero value in this counter may indicate an opportunity to 8888 ** improvement performance by adding permanent indices that do not 8889 ** need to be reinitialized each time the statement is run.</dd> 8890 ** 8891 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8892 ** <dd>^This is the number of virtual machine operations executed 8893 ** by the prepared statement if that number is less than or equal 8894 ** to 2147483647. The number of virtual machine operations can be 8895 ** used as a proxy for the total work done by the prepared statement. 8896 ** If the number of virtual machine operations exceeds 2147483647 8897 ** then the value returned by this statement status code is undefined. 8898 ** 8899 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8900 ** <dd>^This is the number of times that the prepare statement has been 8901 ** automatically regenerated due to schema changes or changes to 8902 ** [bound parameters] that might affect the query plan. 8903 ** 8904 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8905 ** <dd>^This is the number of times that the prepared statement has 8906 ** been run. A single "run" for the purposes of this counter is one 8907 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8908 ** The counter is incremented on the first [sqlite3_step()] call of each 8909 ** cycle. 8910 ** 8911 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8912 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8913 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8914 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8915 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8916 ** step was bypassed because a Bloom filter returned not-found. The 8917 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8918 ** times that the Bloom filter returned a find, and thus the join step 8919 ** had to be processed as normal. 8920 ** 8921 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8922 ** <dd>^This is the approximate number of bytes of heap memory 8923 ** used to store the prepared statement. ^This value is not actually 8924 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8925 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8926 ** </dd> 8927 ** </dl> 8928 */ 8929 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8930 #define SQLITE_STMTSTATUS_SORT 2 8931 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8932 #define SQLITE_STMTSTATUS_VM_STEP 4 8933 #define SQLITE_STMTSTATUS_REPREPARE 5 8934 #define SQLITE_STMTSTATUS_RUN 6 8935 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8936 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8937 #define SQLITE_STMTSTATUS_MEMUSED 99 8938 8939 /* 8940 ** CAPI3REF: Custom Page Cache Object 8941 ** 8942 ** The sqlite3_pcache type is opaque. It is implemented by 8943 ** the pluggable module. The SQLite core has no knowledge of 8944 ** its size or internal structure and never deals with the 8945 ** sqlite3_pcache object except by holding and passing pointers 8946 ** to the object. 8947 ** 8948 ** See [sqlite3_pcache_methods2] for additional information. 8949 */ 8950 typedef struct sqlite3_pcache sqlite3_pcache; 8951 8952 /* 8953 ** CAPI3REF: Custom Page Cache Object 8954 ** 8955 ** The sqlite3_pcache_page object represents a single page in the 8956 ** page cache. The page cache will allocate instances of this 8957 ** object. Various methods of the page cache use pointers to instances 8958 ** of this object as parameters or as their return value. 8959 ** 8960 ** See [sqlite3_pcache_methods2] for additional information. 8961 */ 8962 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8963 struct sqlite3_pcache_page { 8964 void *pBuf; /* The content of the page */ 8965 void *pExtra; /* Extra information associated with the page */ 8966 }; 8967 8968 /* 8969 ** CAPI3REF: Application Defined Page Cache. 8970 ** KEYWORDS: {page cache} 8971 ** 8972 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8973 ** register an alternative page cache implementation by passing in an 8974 ** instance of the sqlite3_pcache_methods2 structure.)^ 8975 ** In many applications, most of the heap memory allocated by 8976 ** SQLite is used for the page cache. 8977 ** By implementing a 8978 ** custom page cache using this API, an application can better control 8979 ** the amount of memory consumed by SQLite, the way in which 8980 ** that memory is allocated and released, and the policies used to 8981 ** determine exactly which parts of a database file are cached and for 8982 ** how long. 8983 ** 8984 ** The alternative page cache mechanism is an 8985 ** extreme measure that is only needed by the most demanding applications. 8986 ** The built-in page cache is recommended for most uses. 8987 ** 8988 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8989 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8990 ** the application may discard the parameter after the call to 8991 ** [sqlite3_config()] returns.)^ 8992 ** 8993 ** [[the xInit() page cache method]] 8994 ** ^(The xInit() method is called once for each effective 8995 ** call to [sqlite3_initialize()])^ 8996 ** (usually only once during the lifetime of the process). ^(The xInit() 8997 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8998 ** The intent of the xInit() method is to set up global data structures 8999 ** required by the custom page cache implementation. 9000 ** ^(If the xInit() method is NULL, then the 9001 ** built-in default page cache is used instead of the application defined 9002 ** page cache.)^ 9003 ** 9004 ** [[the xShutdown() page cache method]] 9005 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 9006 ** It can be used to clean up 9007 ** any outstanding resources before process shutdown, if required. 9008 ** ^The xShutdown() method may be NULL. 9009 ** 9010 ** ^SQLite automatically serializes calls to the xInit method, 9011 ** so the xInit method need not be threadsafe. ^The 9012 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 9013 ** not need to be threadsafe either. All other methods must be threadsafe 9014 ** in multithreaded applications. 9015 ** 9016 ** ^SQLite will never invoke xInit() more than once without an intervening 9017 ** call to xShutdown(). 9018 ** 9019 ** [[the xCreate() page cache methods]] 9020 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 9021 ** SQLite will typically create one cache instance for each open database file, 9022 ** though this is not guaranteed. ^The 9023 ** first parameter, szPage, is the size in bytes of the pages that must 9024 ** be allocated by the cache. ^szPage will always a power of two. ^The 9025 ** second parameter szExtra is a number of bytes of extra storage 9026 ** associated with each page cache entry. ^The szExtra parameter will 9027 ** a number less than 250. SQLite will use the 9028 ** extra szExtra bytes on each page to store metadata about the underlying 9029 ** database page on disk. The value passed into szExtra depends 9030 ** on the SQLite version, the target platform, and how SQLite was compiled. 9031 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 9032 ** created will be used to cache database pages of a file stored on disk, or 9033 ** false if it is used for an in-memory database. The cache implementation 9034 ** does not have to do anything special based with the value of bPurgeable; 9035 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 9036 ** never invoke xUnpin() except to deliberately delete a page. 9037 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 9038 ** false will always have the "discard" flag set to true. 9039 ** ^Hence, a cache created with bPurgeable false will 9040 ** never contain any unpinned pages. 9041 ** 9042 ** [[the xCachesize() page cache method]] 9043 ** ^(The xCachesize() method may be called at any time by SQLite to set the 9044 ** suggested maximum cache-size (number of pages stored by) the cache 9045 ** instance passed as the first argument. This is the value configured using 9046 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 9047 ** parameter, the implementation is not required to do anything with this 9048 ** value; it is advisory only. 9049 ** 9050 ** [[the xPagecount() page cache methods]] 9051 ** The xPagecount() method must return the number of pages currently 9052 ** stored in the cache, both pinned and unpinned. 9053 ** 9054 ** [[the xFetch() page cache methods]] 9055 ** The xFetch() method locates a page in the cache and returns a pointer to 9056 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 9057 ** The pBuf element of the returned sqlite3_pcache_page object will be a 9058 ** pointer to a buffer of szPage bytes used to store the content of a 9059 ** single database page. The pExtra element of sqlite3_pcache_page will be 9060 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 9061 ** for each entry in the page cache. 9062 ** 9063 ** The page to be fetched is determined by the key. ^The minimum key value 9064 ** is 1. After it has been retrieved using xFetch, the page is considered 9065 ** to be "pinned". 9066 ** 9067 ** If the requested page is already in the page cache, then the page cache 9068 ** implementation must return a pointer to the page buffer with its content 9069 ** intact. If the requested page is not already in the cache, then the 9070 ** cache implementation should use the value of the createFlag 9071 ** parameter to help it determined what action to take: 9072 ** 9073 ** <table border=1 width=85% align=center> 9074 ** <tr><th> createFlag <th> Behavior when page is not already in cache 9075 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 9076 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 9077 ** Otherwise return NULL. 9078 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 9079 ** NULL if allocating a new page is effectively impossible. 9080 ** </table> 9081 ** 9082 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 9083 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 9084 ** failed.)^ In between the xFetch() calls, SQLite may 9085 ** attempt to unpin one or more cache pages by spilling the content of 9086 ** pinned pages to disk and synching the operating system disk cache. 9087 ** 9088 ** [[the xUnpin() page cache method]] 9089 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 9090 ** as its second argument. If the third parameter, discard, is non-zero, 9091 ** then the page must be evicted from the cache. 9092 ** ^If the discard parameter is 9093 ** zero, then the page may be discarded or retained at the discretion of 9094 ** page cache implementation. ^The page cache implementation 9095 ** may choose to evict unpinned pages at any time. 9096 ** 9097 ** The cache must not perform any reference counting. A single 9098 ** call to xUnpin() unpins the page regardless of the number of prior calls 9099 ** to xFetch(). 9100 ** 9101 ** [[the xRekey() page cache methods]] 9102 ** The xRekey() method is used to change the key value associated with the 9103 ** page passed as the second argument. If the cache 9104 ** previously contains an entry associated with newKey, it must be 9105 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 9106 ** to be pinned. 9107 ** 9108 ** When SQLite calls the xTruncate() method, the cache must discard all 9109 ** existing cache entries with page numbers (keys) greater than or equal 9110 ** to the value of the iLimit parameter passed to xTruncate(). If any 9111 ** of these pages are pinned, they are implicitly unpinned, meaning that 9112 ** they can be safely discarded. 9113 ** 9114 ** [[the xDestroy() page cache method]] 9115 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 9116 ** All resources associated with the specified cache should be freed. ^After 9117 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 9118 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 9119 ** functions. 9120 ** 9121 ** [[the xShrink() page cache method]] 9122 ** ^SQLite invokes the xShrink() method when it wants the page cache to 9123 ** free up as much of heap memory as possible. The page cache implementation 9124 ** is not obligated to free any memory, but well-behaved implementations should 9125 ** do their best. 9126 */ 9127 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 9128 struct sqlite3_pcache_methods2 { 9129 int iVersion; 9130 void *pArg; 9131 int (*xInit)(void*); 9132 void (*xShutdown)(void*); 9133 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 9134 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9135 int (*xPagecount)(sqlite3_pcache*); 9136 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9137 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 9138 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 9139 unsigned oldKey, unsigned newKey); 9140 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9141 void (*xDestroy)(sqlite3_pcache*); 9142 void (*xShrink)(sqlite3_pcache*); 9143 }; 9144 9145 /* 9146 ** This is the obsolete pcache_methods object that has now been replaced 9147 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 9148 ** retained in the header file for backwards compatibility only. 9149 */ 9150 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 9151 struct sqlite3_pcache_methods { 9152 void *pArg; 9153 int (*xInit)(void*); 9154 void (*xShutdown)(void*); 9155 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 9156 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 9157 int (*xPagecount)(sqlite3_pcache*); 9158 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 9159 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 9160 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 9161 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 9162 void (*xDestroy)(sqlite3_pcache*); 9163 }; 9164 9165 9166 /* 9167 ** CAPI3REF: Online Backup Object 9168 ** 9169 ** The sqlite3_backup object records state information about an ongoing 9170 ** online backup operation. ^The sqlite3_backup object is created by 9171 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 9172 ** [sqlite3_backup_finish()]. 9173 ** 9174 ** See Also: [Using the SQLite Online Backup API] 9175 */ 9176 typedef struct sqlite3_backup sqlite3_backup; 9177 9178 /* 9179 ** CAPI3REF: Online Backup API. 9180 ** 9181 ** The backup API copies the content of one database into another. 9182 ** It is useful either for creating backups of databases or 9183 ** for copying in-memory databases to or from persistent files. 9184 ** 9185 ** See Also: [Using the SQLite Online Backup API] 9186 ** 9187 ** ^SQLite holds a write transaction open on the destination database file 9188 ** for the duration of the backup operation. 9189 ** ^The source database is read-locked only while it is being read; 9190 ** it is not locked continuously for the entire backup operation. 9191 ** ^Thus, the backup may be performed on a live source database without 9192 ** preventing other database connections from 9193 ** reading or writing to the source database while the backup is underway. 9194 ** 9195 ** ^(To perform a backup operation: 9196 ** <ol> 9197 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 9198 ** backup, 9199 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 9200 ** the data between the two databases, and finally 9201 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 9202 ** associated with the backup operation. 9203 ** </ol>)^ 9204 ** There should be exactly one call to sqlite3_backup_finish() for each 9205 ** successful call to sqlite3_backup_init(). 9206 ** 9207 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 9208 ** 9209 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 9210 ** [database connection] associated with the destination database 9211 ** and the database name, respectively. 9212 ** ^The database name is "main" for the main database, "temp" for the 9213 ** temporary database, or the name specified after the AS keyword in 9214 ** an [ATTACH] statement for an attached database. 9215 ** ^The S and M arguments passed to 9216 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 9217 ** and database name of the source database, respectively. 9218 ** ^The source and destination [database connections] (parameters S and D) 9219 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 9220 ** an error. 9221 ** 9222 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 9223 ** there is already a read or read-write transaction open on the 9224 ** destination database. 9225 ** 9226 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 9227 ** returned and an error code and error message are stored in the 9228 ** destination [database connection] D. 9229 ** ^The error code and message for the failed call to sqlite3_backup_init() 9230 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 9231 ** [sqlite3_errmsg16()] functions. 9232 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 9233 ** [sqlite3_backup] object. 9234 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 9235 ** sqlite3_backup_finish() functions to perform the specified backup 9236 ** operation. 9237 ** 9238 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 9239 ** 9240 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 9241 ** the source and destination databases specified by [sqlite3_backup] object B. 9242 ** ^If N is negative, all remaining source pages are copied. 9243 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 9244 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 9245 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9246 ** from source to destination, then it returns [SQLITE_DONE]. 9247 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9248 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9249 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9250 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9251 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9252 ** 9253 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9254 ** <ol> 9255 ** <li> the destination database was opened read-only, or 9256 ** <li> the destination database is using write-ahead-log journaling 9257 ** and the destination and source page sizes differ, or 9258 ** <li> the destination database is an in-memory database and the 9259 ** destination and source page sizes differ. 9260 ** </ol>)^ 9261 ** 9262 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9263 ** the [sqlite3_busy_handler | busy-handler function] 9264 ** is invoked (if one is specified). ^If the 9265 ** busy-handler returns non-zero before the lock is available, then 9266 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9267 ** sqlite3_backup_step() can be retried later. ^If the source 9268 ** [database connection] 9269 ** is being used to write to the source database when sqlite3_backup_step() 9270 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9271 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9272 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9273 ** [SQLITE_READONLY] is returned, then 9274 ** there is no point in retrying the call to sqlite3_backup_step(). These 9275 ** errors are considered fatal.)^ The application must accept 9276 ** that the backup operation has failed and pass the backup operation handle 9277 ** to the sqlite3_backup_finish() to release associated resources. 9278 ** 9279 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9280 ** on the destination file. ^The exclusive lock is not released until either 9281 ** sqlite3_backup_finish() is called or the backup operation is complete 9282 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9283 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9284 ** lasts for the duration of the sqlite3_backup_step() call. 9285 ** ^Because the source database is not locked between calls to 9286 ** sqlite3_backup_step(), the source database may be modified mid-way 9287 ** through the backup process. ^If the source database is modified by an 9288 ** external process or via a database connection other than the one being 9289 ** used by the backup operation, then the backup will be automatically 9290 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9291 ** database is modified by the using the same database connection as is used 9292 ** by the backup operation, then the backup database is automatically 9293 ** updated at the same time. 9294 ** 9295 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9296 ** 9297 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9298 ** application wishes to abandon the backup operation, the application 9299 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9300 ** ^The sqlite3_backup_finish() interfaces releases all 9301 ** resources associated with the [sqlite3_backup] object. 9302 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9303 ** active write-transaction on the destination database is rolled back. 9304 ** The [sqlite3_backup] object is invalid 9305 ** and may not be used following a call to sqlite3_backup_finish(). 9306 ** 9307 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9308 ** sqlite3_backup_step() errors occurred, regardless or whether or not 9309 ** sqlite3_backup_step() completed. 9310 ** ^If an out-of-memory condition or IO error occurred during any prior 9311 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9312 ** sqlite3_backup_finish() returns the corresponding [error code]. 9313 ** 9314 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9315 ** is not a permanent error and does not affect the return value of 9316 ** sqlite3_backup_finish(). 9317 ** 9318 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9319 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9320 ** 9321 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9322 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9323 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9324 ** in the source database at the conclusion of the most recent 9325 ** sqlite3_backup_step(). 9326 ** ^(The values returned by these functions are only updated by 9327 ** sqlite3_backup_step(). If the source database is modified in a way that 9328 ** changes the size of the source database or the number of pages remaining, 9329 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9330 ** and sqlite3_backup_remaining() until after the next 9331 ** sqlite3_backup_step().)^ 9332 ** 9333 ** <b>Concurrent Usage of Database Handles</b> 9334 ** 9335 ** ^The source [database connection] may be used by the application for other 9336 ** purposes while a backup operation is underway or being initialized. 9337 ** ^If SQLite is compiled and configured to support threadsafe database 9338 ** connections, then the source database connection may be used concurrently 9339 ** from within other threads. 9340 ** 9341 ** However, the application must guarantee that the destination 9342 ** [database connection] is not passed to any other API (by any thread) after 9343 ** sqlite3_backup_init() is called and before the corresponding call to 9344 ** sqlite3_backup_finish(). SQLite does not currently check to see 9345 ** if the application incorrectly accesses the destination [database connection] 9346 ** and so no error code is reported, but the operations may malfunction 9347 ** nevertheless. Use of the destination database connection while a 9348 ** backup is in progress might also cause a mutex deadlock. 9349 ** 9350 ** If running in [shared cache mode], the application must 9351 ** guarantee that the shared cache used by the destination database 9352 ** is not accessed while the backup is running. In practice this means 9353 ** that the application must guarantee that the disk file being 9354 ** backed up to is not accessed by any connection within the process, 9355 ** not just the specific connection that was passed to sqlite3_backup_init(). 9356 ** 9357 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9358 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9359 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9360 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9361 ** same time as another thread is invoking sqlite3_backup_step() it is 9362 ** possible that they return invalid values. 9363 */ 9364 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9365 sqlite3 *pDest, /* Destination database handle */ 9366 const char *zDestName, /* Destination database name */ 9367 sqlite3 *pSource, /* Source database handle */ 9368 const char *zSourceName /* Source database name */ 9369 ); 9370 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9371 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9372 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9373 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9374 9375 /* 9376 ** CAPI3REF: Unlock Notification 9377 ** METHOD: sqlite3 9378 ** 9379 ** ^When running in shared-cache mode, a database operation may fail with 9380 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9381 ** individual tables within the shared-cache cannot be obtained. See 9382 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9383 ** ^This API may be used to register a callback that SQLite will invoke 9384 ** when the connection currently holding the required lock relinquishes it. 9385 ** ^This API is only available if the library was compiled with the 9386 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9387 ** 9388 ** See Also: [Using the SQLite Unlock Notification Feature]. 9389 ** 9390 ** ^Shared-cache locks are released when a database connection concludes 9391 ** its current transaction, either by committing it or rolling it back. 9392 ** 9393 ** ^When a connection (known as the blocked connection) fails to obtain a 9394 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9395 ** identity of the database connection (the blocking connection) that 9396 ** has locked the required resource is stored internally. ^After an 9397 ** application receives an SQLITE_LOCKED error, it may call the 9398 ** sqlite3_unlock_notify() method with the blocked connection handle as 9399 ** the first argument to register for a callback that will be invoked 9400 ** when the blocking connections current transaction is concluded. ^The 9401 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9402 ** call that concludes the blocking connection's transaction. 9403 ** 9404 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9405 ** there is a chance that the blocking connection will have already 9406 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9407 ** If this happens, then the specified callback is invoked immediately, 9408 ** from within the call to sqlite3_unlock_notify().)^ 9409 ** 9410 ** ^If the blocked connection is attempting to obtain a write-lock on a 9411 ** shared-cache table, and more than one other connection currently holds 9412 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9413 ** the other connections to use as the blocking connection. 9414 ** 9415 ** ^(There may be at most one unlock-notify callback registered by a 9416 ** blocked connection. If sqlite3_unlock_notify() is called when the 9417 ** blocked connection already has a registered unlock-notify callback, 9418 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9419 ** called with a NULL pointer as its second argument, then any existing 9420 ** unlock-notify callback is canceled. ^The blocked connections 9421 ** unlock-notify callback may also be canceled by closing the blocked 9422 ** connection using [sqlite3_close()]. 9423 ** 9424 ** The unlock-notify callback is not reentrant. If an application invokes 9425 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9426 ** crash or deadlock may be the result. 9427 ** 9428 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9429 ** returns SQLITE_OK. 9430 ** 9431 ** <b>Callback Invocation Details</b> 9432 ** 9433 ** When an unlock-notify callback is registered, the application provides a 9434 ** single void* pointer that is passed to the callback when it is invoked. 9435 ** However, the signature of the callback function allows SQLite to pass 9436 ** it an array of void* context pointers. The first argument passed to 9437 ** an unlock-notify callback is a pointer to an array of void* pointers, 9438 ** and the second is the number of entries in the array. 9439 ** 9440 ** When a blocking connection's transaction is concluded, there may be 9441 ** more than one blocked connection that has registered for an unlock-notify 9442 ** callback. ^If two or more such blocked connections have specified the 9443 ** same callback function, then instead of invoking the callback function 9444 ** multiple times, it is invoked once with the set of void* context pointers 9445 ** specified by the blocked connections bundled together into an array. 9446 ** This gives the application an opportunity to prioritize any actions 9447 ** related to the set of unblocked database connections. 9448 ** 9449 ** <b>Deadlock Detection</b> 9450 ** 9451 ** Assuming that after registering for an unlock-notify callback a 9452 ** database waits for the callback to be issued before taking any further 9453 ** action (a reasonable assumption), then using this API may cause the 9454 ** application to deadlock. For example, if connection X is waiting for 9455 ** connection Y's transaction to be concluded, and similarly connection 9456 ** Y is waiting on connection X's transaction, then neither connection 9457 ** will proceed and the system may remain deadlocked indefinitely. 9458 ** 9459 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9460 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9461 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9462 ** unlock-notify callback is registered. The system is said to be in 9463 ** a deadlocked state if connection A has registered for an unlock-notify 9464 ** callback on the conclusion of connection B's transaction, and connection 9465 ** B has itself registered for an unlock-notify callback when connection 9466 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9467 ** the system is also considered to be deadlocked if connection B has 9468 ** registered for an unlock-notify callback on the conclusion of connection 9469 ** C's transaction, where connection C is waiting on connection A. ^Any 9470 ** number of levels of indirection are allowed. 9471 ** 9472 ** <b>The "DROP TABLE" Exception</b> 9473 ** 9474 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9475 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9476 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9477 ** SQLite checks if there are any currently executing SELECT statements 9478 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9479 ** returned. In this case there is no "blocking connection", so invoking 9480 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9481 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9482 ** or "DROP INDEX" query, an infinite loop might be the result. 9483 ** 9484 ** One way around this problem is to check the extended error code returned 9485 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9486 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9487 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9488 ** SQLITE_LOCKED.)^ 9489 */ 9490 SQLITE_API int sqlite3_unlock_notify( 9491 sqlite3 *pBlocked, /* Waiting connection */ 9492 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9493 void *pNotifyArg /* Argument to pass to xNotify */ 9494 ); 9495 9496 9497 /* 9498 ** CAPI3REF: String Comparison 9499 ** 9500 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9501 ** and extensions to compare the contents of two buffers containing UTF-8 9502 ** strings in a case-independent fashion, using the same definition of "case 9503 ** independence" that SQLite uses internally when comparing identifiers. 9504 */ 9505 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9506 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9507 9508 /* 9509 ** CAPI3REF: String Globbing 9510 * 9511 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9512 ** string X matches the [GLOB] pattern P. 9513 ** ^The definition of [GLOB] pattern matching used in 9514 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9515 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9516 ** is case sensitive. 9517 ** 9518 ** Note that this routine returns zero on a match and non-zero if the strings 9519 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9520 ** 9521 ** See also: [sqlite3_strlike()]. 9522 */ 9523 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9524 9525 /* 9526 ** CAPI3REF: String LIKE Matching 9527 * 9528 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9529 ** string X matches the [LIKE] pattern P with escape character E. 9530 ** ^The definition of [LIKE] pattern matching used in 9531 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9532 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9533 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9534 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9535 ** insensitive - equivalent upper and lower case ASCII characters match 9536 ** one another. 9537 ** 9538 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9539 ** only ASCII characters are case folded. 9540 ** 9541 ** Note that this routine returns zero on a match and non-zero if the strings 9542 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9543 ** 9544 ** See also: [sqlite3_strglob()]. 9545 */ 9546 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9547 9548 /* 9549 ** CAPI3REF: Error Logging Interface 9550 ** 9551 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9552 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9553 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9554 ** used with [sqlite3_snprintf()] to generate the final output string. 9555 ** 9556 ** The sqlite3_log() interface is intended for use by extensions such as 9557 ** virtual tables, collating functions, and SQL functions. While there is 9558 ** nothing to prevent an application from calling sqlite3_log(), doing so 9559 ** is considered bad form. 9560 ** 9561 ** The zFormat string must not be NULL. 9562 ** 9563 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9564 ** will not use dynamically allocated memory. The log message is stored in 9565 ** a fixed-length buffer on the stack. If the log message is longer than 9566 ** a few hundred characters, it will be truncated to the length of the 9567 ** buffer. 9568 */ 9569 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9570 9571 /* 9572 ** CAPI3REF: Write-Ahead Log Commit Hook 9573 ** METHOD: sqlite3 9574 ** 9575 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9576 ** is invoked each time data is committed to a database in wal mode. 9577 ** 9578 ** ^(The callback is invoked by SQLite after the commit has taken place and 9579 ** the associated write-lock on the database released)^, so the implementation 9580 ** may read, write or [checkpoint] the database as required. 9581 ** 9582 ** ^The first parameter passed to the callback function when it is invoked 9583 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9584 ** registering the callback. ^The second is a copy of the database handle. 9585 ** ^The third parameter is the name of the database that was written to - 9586 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9587 ** is the number of pages currently in the write-ahead log file, 9588 ** including those that were just committed. 9589 ** 9590 ** The callback function should normally return [SQLITE_OK]. ^If an error 9591 ** code is returned, that error will propagate back up through the 9592 ** SQLite code base to cause the statement that provoked the callback 9593 ** to report an error, though the commit will have still occurred. If the 9594 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9595 ** that does not correspond to any valid SQLite error code, the results 9596 ** are undefined. 9597 ** 9598 ** A single database handle may have at most a single write-ahead log callback 9599 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9600 ** previously registered write-ahead log callback. ^The return value is 9601 ** a copy of the third parameter from the previous call, if any, or 0. 9602 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9603 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9604 ** overwrite any prior [sqlite3_wal_hook()] settings. 9605 */ 9606 SQLITE_API void *sqlite3_wal_hook( 9607 sqlite3*, 9608 int(*)(void *,sqlite3*,const char*,int), 9609 void* 9610 ); 9611 9612 /* 9613 ** CAPI3REF: Configure an auto-checkpoint 9614 ** METHOD: sqlite3 9615 ** 9616 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9617 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9618 ** to automatically [checkpoint] 9619 ** after committing a transaction if there are N or 9620 ** more frames in the [write-ahead log] file. ^Passing zero or 9621 ** a negative value as the nFrame parameter disables automatic 9622 ** checkpoints entirely. 9623 ** 9624 ** ^The callback registered by this function replaces any existing callback 9625 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9626 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9627 ** configured by this function. 9628 ** 9629 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9630 ** from SQL. 9631 ** 9632 ** ^Checkpoints initiated by this mechanism are 9633 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9634 ** 9635 ** ^Every new [database connection] defaults to having the auto-checkpoint 9636 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9637 ** pages. The use of this interface 9638 ** is only necessary if the default setting is found to be suboptimal 9639 ** for a particular application. 9640 */ 9641 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9642 9643 /* 9644 ** CAPI3REF: Checkpoint a database 9645 ** METHOD: sqlite3 9646 ** 9647 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9648 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9649 ** 9650 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9651 ** [write-ahead log] for database X on [database connection] D to be 9652 ** transferred into the database file and for the write-ahead log to 9653 ** be reset. See the [checkpointing] documentation for addition 9654 ** information. 9655 ** 9656 ** This interface used to be the only way to cause a checkpoint to 9657 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9658 ** interface was added. This interface is retained for backwards 9659 ** compatibility and as a convenience for applications that need to manually 9660 ** start a callback but which do not need the full power (and corresponding 9661 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9662 */ 9663 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9664 9665 /* 9666 ** CAPI3REF: Checkpoint a database 9667 ** METHOD: sqlite3 9668 ** 9669 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9670 ** operation on database X of [database connection] D in mode M. Status 9671 ** information is written back into integers pointed to by L and C.)^ 9672 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9673 ** 9674 ** <dl> 9675 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9676 ** ^Checkpoint as many frames as possible without waiting for any database 9677 ** readers or writers to finish, then sync the database file if all frames 9678 ** in the log were checkpointed. ^The [busy-handler callback] 9679 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9680 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9681 ** if there are concurrent readers or writers. 9682 ** 9683 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9684 ** ^This mode blocks (it invokes the 9685 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9686 ** database writer and all readers are reading from the most recent database 9687 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9688 ** database file. ^This mode blocks new database writers while it is pending, 9689 ** but new database readers are allowed to continue unimpeded. 9690 ** 9691 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9692 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9693 ** that after checkpointing the log file it blocks (calls the 9694 ** [busy-handler callback]) 9695 ** until all readers are reading from the database file only. ^This ensures 9696 ** that the next writer will restart the log file from the beginning. 9697 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9698 ** database writer attempts while it is pending, but does not impede readers. 9699 ** 9700 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9701 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9702 ** addition that it also truncates the log file to zero bytes just prior 9703 ** to a successful return. 9704 ** </dl> 9705 ** 9706 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9707 ** the log file or to -1 if the checkpoint could not run because 9708 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9709 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9710 ** log file (including any that were already checkpointed before the function 9711 ** was called) or to -1 if the checkpoint could not run due to an error or 9712 ** because the database is not in WAL mode. ^Note that upon successful 9713 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9714 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9715 ** 9716 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9717 ** any other process is running a checkpoint operation at the same time, the 9718 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9719 ** busy-handler configured, it will not be invoked in this case. 9720 ** 9721 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9722 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9723 ** obtained immediately, and a busy-handler is configured, it is invoked and 9724 ** the writer lock retried until either the busy-handler returns 0 or the lock 9725 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9726 ** database readers as described above. ^If the busy-handler returns 0 before 9727 ** the writer lock is obtained or while waiting for database readers, the 9728 ** checkpoint operation proceeds from that point in the same way as 9729 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9730 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9731 ** 9732 ** ^If parameter zDb is NULL or points to a zero length string, then the 9733 ** specified operation is attempted on all WAL databases [attached] to 9734 ** [database connection] db. In this case the 9735 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9736 ** an SQLITE_BUSY error is encountered when processing one or more of the 9737 ** attached WAL databases, the operation is still attempted on any remaining 9738 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9739 ** error occurs while processing an attached database, processing is abandoned 9740 ** and the error code is returned to the caller immediately. ^If no error 9741 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9742 ** databases, SQLITE_OK is returned. 9743 ** 9744 ** ^If database zDb is the name of an attached database that is not in WAL 9745 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9746 ** zDb is not NULL (or a zero length string) and is not the name of any 9747 ** attached database, SQLITE_ERROR is returned to the caller. 9748 ** 9749 ** ^Unless it returns SQLITE_MISUSE, 9750 ** the sqlite3_wal_checkpoint_v2() interface 9751 ** sets the error information that is queried by 9752 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9753 ** 9754 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9755 ** from SQL. 9756 */ 9757 SQLITE_API int sqlite3_wal_checkpoint_v2( 9758 sqlite3 *db, /* Database handle */ 9759 const char *zDb, /* Name of attached database (or NULL) */ 9760 int eMode, /* SQLITE_CHECKPOINT_* value */ 9761 int *pnLog, /* OUT: Size of WAL log in frames */ 9762 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9763 ); 9764 9765 /* 9766 ** CAPI3REF: Checkpoint Mode Values 9767 ** KEYWORDS: {checkpoint mode} 9768 ** 9769 ** These constants define all valid values for the "checkpoint mode" passed 9770 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9771 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9772 ** meaning of each of these checkpoint modes. 9773 */ 9774 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9775 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9776 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9777 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9778 9779 /* 9780 ** CAPI3REF: Virtual Table Interface Configuration 9781 ** 9782 ** This function may be called by either the [xConnect] or [xCreate] method 9783 ** of a [virtual table] implementation to configure 9784 ** various facets of the virtual table interface. 9785 ** 9786 ** If this interface is invoked outside the context of an xConnect or 9787 ** xCreate virtual table method then the behavior is undefined. 9788 ** 9789 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9790 ** [database connection] in which the virtual table is being created and 9791 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9792 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9793 ** of the [virtual table configuration options]. The presence and meaning 9794 ** of parameters after C depend on which [virtual table configuration option] 9795 ** is used. 9796 */ 9797 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9798 9799 /* 9800 ** CAPI3REF: Virtual Table Configuration Options 9801 ** KEYWORDS: {virtual table configuration options} 9802 ** KEYWORDS: {virtual table configuration option} 9803 ** 9804 ** These macros define the various options to the 9805 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9806 ** can use to customize and optimize their behavior. 9807 ** 9808 ** <dl> 9809 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9810 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9811 ** <dd>Calls of the form 9812 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9813 ** where X is an integer. If X is zero, then the [virtual table] whose 9814 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9815 ** support constraints. In this configuration (which is the default) if 9816 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9817 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9818 ** specified as part of the users SQL statement, regardless of the actual 9819 ** ON CONFLICT mode specified. 9820 ** 9821 ** If X is non-zero, then the virtual table implementation guarantees 9822 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9823 ** any modifications to internal or persistent data structures have been made. 9824 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9825 ** is able to roll back a statement or database transaction, and abandon 9826 ** or continue processing the current SQL statement as appropriate. 9827 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9828 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9829 ** had been ABORT. 9830 ** 9831 ** Virtual table implementations that are required to handle OR REPLACE 9832 ** must do so within the [xUpdate] method. If a call to the 9833 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9834 ** CONFLICT policy is REPLACE, the virtual table implementation should 9835 ** silently replace the appropriate rows within the xUpdate callback and 9836 ** return SQLITE_OK. Or, if this is not possible, it may return 9837 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9838 ** constraint handling. 9839 ** </dd> 9840 ** 9841 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9842 ** <dd>Calls of the form 9843 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9844 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9845 ** prohibits that virtual table from being used from within triggers and 9846 ** views. 9847 ** </dd> 9848 ** 9849 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9850 ** <dd>Calls of the form 9851 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9852 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9853 ** identify that virtual table as being safe to use from within triggers 9854 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9855 ** virtual table can do no serious harm even if it is controlled by a 9856 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9857 ** flag unless absolutely necessary. 9858 ** </dd> 9859 ** 9860 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt> 9861 ** <dd>Calls of the form 9862 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the 9863 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation 9864 ** instruct the query planner to begin at least a read transaction on 9865 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the 9866 ** virtual table is used. 9867 ** </dd> 9868 ** </dl> 9869 */ 9870 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9871 #define SQLITE_VTAB_INNOCUOUS 2 9872 #define SQLITE_VTAB_DIRECTONLY 3 9873 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4 9874 9875 /* 9876 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9877 ** 9878 ** This function may only be called from within a call to the [xUpdate] method 9879 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9880 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9881 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9882 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9883 ** [virtual table]. 9884 */ 9885 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9886 9887 /* 9888 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9889 ** 9890 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9891 ** method of a [virtual table], then it might return true if the 9892 ** column is being fetched as part of an UPDATE operation during which the 9893 ** column value will not change. The virtual table implementation can use 9894 ** this hint as permission to substitute a return value that is less 9895 ** expensive to compute and that the corresponding 9896 ** [xUpdate] method understands as a "no-change" value. 9897 ** 9898 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9899 ** the column is not changed by the UPDATE statement, then the xColumn 9900 ** method can optionally return without setting a result, without calling 9901 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9902 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9903 ** same column in the [xUpdate] method. 9904 ** 9905 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9906 ** implementations should continue to give a correct answer even if the 9907 ** sqlite3_vtab_nochange() interface were to always return false. In the 9908 ** current implementation, the sqlite3_vtab_nochange() interface does always 9909 ** returns false for the enhanced [UPDATE FROM] statement. 9910 */ 9911 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9912 9913 /* 9914 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9915 ** METHOD: sqlite3_index_info 9916 ** 9917 ** This function may only be called from within a call to the [xBestIndex] 9918 ** method of a [virtual table]. This function returns a pointer to a string 9919 ** that is the name of the appropriate collation sequence to use for text 9920 ** comparisons on the constraint identified by its arguments. 9921 ** 9922 ** The first argument must be the pointer to the [sqlite3_index_info] object 9923 ** that is the first parameter to the xBestIndex() method. The second argument 9924 ** must be an index into the aConstraint[] array belonging to the 9925 ** sqlite3_index_info structure passed to xBestIndex. 9926 ** 9927 ** Important: 9928 ** The first parameter must be the same pointer that is passed into the 9929 ** xBestMethod() method. The first parameter may not be a pointer to a 9930 ** different [sqlite3_index_info] object, even an exact copy. 9931 ** 9932 ** The return value is computed as follows: 9933 ** 9934 ** <ol> 9935 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9936 ** a [COLLATE operator], then the name of the collation specified by 9937 ** that COLLATE operator is returned. 9938 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9939 ** of the constraint specifies an alternative collating sequence via 9940 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9941 ** statement that was passed into [sqlite3_declare_vtab()], then the 9942 ** name of that alternative collating sequence is returned. 9943 ** <li><p> Otherwise, "BINARY" is returned. 9944 ** </ol> 9945 */ 9946 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9947 9948 /* 9949 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9950 ** METHOD: sqlite3_index_info 9951 ** 9952 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9953 ** of a [virtual table] implementation. The result of calling this 9954 ** interface from outside of xBestIndex() is undefined and probably harmful. 9955 ** 9956 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9957 ** 3. The integer returned by sqlite3_vtab_distinct() 9958 ** gives the virtual table additional information about how the query 9959 ** planner wants the output to be ordered. As long as the virtual table 9960 ** can meet the ordering requirements of the query planner, it may set 9961 ** the "orderByConsumed" flag. 9962 ** 9963 ** <ol><li value="0"><p> 9964 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9965 ** that the query planner needs the virtual table to return all rows in the 9966 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9967 ** [sqlite3_index_info] object. This is the default expectation. If the 9968 ** virtual table outputs all rows in sorted order, then it is always safe for 9969 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9970 ** the return value from sqlite3_vtab_distinct(). 9971 ** <li value="1"><p> 9972 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9973 ** that the query planner does not need the rows to be returned in sorted order 9974 ** as long as all rows with the same values in all columns identified by the 9975 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9976 ** is doing a GROUP BY. 9977 ** <li value="2"><p> 9978 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9979 ** that the query planner does not need the rows returned in any particular 9980 ** order, as long as rows with the same values in all "aOrderBy" columns 9981 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9982 ** combination of values in the columns identified by the "aOrderBy" field 9983 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9984 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9985 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9986 ** that have the same value for all columns identified by "aOrderBy". 9987 ** ^However omitting the extra rows is optional. 9988 ** This mode is used for a DISTINCT query. 9989 ** <li value="3"><p> 9990 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9991 ** that the query planner needs only distinct rows but it does need the 9992 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9993 ** rows that are identical in all aOrderBy columns, if it wants to, but 9994 ** it is not required to omit any rows. This mode is used for queries 9995 ** that have both DISTINCT and ORDER BY clauses. 9996 ** </ol> 9997 ** 9998 ** ^For the purposes of comparing virtual table output values to see if the 9999 ** values are same value for sorting purposes, two NULL values are considered 10000 ** to be the same. In other words, the comparison operator is "IS" 10001 ** (or "IS NOT DISTINCT FROM") and not "==". 10002 ** 10003 ** If a virtual table implementation is unable to meet the requirements 10004 ** specified above, then it must not set the "orderByConsumed" flag in the 10005 ** [sqlite3_index_info] object or an incorrect answer may result. 10006 ** 10007 ** ^A virtual table implementation is always free to return rows in any order 10008 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 10009 ** the "orderByConsumed" flag is unset, the query planner will add extra 10010 ** [bytecode] to ensure that the final results returned by the SQL query are 10011 ** ordered correctly. The use of the "orderByConsumed" flag and the 10012 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 10013 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 10014 ** flag might help queries against a virtual table to run faster. Being 10015 ** overly aggressive and setting the "orderByConsumed" flag when it is not 10016 ** valid to do so, on the other hand, might cause SQLite to return incorrect 10017 ** results. 10018 */ 10019 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 10020 10021 /* 10022 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 10023 ** 10024 ** This interface may only be used from within an 10025 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 10026 ** The result of invoking this interface from any other context is 10027 ** undefined and probably harmful. 10028 ** 10029 ** ^(A constraint on a virtual table of the form 10030 ** "[IN operator|column IN (...)]" is 10031 ** communicated to the xBestIndex method as a 10032 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 10033 ** this constraint, it must set the corresponding 10034 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under 10035 ** the usual mode of handling IN operators, SQLite generates [bytecode] 10036 ** that invokes the [xFilter|xFilter() method] once for each value 10037 ** on the right-hand side of the IN operator.)^ Thus the virtual table 10038 ** only sees a single value from the right-hand side of the IN operator 10039 ** at a time. 10040 ** 10041 ** In some cases, however, it would be advantageous for the virtual 10042 ** table to see all values on the right-hand of the IN operator all at 10043 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 10044 ** 10045 ** <ol> 10046 ** <li><p> 10047 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 10048 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 10049 ** is an [IN operator] that can be processed all at once. ^In other words, 10050 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 10051 ** by which the virtual table can ask SQLite if all-at-once processing 10052 ** of the IN operator is even possible. 10053 ** 10054 ** <li><p> 10055 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 10056 ** to SQLite that the virtual table does or does not want to process 10057 ** the IN operator all-at-once, respectively. ^Thus when the third 10058 ** parameter (F) is non-negative, this interface is the mechanism by 10059 ** which the virtual table tells SQLite how it wants to process the 10060 ** IN operator. 10061 ** </ol> 10062 ** 10063 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 10064 ** within the same xBestIndex method call. ^For any given P,N pair, 10065 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 10066 ** within the same xBestIndex call. ^If the interface returns true 10067 ** (non-zero), that means that the constraint is an IN operator 10068 ** that can be processed all-at-once. ^If the constraint is not an IN 10069 ** operator or cannot be processed all-at-once, then the interface returns 10070 ** false. 10071 ** 10072 ** ^(All-at-once processing of the IN operator is selected if both of the 10073 ** following conditions are met: 10074 ** 10075 ** <ol> 10076 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 10077 ** integer. This is how the virtual table tells SQLite that it wants to 10078 ** use the N-th constraint. 10079 ** 10080 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 10081 ** non-negative had F>=1. 10082 ** </ol>)^ 10083 ** 10084 ** ^If either or both of the conditions above are false, then SQLite uses 10085 ** the traditional one-at-a-time processing strategy for the IN constraint. 10086 ** ^If both conditions are true, then the argvIndex-th parameter to the 10087 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 10088 ** but which can be passed to [sqlite3_vtab_in_first()] and 10089 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 10090 ** of the IN constraint. 10091 */ 10092 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 10093 10094 /* 10095 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 10096 ** 10097 ** These interfaces are only useful from within the 10098 ** [xFilter|xFilter() method] of a [virtual table] implementation. 10099 ** The result of invoking these interfaces from any other context 10100 ** is undefined and probably harmful. 10101 ** 10102 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 10103 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the 10104 ** xFilter method which invokes these routines, and specifically 10105 ** a parameter that was previously selected for all-at-once IN constraint 10106 ** processing use the [sqlite3_vtab_in()] interface in the 10107 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 10108 ** an xFilter argument that was selected for all-at-once IN constraint 10109 ** processing, then these routines return [SQLITE_ERROR].)^ 10110 ** 10111 ** ^(Use these routines to access all values on the right-hand side 10112 ** of the IN constraint using code like the following: 10113 ** 10114 ** <blockquote><pre> 10115 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 10116 ** rc==SQLITE_OK && pVal; 10117 ** rc=sqlite3_vtab_in_next(pList, &pVal) 10118 ** ){ 10119 ** // do something with pVal 10120 ** } 10121 ** if( rc!=SQLITE_OK ){ 10122 ** // an error has occurred 10123 ** } 10124 ** </pre></blockquote>)^ 10125 ** 10126 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 10127 ** routines return SQLITE_OK and set *P to point to the first or next value 10128 ** on the RHS of the IN constraint. ^If there are no more values on the 10129 ** right hand side of the IN constraint, then *P is set to NULL and these 10130 ** routines return [SQLITE_DONE]. ^The return value might be 10131 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 10132 ** 10133 ** The *ppOut values returned by these routines are only valid until the 10134 ** next call to either of these routines or until the end of the xFilter 10135 ** method from which these routines were called. If the virtual table 10136 ** implementation needs to retain the *ppOut values for longer, it must make 10137 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 10138 */ 10139 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 10140 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 10141 10142 /* 10143 ** CAPI3REF: Constraint values in xBestIndex() 10144 ** METHOD: sqlite3_index_info 10145 ** 10146 ** This API may only be used from within the [xBestIndex|xBestIndex method] 10147 ** of a [virtual table] implementation. The result of calling this interface 10148 ** from outside of an xBestIndex method are undefined and probably harmful. 10149 ** 10150 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 10151 ** the [xBestIndex] method of a [virtual table] implementation, with P being 10152 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 10153 ** J being a 0-based index into P->aConstraint[], then this routine 10154 ** attempts to set *V to the value of the right-hand operand of 10155 ** that constraint if the right-hand operand is known. ^If the 10156 ** right-hand operand is not known, then *V is set to a NULL pointer. 10157 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 10158 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 10159 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 10160 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 10161 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 10162 ** something goes wrong. 10163 ** 10164 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 10165 ** the right-hand operand of a constraint is a literal value in the original 10166 ** SQL statement. If the right-hand operand is an expression or a reference 10167 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 10168 ** will probably return [SQLITE_NOTFOUND]. 10169 ** 10170 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 10171 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 10172 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 10173 ** 10174 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 10175 ** and remains valid for the duration of the xBestIndex method call. 10176 ** ^When xBestIndex returns, the sqlite3_value object returned by 10177 ** sqlite3_vtab_rhs_value() is automatically deallocated. 10178 ** 10179 ** The "_rhs_" in the name of this routine is an abbreviation for 10180 ** "Right-Hand Side". 10181 */ 10182 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 10183 10184 /* 10185 ** CAPI3REF: Conflict resolution modes 10186 ** KEYWORDS: {conflict resolution mode} 10187 ** 10188 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 10189 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 10190 ** is for the SQL statement being evaluated. 10191 ** 10192 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 10193 ** return value from the [sqlite3_set_authorizer()] callback and that 10194 ** [SQLITE_ABORT] is also a [result code]. 10195 */ 10196 #define SQLITE_ROLLBACK 1 10197 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 10198 #define SQLITE_FAIL 3 10199 /* #define SQLITE_ABORT 4 // Also an error code */ 10200 #define SQLITE_REPLACE 5 10201 10202 /* 10203 ** CAPI3REF: Prepared Statement Scan Status Opcodes 10204 ** KEYWORDS: {scanstatus options} 10205 ** 10206 ** The following constants can be used for the T parameter to the 10207 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 10208 ** different metric for sqlite3_stmt_scanstatus() to return. 10209 ** 10210 ** When the value returned to V is a string, space to hold that string is 10211 ** managed by the prepared statement S and will be automatically freed when 10212 ** S is finalized. 10213 ** 10214 ** Not all values are available for all query elements. When a value is 10215 ** not available, the output variable is set to -1 if the value is numeric, 10216 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME). 10217 ** 10218 ** <dl> 10219 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 10220 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 10221 ** set to the total number of times that the X-th loop has run.</dd> 10222 ** 10223 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 10224 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 10225 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 10226 ** 10227 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 10228 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 10229 ** query planner's estimate for the average number of rows output from each 10230 ** iteration of the X-th loop. If the query planner's estimates was accurate, 10231 ** then this value will approximate the quotient NVISIT/NLOOP and the 10232 ** product of this value for all prior loops with the same SELECTID will 10233 ** be the NLOOP value for the current loop. 10234 ** 10235 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 10236 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10237 ** to a zero-terminated UTF-8 string containing the name of the index or table 10238 ** used for the X-th loop. 10239 ** 10240 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 10241 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 10242 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 10243 ** description for the X-th loop. 10244 ** 10245 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt> 10246 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 10247 ** id for the X-th query plan element. The id value is unique within the 10248 ** statement. The select-id is the same value as is output in the first 10249 ** column of an [EXPLAIN QUERY PLAN] query. 10250 ** 10251 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt> 10252 ** <dd>The "int" variable pointed to by the V parameter will be set to the 10253 ** the id of the parent of the current query element, if applicable, or 10254 ** to zero if the query element has no parent. This is the same value as 10255 ** returned in the second column of an [EXPLAIN QUERY PLAN] query. 10256 ** 10257 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt> 10258 ** <dd>The sqlite3_int64 output value is set to the number of cycles, 10259 ** according to the processor time-stamp counter, that elapsed while the 10260 ** query element was being processed. This value is not available for 10261 ** all query elements - if it is unavailable the output variable is 10262 ** set to -1. 10263 ** </dl> 10264 */ 10265 #define SQLITE_SCANSTAT_NLOOP 0 10266 #define SQLITE_SCANSTAT_NVISIT 1 10267 #define SQLITE_SCANSTAT_EST 2 10268 #define SQLITE_SCANSTAT_NAME 3 10269 #define SQLITE_SCANSTAT_EXPLAIN 4 10270 #define SQLITE_SCANSTAT_SELECTID 5 10271 #define SQLITE_SCANSTAT_PARENTID 6 10272 #define SQLITE_SCANSTAT_NCYCLE 7 10273 10274 /* 10275 ** CAPI3REF: Prepared Statement Scan Status 10276 ** METHOD: sqlite3_stmt 10277 ** 10278 ** These interfaces return information about the predicted and measured 10279 ** performance for pStmt. Advanced applications can use this 10280 ** interface to compare the predicted and the measured performance and 10281 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10282 ** 10283 ** Since this interface is expected to be rarely used, it is only 10284 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10285 ** compile-time option. 10286 ** 10287 ** The "iScanStatusOp" parameter determines which status information to return. 10288 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10289 ** of this interface is undefined. ^The requested measurement is written into 10290 ** a variable pointed to by the "pOut" parameter. 10291 ** 10292 ** The "flags" parameter must be passed a mask of flags. At present only 10293 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX 10294 ** is specified, then status information is available for all elements 10295 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If 10296 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements 10297 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of 10298 ** the EXPLAIN QUERY PLAN output) are available. Invoking API 10299 ** sqlite3_stmt_scanstatus() is equivalent to calling 10300 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter. 10301 ** 10302 ** Parameter "idx" identifies the specific query element to retrieve statistics 10303 ** for. Query elements are numbered starting from zero. A value of -1 may be 10304 ** to query for statistics regarding the entire query. ^If idx is out of range 10305 ** - less than -1 or greater than or equal to the total number of query 10306 ** elements used to implement the statement - a non-zero value is returned and 10307 ** the variable that pOut points to is unchanged. 10308 ** 10309 ** See also: [sqlite3_stmt_scanstatus_reset()] 10310 */ 10311 SQLITE_API int sqlite3_stmt_scanstatus( 10312 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10313 int idx, /* Index of loop to report on */ 10314 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10315 void *pOut /* Result written here */ 10316 ); 10317 SQLITE_API int sqlite3_stmt_scanstatus_v2( 10318 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10319 int idx, /* Index of loop to report on */ 10320 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10321 int flags, /* Mask of flags defined below */ 10322 void *pOut /* Result written here */ 10323 ); 10324 10325 /* 10326 ** CAPI3REF: Prepared Statement Scan Status 10327 ** KEYWORDS: {scan status flags} 10328 */ 10329 #define SQLITE_SCANSTAT_COMPLEX 0x0001 10330 10331 /* 10332 ** CAPI3REF: Zero Scan-Status Counters 10333 ** METHOD: sqlite3_stmt 10334 ** 10335 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10336 ** 10337 ** This API is only available if the library is built with pre-processor 10338 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10339 */ 10340 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10341 10342 /* 10343 ** CAPI3REF: Flush caches to disk mid-transaction 10344 ** METHOD: sqlite3 10345 ** 10346 ** ^If a write-transaction is open on [database connection] D when the 10347 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 10348 ** pages in the pager-cache that are not currently in use are written out 10349 ** to disk. A dirty page may be in use if a database cursor created by an 10350 ** active SQL statement is reading from it, or if it is page 1 of a database 10351 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10352 ** interface flushes caches for all schemas - "main", "temp", and 10353 ** any [attached] databases. 10354 ** 10355 ** ^If this function needs to obtain extra database locks before dirty pages 10356 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10357 ** immediately and there is a busy-handler callback configured, it is invoked 10358 ** in the usual manner. ^If the required lock still cannot be obtained, then 10359 ** the database is skipped and an attempt made to flush any dirty pages 10360 ** belonging to the next (if any) database. ^If any databases are skipped 10361 ** because locks cannot be obtained, but no other error occurs, this 10362 ** function returns SQLITE_BUSY. 10363 ** 10364 ** ^If any other error occurs while flushing dirty pages to disk (for 10365 ** example an IO error or out-of-memory condition), then processing is 10366 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10367 ** 10368 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10369 ** 10370 ** ^This function does not set the database handle error code or message 10371 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10372 */ 10373 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10374 10375 /* 10376 ** CAPI3REF: The pre-update hook. 10377 ** METHOD: sqlite3 10378 ** 10379 ** ^These interfaces are only available if SQLite is compiled using the 10380 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10381 ** 10382 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10383 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10384 ** on a database table. 10385 ** ^At most one preupdate hook may be registered at a time on a single 10386 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10387 ** the previous setting. 10388 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10389 ** with a NULL pointer as the second parameter. 10390 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10391 ** the first parameter to callbacks. 10392 ** 10393 ** ^The preupdate hook only fires for changes to real database tables; the 10394 ** preupdate hook is not invoked for changes to [virtual tables] or to 10395 ** system tables like sqlite_sequence or sqlite_stat1. 10396 ** 10397 ** ^The second parameter to the preupdate callback is a pointer to 10398 ** the [database connection] that registered the preupdate hook. 10399 ** ^The third parameter to the preupdate callback is one of the constants 10400 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10401 ** kind of update operation that is about to occur. 10402 ** ^(The fourth parameter to the preupdate callback is the name of the 10403 ** database within the database connection that is being modified. This 10404 ** will be "main" for the main database or "temp" for TEMP tables or 10405 ** the name given after the AS keyword in the [ATTACH] statement for attached 10406 ** databases.)^ 10407 ** ^The fifth parameter to the preupdate callback is the name of the 10408 ** table that is being modified. 10409 ** 10410 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10411 ** parameter passed to the preupdate callback is the initial [rowid] of the 10412 ** row being modified or deleted. For an INSERT operation on a rowid table, 10413 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10414 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10415 ** seventh parameter is the final rowid value of the row being inserted 10416 ** or updated. The value of the seventh parameter passed to the callback 10417 ** function is not defined for operations on WITHOUT ROWID tables, or for 10418 ** DELETE operations on rowid tables. 10419 ** 10420 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from 10421 ** the previous call on the same [database connection] D, or NULL for 10422 ** the first call on D. 10423 ** 10424 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10425 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10426 ** provide additional information about a preupdate event. These routines 10427 ** may only be called from within a preupdate callback. Invoking any of 10428 ** these routines from outside of a preupdate callback or with a 10429 ** [database connection] pointer that is different from the one supplied 10430 ** to the preupdate callback results in undefined and probably undesirable 10431 ** behavior. 10432 ** 10433 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10434 ** in the row that is being inserted, updated, or deleted. 10435 ** 10436 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10437 ** a [protected sqlite3_value] that contains the value of the Nth column of 10438 ** the table row before it is updated. The N parameter must be between 0 10439 ** and one less than the number of columns or the behavior will be 10440 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10441 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10442 ** behavior is undefined. The [sqlite3_value] that P points to 10443 ** will be destroyed when the preupdate callback returns. 10444 ** 10445 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10446 ** a [protected sqlite3_value] that contains the value of the Nth column of 10447 ** the table row after it is updated. The N parameter must be between 0 10448 ** and one less than the number of columns or the behavior will be 10449 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10450 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10451 ** behavior is undefined. The [sqlite3_value] that P points to 10452 ** will be destroyed when the preupdate callback returns. 10453 ** 10454 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10455 ** callback was invoked as a result of a direct insert, update, or delete 10456 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10457 ** triggers; or 2 for changes resulting from triggers called by top-level 10458 ** triggers; and so forth. 10459 ** 10460 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10461 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10462 ** in this case the new values are not available. In this case, when a 10463 ** callback made with op==SQLITE_DELETE is actually a write using the 10464 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10465 ** the index of the column being written. In other cases, where the 10466 ** pre-update hook is being invoked for some other reason, including a 10467 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10468 ** 10469 ** See also: [sqlite3_update_hook()] 10470 */ 10471 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10472 SQLITE_API void *sqlite3_preupdate_hook( 10473 sqlite3 *db, 10474 void(*xPreUpdate)( 10475 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10476 sqlite3 *db, /* Database handle */ 10477 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10478 char const *zDb, /* Database name */ 10479 char const *zName, /* Table name */ 10480 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10481 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10482 ), 10483 void* 10484 ); 10485 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10486 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10487 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10488 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10489 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10490 #endif 10491 10492 /* 10493 ** CAPI3REF: Low-level system error code 10494 ** METHOD: sqlite3 10495 ** 10496 ** ^Attempt to return the underlying operating system error code or error 10497 ** number that caused the most recent I/O error or failure to open a file. 10498 ** The return value is OS-dependent. For example, on unix systems, after 10499 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10500 ** called to get back the underlying "errno" that caused the problem, such 10501 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10502 */ 10503 SQLITE_API int sqlite3_system_errno(sqlite3*); 10504 10505 /* 10506 ** CAPI3REF: Database Snapshot 10507 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10508 ** 10509 ** An instance of the snapshot object records the state of a [WAL mode] 10510 ** database for some specific point in history. 10511 ** 10512 ** In [WAL mode], multiple [database connections] that are open on the 10513 ** same database file can each be reading a different historical version 10514 ** of the database file. When a [database connection] begins a read 10515 ** transaction, that connection sees an unchanging copy of the database 10516 ** as it existed for the point in time when the transaction first started. 10517 ** Subsequent changes to the database from other connections are not seen 10518 ** by the reader until a new read transaction is started. 10519 ** 10520 ** The sqlite3_snapshot object records state information about an historical 10521 ** version of the database file so that it is possible to later open a new read 10522 ** transaction that sees that historical version of the database rather than 10523 ** the most recent version. 10524 */ 10525 typedef struct sqlite3_snapshot { 10526 unsigned char hidden[48]; 10527 } sqlite3_snapshot; 10528 10529 /* 10530 ** CAPI3REF: Record A Database Snapshot 10531 ** CONSTRUCTOR: sqlite3_snapshot 10532 ** 10533 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10534 ** new [sqlite3_snapshot] object that records the current state of 10535 ** schema S in database connection D. ^On success, the 10536 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10537 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10538 ** If there is not already a read-transaction open on schema S when 10539 ** this function is called, one is opened automatically. 10540 ** 10541 ** The following must be true for this function to succeed. If any of 10542 ** the following statements are false when sqlite3_snapshot_get() is 10543 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10544 ** in this case. 10545 ** 10546 ** <ul> 10547 ** <li> The database handle must not be in [autocommit mode]. 10548 ** 10549 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10550 ** 10551 ** <li> There must not be a write transaction open on schema S of database 10552 ** connection D. 10553 ** 10554 ** <li> One or more transactions must have been written to the current wal 10555 ** file since it was created on disk (by any connection). This means 10556 ** that a snapshot cannot be taken on a wal mode database with no wal 10557 ** file immediately after it is first opened. At least one transaction 10558 ** must be written to it first. 10559 ** </ul> 10560 ** 10561 ** This function may also return SQLITE_NOMEM. If it is called with the 10562 ** database handle in autocommit mode but fails for some other reason, 10563 ** whether or not a read transaction is opened on schema S is undefined. 10564 ** 10565 ** The [sqlite3_snapshot] object returned from a successful call to 10566 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10567 ** to avoid a memory leak. 10568 ** 10569 ** The [sqlite3_snapshot_get()] interface is only available when the 10570 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10571 */ 10572 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10573 sqlite3 *db, 10574 const char *zSchema, 10575 sqlite3_snapshot **ppSnapshot 10576 ); 10577 10578 /* 10579 ** CAPI3REF: Start a read transaction on an historical snapshot 10580 ** METHOD: sqlite3_snapshot 10581 ** 10582 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10583 ** transaction or upgrades an existing one for schema S of 10584 ** [database connection] D such that the read transaction refers to 10585 ** historical [snapshot] P, rather than the most recent change to the 10586 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10587 ** on success or an appropriate [error code] if it fails. 10588 ** 10589 ** ^In order to succeed, the database connection must not be in 10590 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10591 ** is already a read transaction open on schema S, then the database handle 10592 ** must have no active statements (SELECT statements that have been passed 10593 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10594 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10595 ** if schema S does not exist, or if the snapshot object is invalid. 10596 ** 10597 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10598 ** snapshot has been overwritten by a [checkpoint]. In this case 10599 ** SQLITE_ERROR_SNAPSHOT is returned. 10600 ** 10601 ** If there is already a read transaction open when this function is 10602 ** invoked, then the same read transaction remains open (on the same 10603 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10604 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10605 ** SQLITE_IOERR error code - is returned, then the final state of the 10606 ** read transaction is undefined. If SQLITE_OK is returned, then the 10607 ** read transaction is now open on database snapshot P. 10608 ** 10609 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10610 ** database connection D does not know that the database file for 10611 ** schema S is in [WAL mode]. A database connection might not know 10612 ** that the database file is in [WAL mode] if there has been no prior 10613 ** I/O on that database connection, or if the database entered [WAL mode] 10614 ** after the most recent I/O on the database connection.)^ 10615 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10616 ** database connection in order to make it ready to use snapshots.) 10617 ** 10618 ** The [sqlite3_snapshot_open()] interface is only available when the 10619 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10620 */ 10621 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10622 sqlite3 *db, 10623 const char *zSchema, 10624 sqlite3_snapshot *pSnapshot 10625 ); 10626 10627 /* 10628 ** CAPI3REF: Destroy a snapshot 10629 ** DESTRUCTOR: sqlite3_snapshot 10630 ** 10631 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10632 ** The application must eventually free every [sqlite3_snapshot] object 10633 ** using this routine to avoid a memory leak. 10634 ** 10635 ** The [sqlite3_snapshot_free()] interface is only available when the 10636 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10637 */ 10638 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10639 10640 /* 10641 ** CAPI3REF: Compare the ages of two snapshot handles. 10642 ** METHOD: sqlite3_snapshot 10643 ** 10644 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10645 ** of two valid snapshot handles. 10646 ** 10647 ** If the two snapshot handles are not associated with the same database 10648 ** file, the result of the comparison is undefined. 10649 ** 10650 ** Additionally, the result of the comparison is only valid if both of the 10651 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10652 ** last time the wal file was deleted. The wal file is deleted when the 10653 ** database is changed back to rollback mode or when the number of database 10654 ** clients drops to zero. If either snapshot handle was obtained before the 10655 ** wal file was last deleted, the value returned by this function 10656 ** is undefined. 10657 ** 10658 ** Otherwise, this API returns a negative value if P1 refers to an older 10659 ** snapshot than P2, zero if the two handles refer to the same database 10660 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10661 ** 10662 ** This interface is only available if SQLite is compiled with the 10663 ** [SQLITE_ENABLE_SNAPSHOT] option. 10664 */ 10665 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10666 sqlite3_snapshot *p1, 10667 sqlite3_snapshot *p2 10668 ); 10669 10670 /* 10671 ** CAPI3REF: Recover snapshots from a wal file 10672 ** METHOD: sqlite3_snapshot 10673 ** 10674 ** If a [WAL file] remains on disk after all database connections close 10675 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10676 ** or because the last process to have the database opened exited without 10677 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10678 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10679 ** will only be able to open the last transaction added to the WAL file 10680 ** even though the WAL file contains other valid transactions. 10681 ** 10682 ** This function attempts to scan the WAL file associated with database zDb 10683 ** of database handle db and make all valid snapshots available to 10684 ** sqlite3_snapshot_open(). It is an error if there is already a read 10685 ** transaction open on the database, or if the database is not a WAL mode 10686 ** database. 10687 ** 10688 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10689 ** 10690 ** This interface is only available if SQLite is compiled with the 10691 ** [SQLITE_ENABLE_SNAPSHOT] option. 10692 */ 10693 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10694 10695 /* 10696 ** CAPI3REF: Serialize a database 10697 ** 10698 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10699 ** that is a serialization of the S database on [database connection] D. 10700 ** If P is not a NULL pointer, then the size of the database in bytes 10701 ** is written into *P. 10702 ** 10703 ** For an ordinary on-disk database file, the serialization is just a 10704 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10705 ** the serialization is the same sequence of bytes which would be written 10706 ** to disk if that database where backed up to disk. 10707 ** 10708 ** The usual case is that sqlite3_serialize() copies the serialization of 10709 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10710 ** a pointer to that memory. The caller is responsible for freeing the 10711 ** returned value to avoid a memory leak. However, if the F argument 10712 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10713 ** are made, and the sqlite3_serialize() function will return a pointer 10714 ** to the contiguous memory representation of the database that SQLite 10715 ** is currently using for that database, or NULL if the no such contiguous 10716 ** memory representation of the database exists. A contiguous memory 10717 ** representation of the database will usually only exist if there has 10718 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10719 ** values of D and S. 10720 ** The size of the database is written into *P even if the 10721 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10722 ** of the database exists. 10723 ** 10724 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set, 10725 ** the returned buffer content will remain accessible and unchanged 10726 ** until either the next write operation on the connection or when 10727 ** the connection is closed, and applications must not modify the 10728 ** buffer. If the bit had been clear, the returned buffer will not 10729 ** be accessed by SQLite after the call. 10730 ** 10731 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10732 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10733 ** allocation error occurs. 10734 ** 10735 ** This interface is omitted if SQLite is compiled with the 10736 ** [SQLITE_OMIT_DESERIALIZE] option. 10737 */ 10738 SQLITE_API unsigned char *sqlite3_serialize( 10739 sqlite3 *db, /* The database connection */ 10740 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10741 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10742 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10743 ); 10744 10745 /* 10746 ** CAPI3REF: Flags for sqlite3_serialize 10747 ** 10748 ** Zero or more of the following constants can be OR-ed together for 10749 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10750 ** 10751 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10752 ** a pointer to contiguous in-memory database that it is currently using, 10753 ** without making a copy of the database. If SQLite is not currently using 10754 ** a contiguous in-memory database, then this option causes 10755 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10756 ** using a contiguous in-memory database if it has been initialized by a 10757 ** prior call to [sqlite3_deserialize()]. 10758 */ 10759 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10760 10761 /* 10762 ** CAPI3REF: Deserialize a database 10763 ** 10764 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10765 ** [database connection] D to disconnect from database S and then 10766 ** reopen S as an in-memory database based on the serialization contained 10767 ** in P. The serialized database P is N bytes in size. M is the size of 10768 ** the buffer P, which might be larger than N. If M is larger than N, and 10769 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10770 ** permitted to add content to the in-memory database as long as the total 10771 ** size does not exceed M bytes. 10772 ** 10773 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10774 ** invoke sqlite3_free() on the serialization buffer when the database 10775 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10776 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10777 ** if writes on the database cause it to grow larger than M bytes. 10778 ** 10779 ** Applications must not modify the buffer P or invalidate it before 10780 ** the database connection D is closed. 10781 ** 10782 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10783 ** database is currently in a read transaction or is involved in a backup 10784 ** operation. 10785 ** 10786 ** It is not possible to deserialized into the TEMP database. If the 10787 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10788 ** function returns SQLITE_ERROR. 10789 ** 10790 ** The deserialized database should not be in [WAL mode]. If the database 10791 ** is in WAL mode, then any attempt to use the database file will result 10792 ** in an [SQLITE_CANTOPEN] error. The application can set the 10793 ** [file format version numbers] (bytes 18 and 19) of the input database P 10794 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the 10795 ** database file into rollback mode and work around this limitation. 10796 ** 10797 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10798 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10799 ** [sqlite3_free()] is invoked on argument P prior to returning. 10800 ** 10801 ** This interface is omitted if SQLite is compiled with the 10802 ** [SQLITE_OMIT_DESERIALIZE] option. 10803 */ 10804 SQLITE_API int sqlite3_deserialize( 10805 sqlite3 *db, /* The database connection */ 10806 const char *zSchema, /* Which DB to reopen with the deserialization */ 10807 unsigned char *pData, /* The serialized database content */ 10808 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10809 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10810 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10811 ); 10812 10813 /* 10814 ** CAPI3REF: Flags for sqlite3_deserialize() 10815 ** 10816 ** The following are allowed values for 6th argument (the F argument) to 10817 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10818 ** 10819 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10820 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10821 ** and that SQLite should take ownership of this memory and automatically 10822 ** free it when it has finished using it. Without this flag, the caller 10823 ** is responsible for freeing any dynamically allocated memory. 10824 ** 10825 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10826 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10827 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10828 ** Without this flag, the deserialized database cannot increase in size beyond 10829 ** the number of bytes specified by the M parameter. 10830 ** 10831 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10832 ** should be treated as read-only. 10833 */ 10834 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10835 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10836 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10837 10838 /* 10839 ** Undo the hack that converts floating point types to integer for 10840 ** builds on processors without floating point support. 10841 */ 10842 #ifdef SQLITE_OMIT_FLOATING_POINT 10843 # undef double 10844 #endif 10845 10846 #if defined(__wasi__) 10847 # undef SQLITE_WASI 10848 # define SQLITE_WASI 1 10849 # undef SQLITE_OMIT_WAL 10850 # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */ 10851 # ifndef SQLITE_OMIT_LOAD_EXTENSION 10852 # define SQLITE_OMIT_LOAD_EXTENSION 10853 # endif 10854 # ifndef SQLITE_THREADSAFE 10855 # define SQLITE_THREADSAFE 0 10856 # endif 10857 #endif 10858 10859 #ifdef __cplusplus 10860 } /* End of the 'extern "C"' block */ 10861 #endif 10862 #endif /* SQLITE3_H */ 10863 10864 /******** Begin file sqlite3rtree.h *********/ 10865 /* 10866 ** 2010 August 30 10867 ** 10868 ** The author disclaims copyright to this source code. In place of 10869 ** a legal notice, here is a blessing: 10870 ** 10871 ** May you do good and not evil. 10872 ** May you find forgiveness for yourself and forgive others. 10873 ** May you share freely, never taking more than you give. 10874 ** 10875 ************************************************************************* 10876 */ 10877 10878 #ifndef _SQLITE3RTREE_H_ 10879 #define _SQLITE3RTREE_H_ 10880 10881 10882 #ifdef __cplusplus 10883 extern "C" { 10884 #endif 10885 10886 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10887 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10888 10889 /* The double-precision datatype used by RTree depends on the 10890 ** SQLITE_RTREE_INT_ONLY compile-time option. 10891 */ 10892 #ifdef SQLITE_RTREE_INT_ONLY 10893 typedef sqlite3_int64 sqlite3_rtree_dbl; 10894 #else 10895 typedef double sqlite3_rtree_dbl; 10896 #endif 10897 10898 /* 10899 ** Register a geometry callback named zGeom that can be used as part of an 10900 ** R-Tree geometry query as follows: 10901 ** 10902 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10903 */ 10904 SQLITE_API int sqlite3_rtree_geometry_callback( 10905 sqlite3 *db, 10906 const char *zGeom, 10907 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10908 void *pContext 10909 ); 10910 10911 10912 /* 10913 ** A pointer to a structure of the following type is passed as the first 10914 ** argument to callbacks registered using rtree_geometry_callback(). 10915 */ 10916 struct sqlite3_rtree_geometry { 10917 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10918 int nParam; /* Size of array aParam[] */ 10919 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10920 void *pUser; /* Callback implementation user data */ 10921 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10922 }; 10923 10924 /* 10925 ** Register a 2nd-generation geometry callback named zScore that can be 10926 ** used as part of an R-Tree geometry query as follows: 10927 ** 10928 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10929 */ 10930 SQLITE_API int sqlite3_rtree_query_callback( 10931 sqlite3 *db, 10932 const char *zQueryFunc, 10933 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10934 void *pContext, 10935 void (*xDestructor)(void*) 10936 ); 10937 10938 10939 /* 10940 ** A pointer to a structure of the following type is passed as the 10941 ** argument to scored geometry callback registered using 10942 ** sqlite3_rtree_query_callback(). 10943 ** 10944 ** Note that the first 5 fields of this structure are identical to 10945 ** sqlite3_rtree_geometry. This structure is a subclass of 10946 ** sqlite3_rtree_geometry. 10947 */ 10948 struct sqlite3_rtree_query_info { 10949 void *pContext; /* pContext from when function registered */ 10950 int nParam; /* Number of function parameters */ 10951 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10952 void *pUser; /* callback can use this, if desired */ 10953 void (*xDelUser)(void*); /* function to free pUser */ 10954 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10955 unsigned int *anQueue; /* Number of pending entries in the queue */ 10956 int nCoord; /* Number of coordinates */ 10957 int iLevel; /* Level of current node or entry */ 10958 int mxLevel; /* The largest iLevel value in the tree */ 10959 sqlite3_int64 iRowid; /* Rowid for current entry */ 10960 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10961 int eParentWithin; /* Visibility of parent node */ 10962 int eWithin; /* OUT: Visibility */ 10963 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10964 /* The following fields are only available in 3.8.11 and later */ 10965 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10966 }; 10967 10968 /* 10969 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10970 */ 10971 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10972 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10973 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10974 10975 10976 #ifdef __cplusplus 10977 } /* end of the 'extern "C"' block */ 10978 #endif 10979 10980 #endif /* ifndef _SQLITE3RTREE_H_ */ 10981 10982 /******** End of sqlite3rtree.h *********/ 10983 /******** Begin file sqlite3session.h *********/ 10984 10985 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10986 #define __SQLITESESSION_H_ 1 10987 10988 /* 10989 ** Make sure we can call this stuff from C++. 10990 */ 10991 #ifdef __cplusplus 10992 extern "C" { 10993 #endif 10994 10995 10996 /* 10997 ** CAPI3REF: Session Object Handle 10998 ** 10999 ** An instance of this object is a [session] that can be used to 11000 ** record changes to a database. 11001 */ 11002 typedef struct sqlite3_session sqlite3_session; 11003 11004 /* 11005 ** CAPI3REF: Changeset Iterator Handle 11006 ** 11007 ** An instance of this object acts as a cursor for iterating 11008 ** over the elements of a [changeset] or [patchset]. 11009 */ 11010 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 11011 11012 /* 11013 ** CAPI3REF: Create A New Session Object 11014 ** CONSTRUCTOR: sqlite3_session 11015 ** 11016 ** Create a new session object attached to database handle db. If successful, 11017 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 11018 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 11019 ** error code (e.g. SQLITE_NOMEM) is returned. 11020 ** 11021 ** It is possible to create multiple session objects attached to a single 11022 ** database handle. 11023 ** 11024 ** Session objects created using this function should be deleted using the 11025 ** [sqlite3session_delete()] function before the database handle that they 11026 ** are attached to is itself closed. If the database handle is closed before 11027 ** the session object is deleted, then the results of calling any session 11028 ** module function, including [sqlite3session_delete()] on the session object 11029 ** are undefined. 11030 ** 11031 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 11032 ** is not possible for an application to register a pre-update hook on a 11033 ** database handle that has one or more session objects attached. Nor is 11034 ** it possible to create a session object attached to a database handle for 11035 ** which a pre-update hook is already defined. The results of attempting 11036 ** either of these things are undefined. 11037 ** 11038 ** The session object will be used to create changesets for tables in 11039 ** database zDb, where zDb is either "main", or "temp", or the name of an 11040 ** attached database. It is not an error if database zDb is not attached 11041 ** to the database when the session object is created. 11042 */ 11043 SQLITE_API int sqlite3session_create( 11044 sqlite3 *db, /* Database handle */ 11045 const char *zDb, /* Name of db (e.g. "main") */ 11046 sqlite3_session **ppSession /* OUT: New session object */ 11047 ); 11048 11049 /* 11050 ** CAPI3REF: Delete A Session Object 11051 ** DESTRUCTOR: sqlite3_session 11052 ** 11053 ** Delete a session object previously allocated using 11054 ** [sqlite3session_create()]. Once a session object has been deleted, the 11055 ** results of attempting to use pSession with any other session module 11056 ** function are undefined. 11057 ** 11058 ** Session objects must be deleted before the database handle to which they 11059 ** are attached is closed. Refer to the documentation for 11060 ** [sqlite3session_create()] for details. 11061 */ 11062 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 11063 11064 /* 11065 ** CAPI3REF: Configure a Session Object 11066 ** METHOD: sqlite3_session 11067 ** 11068 ** This method is used to configure a session object after it has been 11069 ** created. At present the only valid values for the second parameter are 11070 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID]. 11071 ** 11072 */ 11073 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 11074 11075 /* 11076 ** CAPI3REF: Options for sqlite3session_object_config 11077 ** 11078 ** The following values may passed as the the 2nd parameter to 11079 ** sqlite3session_object_config(). 11080 ** 11081 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 11082 ** This option is used to set, clear or query the flag that enables 11083 ** the [sqlite3session_changeset_size()] API. Because it imposes some 11084 ** computational overhead, this API is disabled by default. Argument 11085 ** pArg must point to a value of type (int). If the value is initially 11086 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 11087 ** is greater than 0, then the same API is enabled. Or, if the initial 11088 ** value is less than zero, no change is made. In all cases the (int) 11089 ** variable is set to 1 if the sqlite3session_changeset_size() API is 11090 ** enabled following the current call, or 0 otherwise. 11091 ** 11092 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11093 ** the first table has been attached to the session object. 11094 ** 11095 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd> 11096 ** This option is used to set, clear or query the flag that enables 11097 ** collection of data for tables with no explicit PRIMARY KEY. 11098 ** 11099 ** Normally, tables with no explicit PRIMARY KEY are simply ignored 11100 ** by the sessions module. However, if this flag is set, it behaves 11101 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted 11102 ** as their leftmost columns. 11103 ** 11104 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 11105 ** the first table has been attached to the session object. 11106 */ 11107 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 11108 #define SQLITE_SESSION_OBJCONFIG_ROWID 2 11109 11110 /* 11111 ** CAPI3REF: Enable Or Disable A Session Object 11112 ** METHOD: sqlite3_session 11113 ** 11114 ** Enable or disable the recording of changes by a session object. When 11115 ** enabled, a session object records changes made to the database. When 11116 ** disabled - it does not. A newly created session object is enabled. 11117 ** Refer to the documentation for [sqlite3session_changeset()] for further 11118 ** details regarding how enabling and disabling a session object affects 11119 ** the eventual changesets. 11120 ** 11121 ** Passing zero to this function disables the session. Passing a value 11122 ** greater than zero enables it. Passing a value less than zero is a 11123 ** no-op, and may be used to query the current state of the session. 11124 ** 11125 ** The return value indicates the final state of the session object: 0 if 11126 ** the session is disabled, or 1 if it is enabled. 11127 */ 11128 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 11129 11130 /* 11131 ** CAPI3REF: Set Or Clear the Indirect Change Flag 11132 ** METHOD: sqlite3_session 11133 ** 11134 ** Each change recorded by a session object is marked as either direct or 11135 ** indirect. A change is marked as indirect if either: 11136 ** 11137 ** <ul> 11138 ** <li> The session object "indirect" flag is set when the change is 11139 ** made, or 11140 ** <li> The change is made by an SQL trigger or foreign key action 11141 ** instead of directly as a result of a users SQL statement. 11142 ** </ul> 11143 ** 11144 ** If a single row is affected by more than one operation within a session, 11145 ** then the change is considered indirect if all operations meet the criteria 11146 ** for an indirect change above, or direct otherwise. 11147 ** 11148 ** This function is used to set, clear or query the session object indirect 11149 ** flag. If the second argument passed to this function is zero, then the 11150 ** indirect flag is cleared. If it is greater than zero, the indirect flag 11151 ** is set. Passing a value less than zero does not modify the current value 11152 ** of the indirect flag, and may be used to query the current state of the 11153 ** indirect flag for the specified session object. 11154 ** 11155 ** The return value indicates the final state of the indirect flag: 0 if 11156 ** it is clear, or 1 if it is set. 11157 */ 11158 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 11159 11160 /* 11161 ** CAPI3REF: Attach A Table To A Session Object 11162 ** METHOD: sqlite3_session 11163 ** 11164 ** If argument zTab is not NULL, then it is the name of a table to attach 11165 ** to the session object passed as the first argument. All subsequent changes 11166 ** made to the table while the session object is enabled will be recorded. See 11167 ** documentation for [sqlite3session_changeset()] for further details. 11168 ** 11169 ** Or, if argument zTab is NULL, then changes are recorded for all tables 11170 ** in the database. If additional tables are added to the database (by 11171 ** executing "CREATE TABLE" statements) after this call is made, changes for 11172 ** the new tables are also recorded. 11173 ** 11174 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 11175 ** defined as part of their CREATE TABLE statement. It does not matter if the 11176 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 11177 ** KEY may consist of a single column, or may be a composite key. 11178 ** 11179 ** It is not an error if the named table does not exist in the database. Nor 11180 ** is it an error if the named table does not have a PRIMARY KEY. However, 11181 ** no changes will be recorded in either of these scenarios. 11182 ** 11183 ** Changes are not recorded for individual rows that have NULL values stored 11184 ** in one or more of their PRIMARY KEY columns. 11185 ** 11186 ** SQLITE_OK is returned if the call completes without error. Or, if an error 11187 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 11188 ** 11189 ** <h3>Special sqlite_stat1 Handling</h3> 11190 ** 11191 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 11192 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 11193 ** <pre> 11194 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 11195 ** </pre> 11196 ** 11197 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 11198 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 11199 ** are recorded for rows for which (idx IS NULL) is true. However, for such 11200 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 11201 ** patchset instead of a NULL value. This allows such changesets to be 11202 ** manipulated by legacy implementations of sqlite3changeset_invert(), 11203 ** concat() and similar. 11204 ** 11205 ** The sqlite3changeset_apply() function automatically converts the 11206 ** zero-length blob back to a NULL value when updating the sqlite_stat1 11207 ** table. However, if the application calls sqlite3changeset_new(), 11208 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 11209 ** iterator directly (including on a changeset iterator passed to a 11210 ** conflict-handler callback) then the X'' value is returned. The application 11211 ** must translate X'' to NULL itself if required. 11212 ** 11213 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 11214 ** changes made to the sqlite_stat1 table. Legacy versions of the 11215 ** sqlite3changeset_apply() function silently ignore any modifications to the 11216 ** sqlite_stat1 table that are part of a changeset or patchset. 11217 */ 11218 SQLITE_API int sqlite3session_attach( 11219 sqlite3_session *pSession, /* Session object */ 11220 const char *zTab /* Table name */ 11221 ); 11222 11223 /* 11224 ** CAPI3REF: Set a table filter on a Session Object. 11225 ** METHOD: sqlite3_session 11226 ** 11227 ** The second argument (xFilter) is the "filter callback". For changes to rows 11228 ** in tables that are not attached to the Session object, the filter is called 11229 ** to determine whether changes to the table's rows should be tracked or not. 11230 ** If xFilter returns 0, changes are not tracked. Note that once a table is 11231 ** attached, xFilter will not be called again. 11232 */ 11233 SQLITE_API void sqlite3session_table_filter( 11234 sqlite3_session *pSession, /* Session object */ 11235 int(*xFilter)( 11236 void *pCtx, /* Copy of third arg to _filter_table() */ 11237 const char *zTab /* Table name */ 11238 ), 11239 void *pCtx /* First argument passed to xFilter */ 11240 ); 11241 11242 /* 11243 ** CAPI3REF: Generate A Changeset From A Session Object 11244 ** METHOD: sqlite3_session 11245 ** 11246 ** Obtain a changeset containing changes to the tables attached to the 11247 ** session object passed as the first argument. If successful, 11248 ** set *ppChangeset to point to a buffer containing the changeset 11249 ** and *pnChangeset to the size of the changeset in bytes before returning 11250 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 11251 ** zero and return an SQLite error code. 11252 ** 11253 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 11254 ** each representing a change to a single row of an attached table. An INSERT 11255 ** change contains the values of each field of a new database row. A DELETE 11256 ** contains the original values of each field of a deleted database row. An 11257 ** UPDATE change contains the original values of each field of an updated 11258 ** database row along with the updated values for each updated non-primary-key 11259 ** column. It is not possible for an UPDATE change to represent a change that 11260 ** modifies the values of primary key columns. If such a change is made, it 11261 ** is represented in a changeset as a DELETE followed by an INSERT. 11262 ** 11263 ** Changes are not recorded for rows that have NULL values stored in one or 11264 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 11265 ** no corresponding change is present in the changesets returned by this 11266 ** function. If an existing row with one or more NULL values stored in 11267 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 11268 ** only an INSERT is appears in the changeset. Similarly, if an existing row 11269 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 11270 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 11271 ** DELETE change only. 11272 ** 11273 ** The contents of a changeset may be traversed using an iterator created 11274 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 11275 ** a database with a compatible schema using the [sqlite3changeset_apply()] 11276 ** API. 11277 ** 11278 ** Within a changeset generated by this function, all changes related to a 11279 ** single table are grouped together. In other words, when iterating through 11280 ** a changeset or when applying a changeset to a database, all changes related 11281 ** to a single table are processed before moving on to the next table. Tables 11282 ** are sorted in the same order in which they were attached (or auto-attached) 11283 ** to the sqlite3_session object. The order in which the changes related to 11284 ** a single table are stored is undefined. 11285 ** 11286 ** Following a successful call to this function, it is the responsibility of 11287 ** the caller to eventually free the buffer that *ppChangeset points to using 11288 ** [sqlite3_free()]. 11289 ** 11290 ** <h3>Changeset Generation</h3> 11291 ** 11292 ** Once a table has been attached to a session object, the session object 11293 ** records the primary key values of all new rows inserted into the table. 11294 ** It also records the original primary key and other column values of any 11295 ** deleted or updated rows. For each unique primary key value, data is only 11296 ** recorded once - the first time a row with said primary key is inserted, 11297 ** updated or deleted in the lifetime of the session. 11298 ** 11299 ** There is one exception to the previous paragraph: when a row is inserted, 11300 ** updated or deleted, if one or more of its primary key columns contain a 11301 ** NULL value, no record of the change is made. 11302 ** 11303 ** The session object therefore accumulates two types of records - those 11304 ** that consist of primary key values only (created when the user inserts 11305 ** a new record) and those that consist of the primary key values and the 11306 ** original values of other table columns (created when the users deletes 11307 ** or updates a record). 11308 ** 11309 ** When this function is called, the requested changeset is created using 11310 ** both the accumulated records and the current contents of the database 11311 ** file. Specifically: 11312 ** 11313 ** <ul> 11314 ** <li> For each record generated by an insert, the database is queried 11315 ** for a row with a matching primary key. If one is found, an INSERT 11316 ** change is added to the changeset. If no such row is found, no change 11317 ** is added to the changeset. 11318 ** 11319 ** <li> For each record generated by an update or delete, the database is 11320 ** queried for a row with a matching primary key. If such a row is 11321 ** found and one or more of the non-primary key fields have been 11322 ** modified from their original values, an UPDATE change is added to 11323 ** the changeset. Or, if no such row is found in the table, a DELETE 11324 ** change is added to the changeset. If there is a row with a matching 11325 ** primary key in the database, but all fields contain their original 11326 ** values, no change is added to the changeset. 11327 ** </ul> 11328 ** 11329 ** This means, amongst other things, that if a row is inserted and then later 11330 ** deleted while a session object is active, neither the insert nor the delete 11331 ** will be present in the changeset. Or if a row is deleted and then later a 11332 ** row with the same primary key values inserted while a session object is 11333 ** active, the resulting changeset will contain an UPDATE change instead of 11334 ** a DELETE and an INSERT. 11335 ** 11336 ** When a session object is disabled (see the [sqlite3session_enable()] API), 11337 ** it does not accumulate records when rows are inserted, updated or deleted. 11338 ** This may appear to have some counter-intuitive effects if a single row 11339 ** is written to more than once during a session. For example, if a row 11340 ** is inserted while a session object is enabled, then later deleted while 11341 ** the same session object is disabled, no INSERT record will appear in the 11342 ** changeset, even though the delete took place while the session was disabled. 11343 ** Or, if one field of a row is updated while a session is disabled, and 11344 ** another field of the same row is updated while the session is enabled, the 11345 ** resulting changeset will contain an UPDATE change that updates both fields. 11346 */ 11347 SQLITE_API int sqlite3session_changeset( 11348 sqlite3_session *pSession, /* Session object */ 11349 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11350 void **ppChangeset /* OUT: Buffer containing changeset */ 11351 ); 11352 11353 /* 11354 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11355 ** METHOD: sqlite3_session 11356 ** 11357 ** By default, this function always returns 0. For it to return 11358 ** a useful result, the sqlite3_session object must have been configured 11359 ** to enable this API using sqlite3session_object_config() with the 11360 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11361 ** 11362 ** When enabled, this function returns an upper limit, in bytes, for the size 11363 ** of the changeset that might be produced if sqlite3session_changeset() were 11364 ** called. The final changeset size might be equal to or smaller than the 11365 ** size in bytes returned by this function. 11366 */ 11367 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11368 11369 /* 11370 ** CAPI3REF: Load The Difference Between Tables Into A Session 11371 ** METHOD: sqlite3_session 11372 ** 11373 ** If it is not already attached to the session object passed as the first 11374 ** argument, this function attaches table zTbl in the same manner as the 11375 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11376 ** does not have a primary key, this function is a no-op (but does not return 11377 ** an error). 11378 ** 11379 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11380 ** attached to the same database handle as the session object that contains 11381 ** a table compatible with the table attached to the session by this function. 11382 ** A table is considered compatible if it: 11383 ** 11384 ** <ul> 11385 ** <li> Has the same name, 11386 ** <li> Has the same set of columns declared in the same order, and 11387 ** <li> Has the same PRIMARY KEY definition. 11388 ** </ul> 11389 ** 11390 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11391 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11392 ** but no changes are added to the session object. As with other session 11393 ** APIs, tables without PRIMARY KEYs are simply ignored. 11394 ** 11395 ** This function adds a set of changes to the session object that could be 11396 ** used to update the table in database zFrom (call this the "from-table") 11397 ** so that its content is the same as the table attached to the session 11398 ** object (call this the "to-table"). Specifically: 11399 ** 11400 ** <ul> 11401 ** <li> For each row (primary key) that exists in the to-table but not in 11402 ** the from-table, an INSERT record is added to the session object. 11403 ** 11404 ** <li> For each row (primary key) that exists in the to-table but not in 11405 ** the from-table, a DELETE record is added to the session object. 11406 ** 11407 ** <li> For each row (primary key) that exists in both tables, but features 11408 ** different non-PK values in each, an UPDATE record is added to the 11409 ** session. 11410 ** </ul> 11411 ** 11412 ** To clarify, if this function is called and then a changeset constructed 11413 ** using [sqlite3session_changeset()], then after applying that changeset to 11414 ** database zFrom the contents of the two compatible tables would be 11415 ** identical. 11416 ** 11417 ** It an error if database zFrom does not exist or does not contain the 11418 ** required compatible table. 11419 ** 11420 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11421 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11422 ** may be set to point to a buffer containing an English language error 11423 ** message. It is the responsibility of the caller to free this buffer using 11424 ** sqlite3_free(). 11425 */ 11426 SQLITE_API int sqlite3session_diff( 11427 sqlite3_session *pSession, 11428 const char *zFromDb, 11429 const char *zTbl, 11430 char **pzErrMsg 11431 ); 11432 11433 11434 /* 11435 ** CAPI3REF: Generate A Patchset From A Session Object 11436 ** METHOD: sqlite3_session 11437 ** 11438 ** The differences between a patchset and a changeset are that: 11439 ** 11440 ** <ul> 11441 ** <li> DELETE records consist of the primary key fields only. The 11442 ** original values of other fields are omitted. 11443 ** <li> The original values of any modified fields are omitted from 11444 ** UPDATE records. 11445 ** </ul> 11446 ** 11447 ** A patchset blob may be used with up to date versions of all 11448 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11449 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11450 ** attempting to use a patchset blob with old versions of the 11451 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11452 ** 11453 ** Because the non-primary key "old.*" fields are omitted, no 11454 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11455 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11456 ** in the same way as for changesets. 11457 ** 11458 ** Changes within a patchset are ordered in the same way as for changesets 11459 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11460 ** a single table are grouped together, tables appear in the order in which 11461 ** they were attached to the session object). 11462 */ 11463 SQLITE_API int sqlite3session_patchset( 11464 sqlite3_session *pSession, /* Session object */ 11465 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11466 void **ppPatchset /* OUT: Buffer containing patchset */ 11467 ); 11468 11469 /* 11470 ** CAPI3REF: Test if a changeset has recorded any changes. 11471 ** 11472 ** Return non-zero if no changes to attached tables have been recorded by 11473 ** the session object passed as the first argument. Otherwise, if one or 11474 ** more changes have been recorded, return zero. 11475 ** 11476 ** Even if this function returns zero, it is possible that calling 11477 ** [sqlite3session_changeset()] on the session handle may still return a 11478 ** changeset that contains no changes. This can happen when a row in 11479 ** an attached table is modified and then later on the original values 11480 ** are restored. However, if this function returns non-zero, then it is 11481 ** guaranteed that a call to sqlite3session_changeset() will return a 11482 ** changeset containing zero changes. 11483 */ 11484 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11485 11486 /* 11487 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11488 ** 11489 ** This API returns the total amount of heap memory in bytes currently 11490 ** used by the session object passed as the only argument. 11491 */ 11492 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11493 11494 /* 11495 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11496 ** CONSTRUCTOR: sqlite3_changeset_iter 11497 ** 11498 ** Create an iterator used to iterate through the contents of a changeset. 11499 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11500 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11501 ** SQLite error code is returned. 11502 ** 11503 ** The following functions can be used to advance and query a changeset 11504 ** iterator created by this function: 11505 ** 11506 ** <ul> 11507 ** <li> [sqlite3changeset_next()] 11508 ** <li> [sqlite3changeset_op()] 11509 ** <li> [sqlite3changeset_new()] 11510 ** <li> [sqlite3changeset_old()] 11511 ** </ul> 11512 ** 11513 ** It is the responsibility of the caller to eventually destroy the iterator 11514 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11515 ** changeset (pChangeset) must remain valid until after the iterator is 11516 ** destroyed. 11517 ** 11518 ** Assuming the changeset blob was created by one of the 11519 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11520 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11521 ** that apply to a single table are grouped together. This means that when 11522 ** an application iterates through a changeset using an iterator created by 11523 ** this function, all changes that relate to a single table are visited 11524 ** consecutively. There is no chance that the iterator will visit a change 11525 ** the applies to table X, then one for table Y, and then later on visit 11526 ** another change for table X. 11527 ** 11528 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11529 ** may be modified by passing a combination of 11530 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11531 ** 11532 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11533 ** and therefore subject to change. 11534 */ 11535 SQLITE_API int sqlite3changeset_start( 11536 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11537 int nChangeset, /* Size of changeset blob in bytes */ 11538 void *pChangeset /* Pointer to blob containing changeset */ 11539 ); 11540 SQLITE_API int sqlite3changeset_start_v2( 11541 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11542 int nChangeset, /* Size of changeset blob in bytes */ 11543 void *pChangeset, /* Pointer to blob containing changeset */ 11544 int flags /* SESSION_CHANGESETSTART_* flags */ 11545 ); 11546 11547 /* 11548 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11549 ** 11550 ** The following flags may passed via the 4th parameter to 11551 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11552 ** 11553 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11554 ** Invert the changeset while iterating through it. This is equivalent to 11555 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11556 ** It is an error to specify this flag with a patchset. 11557 */ 11558 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11559 11560 11561 /* 11562 ** CAPI3REF: Advance A Changeset Iterator 11563 ** METHOD: sqlite3_changeset_iter 11564 ** 11565 ** This function may only be used with iterators created by the function 11566 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11567 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11568 ** is returned and the call has no effect. 11569 ** 11570 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11571 ** does not point to any change in the changeset. Assuming the changeset 11572 ** is not empty, the first call to this function advances the iterator to 11573 ** point to the first change in the changeset. Each subsequent call advances 11574 ** the iterator to point to the next change in the changeset (if any). If 11575 ** no error occurs and the iterator points to a valid change after a call 11576 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11577 ** Otherwise, if all changes in the changeset have already been visited, 11578 ** SQLITE_DONE is returned. 11579 ** 11580 ** If an error occurs, an SQLite error code is returned. Possible error 11581 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11582 ** SQLITE_NOMEM. 11583 */ 11584 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11585 11586 /* 11587 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11588 ** METHOD: sqlite3_changeset_iter 11589 ** 11590 ** The pIter argument passed to this function may either be an iterator 11591 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11592 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11593 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11594 ** is not the case, this function returns [SQLITE_MISUSE]. 11595 ** 11596 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11597 ** outputs are set through these pointers: 11598 ** 11599 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11600 ** depending on the type of change that the iterator currently points to; 11601 ** 11602 ** *pnCol is set to the number of columns in the table affected by the change; and 11603 ** 11604 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11605 ** the name of the table affected by the current change. The buffer remains 11606 ** valid until either sqlite3changeset_next() is called on the iterator 11607 ** or until the conflict-handler function returns. 11608 ** 11609 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11610 ** is an indirect change, or false (0) otherwise. See the documentation for 11611 ** [sqlite3session_indirect()] for a description of direct and indirect 11612 ** changes. 11613 ** 11614 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11615 ** SQLite error code is returned. The values of the output variables may not 11616 ** be trusted in this case. 11617 */ 11618 SQLITE_API int sqlite3changeset_op( 11619 sqlite3_changeset_iter *pIter, /* Iterator object */ 11620 const char **pzTab, /* OUT: Pointer to table name */ 11621 int *pnCol, /* OUT: Number of columns in table */ 11622 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11623 int *pbIndirect /* OUT: True for an 'indirect' change */ 11624 ); 11625 11626 /* 11627 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11628 ** METHOD: sqlite3_changeset_iter 11629 ** 11630 ** For each modified table, a changeset includes the following: 11631 ** 11632 ** <ul> 11633 ** <li> The number of columns in the table, and 11634 ** <li> Which of those columns make up the tables PRIMARY KEY. 11635 ** </ul> 11636 ** 11637 ** This function is used to find which columns comprise the PRIMARY KEY of 11638 ** the table modified by the change that iterator pIter currently points to. 11639 ** If successful, *pabPK is set to point to an array of nCol entries, where 11640 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11641 ** 0x01 if the corresponding column is part of the tables primary key, or 11642 ** 0x00 if it is not. 11643 ** 11644 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11645 ** in the table. 11646 ** 11647 ** If this function is called when the iterator does not point to a valid 11648 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11649 ** SQLITE_OK is returned and the output variables populated as described 11650 ** above. 11651 */ 11652 SQLITE_API int sqlite3changeset_pk( 11653 sqlite3_changeset_iter *pIter, /* Iterator object */ 11654 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11655 int *pnCol /* OUT: Number of entries in output array */ 11656 ); 11657 11658 /* 11659 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11660 ** METHOD: sqlite3_changeset_iter 11661 ** 11662 ** The pIter argument passed to this function may either be an iterator 11663 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11664 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11665 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11666 ** Furthermore, it may only be called if the type of change that the iterator 11667 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11668 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11669 ** 11670 ** Argument iVal must be greater than or equal to 0, and less than the number 11671 ** of columns in the table affected by the current change. Otherwise, 11672 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11673 ** 11674 ** If successful, this function sets *ppValue to point to a protected 11675 ** sqlite3_value object containing the iVal'th value from the vector of 11676 ** original row values stored as part of the UPDATE or DELETE change and 11677 ** returns SQLITE_OK. The name of the function comes from the fact that this 11678 ** is similar to the "old.*" columns available to update or delete triggers. 11679 ** 11680 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11681 ** is returned and *ppValue is set to NULL. 11682 */ 11683 SQLITE_API int sqlite3changeset_old( 11684 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11685 int iVal, /* Column number */ 11686 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11687 ); 11688 11689 /* 11690 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11691 ** METHOD: sqlite3_changeset_iter 11692 ** 11693 ** The pIter argument passed to this function may either be an iterator 11694 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11695 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11696 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11697 ** Furthermore, it may only be called if the type of change that the iterator 11698 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11699 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11700 ** 11701 ** Argument iVal must be greater than or equal to 0, and less than the number 11702 ** of columns in the table affected by the current change. Otherwise, 11703 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11704 ** 11705 ** If successful, this function sets *ppValue to point to a protected 11706 ** sqlite3_value object containing the iVal'th value from the vector of 11707 ** new row values stored as part of the UPDATE or INSERT change and 11708 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11709 ** a new value for the requested column, *ppValue is set to NULL and 11710 ** SQLITE_OK returned. The name of the function comes from the fact that 11711 ** this is similar to the "new.*" columns available to update or delete 11712 ** triggers. 11713 ** 11714 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11715 ** is returned and *ppValue is set to NULL. 11716 */ 11717 SQLITE_API int sqlite3changeset_new( 11718 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11719 int iVal, /* Column number */ 11720 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11721 ); 11722 11723 /* 11724 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11725 ** METHOD: sqlite3_changeset_iter 11726 ** 11727 ** This function should only be used with iterator objects passed to a 11728 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11729 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11730 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11731 ** is set to NULL. 11732 ** 11733 ** Argument iVal must be greater than or equal to 0, and less than the number 11734 ** of columns in the table affected by the current change. Otherwise, 11735 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11736 ** 11737 ** If successful, this function sets *ppValue to point to a protected 11738 ** sqlite3_value object containing the iVal'th value from the 11739 ** "conflicting row" associated with the current conflict-handler callback 11740 ** and returns SQLITE_OK. 11741 ** 11742 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11743 ** is returned and *ppValue is set to NULL. 11744 */ 11745 SQLITE_API int sqlite3changeset_conflict( 11746 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11747 int iVal, /* Column number */ 11748 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11749 ); 11750 11751 /* 11752 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11753 ** METHOD: sqlite3_changeset_iter 11754 ** 11755 ** This function may only be called with an iterator passed to an 11756 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11757 ** it sets the output variable to the total number of known foreign key 11758 ** violations in the destination database and returns SQLITE_OK. 11759 ** 11760 ** In all other cases this function returns SQLITE_MISUSE. 11761 */ 11762 SQLITE_API int sqlite3changeset_fk_conflicts( 11763 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11764 int *pnOut /* OUT: Number of FK violations */ 11765 ); 11766 11767 11768 /* 11769 ** CAPI3REF: Finalize A Changeset Iterator 11770 ** METHOD: sqlite3_changeset_iter 11771 ** 11772 ** This function is used to finalize an iterator allocated with 11773 ** [sqlite3changeset_start()]. 11774 ** 11775 ** This function should only be called on iterators created using the 11776 ** [sqlite3changeset_start()] function. If an application calls this 11777 ** function with an iterator passed to a conflict-handler by 11778 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11779 ** call has no effect. 11780 ** 11781 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11782 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11783 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11784 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11785 ** returned. This is to allow the following pattern (pseudo-code): 11786 ** 11787 ** <pre> 11788 ** sqlite3changeset_start(); 11789 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11790 ** // Do something with change. 11791 ** } 11792 ** rc = sqlite3changeset_finalize(); 11793 ** if( rc!=SQLITE_OK ){ 11794 ** // An error has occurred 11795 ** } 11796 ** </pre> 11797 */ 11798 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11799 11800 /* 11801 ** CAPI3REF: Invert A Changeset 11802 ** 11803 ** This function is used to "invert" a changeset object. Applying an inverted 11804 ** changeset to a database reverses the effects of applying the uninverted 11805 ** changeset. Specifically: 11806 ** 11807 ** <ul> 11808 ** <li> Each DELETE change is changed to an INSERT, and 11809 ** <li> Each INSERT change is changed to a DELETE, and 11810 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11811 ** </ul> 11812 ** 11813 ** This function does not change the order in which changes appear within 11814 ** the changeset. It merely reverses the sense of each individual change. 11815 ** 11816 ** If successful, a pointer to a buffer containing the inverted changeset 11817 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11818 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11819 ** zeroed and an SQLite error code returned. 11820 ** 11821 ** It is the responsibility of the caller to eventually call sqlite3_free() 11822 ** on the *ppOut pointer to free the buffer allocation following a successful 11823 ** call to this function. 11824 ** 11825 ** WARNING/TODO: This function currently assumes that the input is a valid 11826 ** changeset. If it is not, the results are undefined. 11827 */ 11828 SQLITE_API int sqlite3changeset_invert( 11829 int nIn, const void *pIn, /* Input changeset */ 11830 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11831 ); 11832 11833 /* 11834 ** CAPI3REF: Concatenate Two Changeset Objects 11835 ** 11836 ** This function is used to concatenate two changesets, A and B, into a 11837 ** single changeset. The result is a changeset equivalent to applying 11838 ** changeset A followed by changeset B. 11839 ** 11840 ** This function combines the two input changesets using an 11841 ** sqlite3_changegroup object. Calling it produces similar results as the 11842 ** following code fragment: 11843 ** 11844 ** <pre> 11845 ** sqlite3_changegroup *pGrp; 11846 ** rc = sqlite3_changegroup_new(&pGrp); 11847 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11848 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11849 ** if( rc==SQLITE_OK ){ 11850 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11851 ** }else{ 11852 ** *ppOut = 0; 11853 ** *pnOut = 0; 11854 ** } 11855 ** </pre> 11856 ** 11857 ** Refer to the sqlite3_changegroup documentation below for details. 11858 */ 11859 SQLITE_API int sqlite3changeset_concat( 11860 int nA, /* Number of bytes in buffer pA */ 11861 void *pA, /* Pointer to buffer containing changeset A */ 11862 int nB, /* Number of bytes in buffer pB */ 11863 void *pB, /* Pointer to buffer containing changeset B */ 11864 int *pnOut, /* OUT: Number of bytes in output changeset */ 11865 void **ppOut /* OUT: Buffer containing output changeset */ 11866 ); 11867 11868 11869 /* 11870 ** CAPI3REF: Upgrade the Schema of a Changeset/Patchset 11871 */ 11872 SQLITE_API int sqlite3changeset_upgrade( 11873 sqlite3 *db, 11874 const char *zDb, 11875 int nIn, const void *pIn, /* Input changeset */ 11876 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11877 ); 11878 11879 11880 11881 /* 11882 ** CAPI3REF: Changegroup Handle 11883 ** 11884 ** A changegroup is an object used to combine two or more 11885 ** [changesets] or [patchsets] 11886 */ 11887 typedef struct sqlite3_changegroup sqlite3_changegroup; 11888 11889 /* 11890 ** CAPI3REF: Create A New Changegroup Object 11891 ** CONSTRUCTOR: sqlite3_changegroup 11892 ** 11893 ** An sqlite3_changegroup object is used to combine two or more changesets 11894 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11895 ** object may combine changesets or patchsets, but not both. The output is 11896 ** always in the same format as the input. 11897 ** 11898 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11899 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11900 ** should eventually free the returned object using a call to 11901 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11902 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11903 ** 11904 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11905 ** 11906 ** <ul> 11907 ** <li> It is created using a call to sqlite3changegroup_new(). 11908 ** 11909 ** <li> Zero or more changesets (or patchsets) are added to the object 11910 ** by calling sqlite3changegroup_add(). 11911 ** 11912 ** <li> The result of combining all input changesets together is obtained 11913 ** by the application via a call to sqlite3changegroup_output(). 11914 ** 11915 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11916 ** </ul> 11917 ** 11918 ** Any number of calls to add() and output() may be made between the calls to 11919 ** new() and delete(), and in any order. 11920 ** 11921 ** As well as the regular sqlite3changegroup_add() and 11922 ** sqlite3changegroup_output() functions, also available are the streaming 11923 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11924 */ 11925 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11926 11927 /* 11928 ** CAPI3REF: Add a Schema to a Changegroup 11929 ** METHOD: sqlite3_changegroup_schema 11930 ** 11931 ** This method may be used to optionally enforce the rule that the changesets 11932 ** added to the changegroup handle must match the schema of database zDb 11933 ** ("main", "temp", or the name of an attached database). If 11934 ** sqlite3changegroup_add() is called to add a changeset that is not compatible 11935 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup 11936 ** object is left in an undefined state. 11937 ** 11938 ** A changeset schema is considered compatible with the database schema in 11939 ** the same way as for sqlite3changeset_apply(). Specifically, for each 11940 ** table in the changeset, there exists a database table with: 11941 ** 11942 ** <ul> 11943 ** <li> The name identified by the changeset, and 11944 ** <li> at least as many columns as recorded in the changeset, and 11945 ** <li> the primary key columns in the same position as recorded in 11946 ** the changeset. 11947 ** </ul> 11948 ** 11949 ** The output of the changegroup object always has the same schema as the 11950 ** database nominated using this function. In cases where changesets passed 11951 ** to sqlite3changegroup_add() have fewer columns than the corresponding table 11952 ** in the database schema, these are filled in using the default column 11953 ** values from the database schema. This makes it possible to combined 11954 ** changesets that have different numbers of columns for a single table 11955 ** within a changegroup, provided that they are otherwise compatible. 11956 */ 11957 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb); 11958 11959 /* 11960 ** CAPI3REF: Add A Changeset To A Changegroup 11961 ** METHOD: sqlite3_changegroup 11962 ** 11963 ** Add all changes within the changeset (or patchset) in buffer pData (size 11964 ** nData bytes) to the changegroup. 11965 ** 11966 ** If the buffer contains a patchset, then all prior calls to this function 11967 ** on the same changegroup object must also have specified patchsets. Or, if 11968 ** the buffer contains a changeset, so must have the earlier calls to this 11969 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11970 ** to the changegroup. 11971 ** 11972 ** Rows within the changeset and changegroup are identified by the values in 11973 ** their PRIMARY KEY columns. A change in the changeset is considered to 11974 ** apply to the same row as a change already present in the changegroup if 11975 ** the two rows have the same primary key. 11976 ** 11977 ** Changes to rows that do not already appear in the changegroup are 11978 ** simply copied into it. Or, if both the new changeset and the changegroup 11979 ** contain changes that apply to a single row, the final contents of the 11980 ** changegroup depends on the type of each change, as follows: 11981 ** 11982 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11983 ** <tr><th style="white-space:pre">Existing Change </th> 11984 ** <th style="white-space:pre">New Change </th> 11985 ** <th>Output Change 11986 ** <tr><td>INSERT <td>INSERT <td> 11987 ** The new change is ignored. This case does not occur if the new 11988 ** changeset was recorded immediately after the changesets already 11989 ** added to the changegroup. 11990 ** <tr><td>INSERT <td>UPDATE <td> 11991 ** The INSERT change remains in the changegroup. The values in the 11992 ** INSERT change are modified as if the row was inserted by the 11993 ** existing change and then updated according to the new change. 11994 ** <tr><td>INSERT <td>DELETE <td> 11995 ** The existing INSERT is removed from the changegroup. The DELETE is 11996 ** not added. 11997 ** <tr><td>UPDATE <td>INSERT <td> 11998 ** The new change is ignored. This case does not occur if the new 11999 ** changeset was recorded immediately after the changesets already 12000 ** added to the changegroup. 12001 ** <tr><td>UPDATE <td>UPDATE <td> 12002 ** The existing UPDATE remains within the changegroup. It is amended 12003 ** so that the accompanying values are as if the row was updated once 12004 ** by the existing change and then again by the new change. 12005 ** <tr><td>UPDATE <td>DELETE <td> 12006 ** The existing UPDATE is replaced by the new DELETE within the 12007 ** changegroup. 12008 ** <tr><td>DELETE <td>INSERT <td> 12009 ** If one or more of the column values in the row inserted by the 12010 ** new change differ from those in the row deleted by the existing 12011 ** change, the existing DELETE is replaced by an UPDATE within the 12012 ** changegroup. Otherwise, if the inserted row is exactly the same 12013 ** as the deleted row, the existing DELETE is simply discarded. 12014 ** <tr><td>DELETE <td>UPDATE <td> 12015 ** The new change is ignored. This case does not occur if the new 12016 ** changeset was recorded immediately after the changesets already 12017 ** added to the changegroup. 12018 ** <tr><td>DELETE <td>DELETE <td> 12019 ** The new change is ignored. This case does not occur if the new 12020 ** changeset was recorded immediately after the changesets already 12021 ** added to the changegroup. 12022 ** </table> 12023 ** 12024 ** If the new changeset contains changes to a table that is already present 12025 ** in the changegroup, then the number of columns and the position of the 12026 ** primary key columns for the table must be consistent. If this is not the 12027 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup 12028 ** object has been configured with a database schema using the 12029 ** sqlite3changegroup_schema() API, then it is possible to combine changesets 12030 ** with different numbers of columns for a single table, provided that 12031 ** they are otherwise compatible. 12032 ** 12033 ** If the input changeset appears to be corrupt and the corruption is 12034 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition 12035 ** occurs during processing, this function returns SQLITE_NOMEM. 12036 ** 12037 ** In all cases, if an error occurs the state of the final contents of the 12038 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned. 12039 */ 12040 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 12041 12042 /* 12043 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 12044 ** METHOD: sqlite3_changegroup 12045 ** 12046 ** Obtain a buffer containing a changeset (or patchset) representing the 12047 ** current contents of the changegroup. If the inputs to the changegroup 12048 ** were themselves changesets, the output is a changeset. Or, if the 12049 ** inputs were patchsets, the output is also a patchset. 12050 ** 12051 ** As with the output of the sqlite3session_changeset() and 12052 ** sqlite3session_patchset() functions, all changes related to a single 12053 ** table are grouped together in the output of this function. Tables appear 12054 ** in the same order as for the very first changeset added to the changegroup. 12055 ** If the second or subsequent changesets added to the changegroup contain 12056 ** changes for tables that do not appear in the first changeset, they are 12057 ** appended onto the end of the output changeset, again in the order in 12058 ** which they are first encountered. 12059 ** 12060 ** If an error occurs, an SQLite error code is returned and the output 12061 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 12062 ** is returned and the output variables are set to the size of and a 12063 ** pointer to the output buffer, respectively. In this case it is the 12064 ** responsibility of the caller to eventually free the buffer using a 12065 ** call to sqlite3_free(). 12066 */ 12067 SQLITE_API int sqlite3changegroup_output( 12068 sqlite3_changegroup*, 12069 int *pnData, /* OUT: Size of output buffer in bytes */ 12070 void **ppData /* OUT: Pointer to output buffer */ 12071 ); 12072 12073 /* 12074 ** CAPI3REF: Delete A Changegroup Object 12075 ** DESTRUCTOR: sqlite3_changegroup 12076 */ 12077 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 12078 12079 /* 12080 ** CAPI3REF: Apply A Changeset To A Database 12081 ** 12082 ** Apply a changeset or patchset to a database. These functions attempt to 12083 ** update the "main" database attached to handle db with the changes found in 12084 ** the changeset passed via the second and third arguments. 12085 ** 12086 ** The fourth argument (xFilter) passed to these functions is the "filter 12087 ** callback". If it is not NULL, then for each table affected by at least one 12088 ** change in the changeset, the filter callback is invoked with 12089 ** the table name as the second argument, and a copy of the context pointer 12090 ** passed as the sixth argument as the first. If the "filter callback" 12091 ** returns zero, then no attempt is made to apply any changes to the table. 12092 ** Otherwise, if the return value is non-zero or the xFilter argument to 12093 ** is NULL, all changes related to the table are attempted. 12094 ** 12095 ** For each table that is not excluded by the filter callback, this function 12096 ** tests that the target database contains a compatible table. A table is 12097 ** considered compatible if all of the following are true: 12098 ** 12099 ** <ul> 12100 ** <li> The table has the same name as the name recorded in the 12101 ** changeset, and 12102 ** <li> The table has at least as many columns as recorded in the 12103 ** changeset, and 12104 ** <li> The table has primary key columns in the same position as 12105 ** recorded in the changeset. 12106 ** </ul> 12107 ** 12108 ** If there is no compatible table, it is not an error, but none of the 12109 ** changes associated with the table are applied. A warning message is issued 12110 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 12111 ** one such warning is issued for each table in the changeset. 12112 ** 12113 ** For each change for which there is a compatible table, an attempt is made 12114 ** to modify the table contents according to the UPDATE, INSERT or DELETE 12115 ** change. If a change cannot be applied cleanly, the conflict handler 12116 ** function passed as the fifth argument to sqlite3changeset_apply() may be 12117 ** invoked. A description of exactly when the conflict handler is invoked for 12118 ** each type of change is below. 12119 ** 12120 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 12121 ** of passing anything other than a valid function pointer as the xConflict 12122 ** argument are undefined. 12123 ** 12124 ** Each time the conflict handler function is invoked, it must return one 12125 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 12126 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 12127 ** if the second argument passed to the conflict handler is either 12128 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 12129 ** returns an illegal value, any changes already made are rolled back and 12130 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 12131 ** actions are taken by sqlite3changeset_apply() depending on the value 12132 ** returned by each invocation of the conflict-handler function. Refer to 12133 ** the documentation for the three 12134 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 12135 ** 12136 ** <dl> 12137 ** <dt>DELETE Changes<dd> 12138 ** For each DELETE change, the function checks if the target database 12139 ** contains a row with the same primary key value (or values) as the 12140 ** original row values stored in the changeset. If it does, and the values 12141 ** stored in all non-primary key columns also match the values stored in 12142 ** the changeset the row is deleted from the target database. 12143 ** 12144 ** If a row with matching primary key values is found, but one or more of 12145 ** the non-primary key fields contains a value different from the original 12146 ** row value stored in the changeset, the conflict-handler function is 12147 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 12148 ** database table has more columns than are recorded in the changeset, 12149 ** only the values of those non-primary key fields are compared against 12150 ** the current database contents - any trailing database table columns 12151 ** are ignored. 12152 ** 12153 ** If no row with matching primary key values is found in the database, 12154 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12155 ** passed as the second argument. 12156 ** 12157 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 12158 ** (which can only happen if a foreign key constraint is violated), the 12159 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 12160 ** passed as the second argument. This includes the case where the DELETE 12161 ** operation is attempted because an earlier call to the conflict handler 12162 ** function returned [SQLITE_CHANGESET_REPLACE]. 12163 ** 12164 ** <dt>INSERT Changes<dd> 12165 ** For each INSERT change, an attempt is made to insert the new row into 12166 ** the database. If the changeset row contains fewer fields than the 12167 ** database table, the trailing fields are populated with their default 12168 ** values. 12169 ** 12170 ** If the attempt to insert the row fails because the database already 12171 ** contains a row with the same primary key values, the conflict handler 12172 ** function is invoked with the second argument set to 12173 ** [SQLITE_CHANGESET_CONFLICT]. 12174 ** 12175 ** If the attempt to insert the row fails because of some other constraint 12176 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 12177 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 12178 ** This includes the case where the INSERT operation is re-attempted because 12179 ** an earlier call to the conflict handler function returned 12180 ** [SQLITE_CHANGESET_REPLACE]. 12181 ** 12182 ** <dt>UPDATE Changes<dd> 12183 ** For each UPDATE change, the function checks if the target database 12184 ** contains a row with the same primary key value (or values) as the 12185 ** original row values stored in the changeset. If it does, and the values 12186 ** stored in all modified non-primary key columns also match the values 12187 ** stored in the changeset the row is updated within the target database. 12188 ** 12189 ** If a row with matching primary key values is found, but one or more of 12190 ** the modified non-primary key fields contains a value different from an 12191 ** original row value stored in the changeset, the conflict-handler function 12192 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 12193 ** UPDATE changes only contain values for non-primary key fields that are 12194 ** to be modified, only those fields need to match the original values to 12195 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 12196 ** 12197 ** If no row with matching primary key values is found in the database, 12198 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 12199 ** passed as the second argument. 12200 ** 12201 ** If the UPDATE operation is attempted, but SQLite returns 12202 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 12203 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 12204 ** This includes the case where the UPDATE operation is attempted after 12205 ** an earlier call to the conflict handler function returned 12206 ** [SQLITE_CHANGESET_REPLACE]. 12207 ** </dl> 12208 ** 12209 ** It is safe to execute SQL statements, including those that write to the 12210 ** table that the callback related to, from within the xConflict callback. 12211 ** This can be used to further customize the application's conflict 12212 ** resolution strategy. 12213 ** 12214 ** All changes made by these functions are enclosed in a savepoint transaction. 12215 ** If any other error (aside from a constraint failure when attempting to 12216 ** write to the target database) occurs, then the savepoint transaction is 12217 ** rolled back, restoring the target database to its original state, and an 12218 ** SQLite error code returned. 12219 ** 12220 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 12221 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 12222 ** may set (*ppRebase) to point to a "rebase" that may be used with the 12223 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 12224 ** is set to the size of the buffer in bytes. It is the responsibility of the 12225 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 12226 ** is only allocated and populated if one or more conflicts were encountered 12227 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 12228 ** APIs for further details. 12229 ** 12230 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 12231 ** may be modified by passing a combination of 12232 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 12233 ** 12234 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 12235 ** and therefore subject to change. 12236 */ 12237 SQLITE_API int sqlite3changeset_apply( 12238 sqlite3 *db, /* Apply change to "main" db of this handle */ 12239 int nChangeset, /* Size of changeset in bytes */ 12240 void *pChangeset, /* Changeset blob */ 12241 int(*xFilter)( 12242 void *pCtx, /* Copy of sixth arg to _apply() */ 12243 const char *zTab /* Table name */ 12244 ), 12245 int(*xConflict)( 12246 void *pCtx, /* Copy of sixth arg to _apply() */ 12247 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12248 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12249 ), 12250 void *pCtx /* First argument passed to xConflict */ 12251 ); 12252 SQLITE_API int sqlite3changeset_apply_v2( 12253 sqlite3 *db, /* Apply change to "main" db of this handle */ 12254 int nChangeset, /* Size of changeset in bytes */ 12255 void *pChangeset, /* Changeset blob */ 12256 int(*xFilter)( 12257 void *pCtx, /* Copy of sixth arg to _apply() */ 12258 const char *zTab /* Table name */ 12259 ), 12260 int(*xConflict)( 12261 void *pCtx, /* Copy of sixth arg to _apply() */ 12262 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12263 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12264 ), 12265 void *pCtx, /* First argument passed to xConflict */ 12266 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 12267 int flags /* SESSION_CHANGESETAPPLY_* flags */ 12268 ); 12269 12270 /* 12271 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 12272 ** 12273 ** The following flags may passed via the 9th parameter to 12274 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 12275 ** 12276 ** <dl> 12277 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 12278 ** Usually, the sessions module encloses all operations performed by 12279 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 12280 ** SAVEPOINT is committed if the changeset or patchset is successfully 12281 ** applied, or rolled back if an error occurs. Specifying this flag 12282 ** causes the sessions module to omit this savepoint. In this case, if the 12283 ** caller has an open transaction or savepoint when apply_v2() is called, 12284 ** it may revert the partially applied changeset by rolling it back. 12285 ** 12286 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 12287 ** Invert the changeset before applying it. This is equivalent to inverting 12288 ** a changeset using sqlite3changeset_invert() before applying it. It is 12289 ** an error to specify this flag with a patchset. 12290 ** 12291 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd> 12292 ** Do not invoke the conflict handler callback for any changes that 12293 ** would not actually modify the database even if they were applied. 12294 ** Specifically, this means that the conflict handler is not invoked 12295 ** for: 12296 ** <ul> 12297 ** <li>a delete change if the row being deleted cannot be found, 12298 ** <li>an update change if the modified fields are already set to 12299 ** their new values in the conflicting row, or 12300 ** <li>an insert change if all fields of the conflicting row match 12301 ** the row being inserted. 12302 ** </ul> 12303 ** 12304 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd> 12305 ** If this flag it set, then all foreign key constraints in the target 12306 ** database behave as if they were declared with "ON UPDATE NO ACTION ON 12307 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL 12308 ** or SET DEFAULT. 12309 */ 12310 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 12311 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 12312 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004 12313 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008 12314 12315 /* 12316 ** CAPI3REF: Constants Passed To The Conflict Handler 12317 ** 12318 ** Values that may be passed as the second argument to a conflict-handler. 12319 ** 12320 ** <dl> 12321 ** <dt>SQLITE_CHANGESET_DATA<dd> 12322 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 12323 ** when processing a DELETE or UPDATE change if a row with the required 12324 ** PRIMARY KEY fields is present in the database, but one or more other 12325 ** (non primary-key) fields modified by the update do not contain the 12326 ** expected "before" values. 12327 ** 12328 ** The conflicting row, in this case, is the database row with the matching 12329 ** primary key. 12330 ** 12331 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 12332 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 12333 ** argument when processing a DELETE or UPDATE change if a row with the 12334 ** required PRIMARY KEY fields is not present in the database. 12335 ** 12336 ** There is no conflicting row in this case. The results of invoking the 12337 ** sqlite3changeset_conflict() API are undefined. 12338 ** 12339 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 12340 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 12341 ** handler while processing an INSERT change if the operation would result 12342 ** in duplicate primary key values. 12343 ** 12344 ** The conflicting row in this case is the database row with the matching 12345 ** primary key. 12346 ** 12347 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 12348 ** If foreign key handling is enabled, and applying a changeset leaves the 12349 ** database in a state containing foreign key violations, the conflict 12350 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 12351 ** exactly once before the changeset is committed. If the conflict handler 12352 ** returns CHANGESET_OMIT, the changes, including those that caused the 12353 ** foreign key constraint violation, are committed. Or, if it returns 12354 ** CHANGESET_ABORT, the changeset is rolled back. 12355 ** 12356 ** No current or conflicting row information is provided. The only function 12357 ** it is possible to call on the supplied sqlite3_changeset_iter handle 12358 ** is sqlite3changeset_fk_conflicts(). 12359 ** 12360 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 12361 ** If any other constraint violation occurs while applying a change (i.e. 12362 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 12363 ** invoked with CHANGESET_CONSTRAINT as the second argument. 12364 ** 12365 ** There is no conflicting row in this case. The results of invoking the 12366 ** sqlite3changeset_conflict() API are undefined. 12367 ** 12368 ** </dl> 12369 */ 12370 #define SQLITE_CHANGESET_DATA 1 12371 #define SQLITE_CHANGESET_NOTFOUND 2 12372 #define SQLITE_CHANGESET_CONFLICT 3 12373 #define SQLITE_CHANGESET_CONSTRAINT 4 12374 #define SQLITE_CHANGESET_FOREIGN_KEY 5 12375 12376 /* 12377 ** CAPI3REF: Constants Returned By The Conflict Handler 12378 ** 12379 ** A conflict handler callback must return one of the following three values. 12380 ** 12381 ** <dl> 12382 ** <dt>SQLITE_CHANGESET_OMIT<dd> 12383 ** If a conflict handler returns this value no special action is taken. The 12384 ** change that caused the conflict is not applied. The session module 12385 ** continues to the next change in the changeset. 12386 ** 12387 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 12388 ** This value may only be returned if the second argument to the conflict 12389 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 12390 ** is not the case, any changes applied so far are rolled back and the 12391 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 12392 ** 12393 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 12394 ** handler, then the conflicting row is either updated or deleted, depending 12395 ** on the type of change. 12396 ** 12397 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 12398 ** handler, then the conflicting row is removed from the database and a 12399 ** second attempt to apply the change is made. If this second attempt fails, 12400 ** the original row is restored to the database before continuing. 12401 ** 12402 ** <dt>SQLITE_CHANGESET_ABORT<dd> 12403 ** If this value is returned, any changes applied so far are rolled back 12404 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 12405 ** </dl> 12406 */ 12407 #define SQLITE_CHANGESET_OMIT 0 12408 #define SQLITE_CHANGESET_REPLACE 1 12409 #define SQLITE_CHANGESET_ABORT 2 12410 12411 /* 12412 ** CAPI3REF: Rebasing changesets 12413 ** EXPERIMENTAL 12414 ** 12415 ** Suppose there is a site hosting a database in state S0. And that 12416 ** modifications are made that move that database to state S1 and a 12417 ** changeset recorded (the "local" changeset). Then, a changeset based 12418 ** on S0 is received from another site (the "remote" changeset) and 12419 ** applied to the database. The database is then in state 12420 ** (S1+"remote"), where the exact state depends on any conflict 12421 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12422 ** Rebasing a changeset is to update it to take those conflict 12423 ** resolution decisions into account, so that the same conflicts 12424 ** do not have to be resolved elsewhere in the network. 12425 ** 12426 ** For example, if both the local and remote changesets contain an 12427 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12428 ** 12429 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12430 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12431 ** 12432 ** and the conflict resolution is REPLACE, then the INSERT change is 12433 ** removed from the local changeset (it was overridden). Or, if the 12434 ** conflict resolution was "OMIT", then the local changeset is modified 12435 ** to instead contain: 12436 ** 12437 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12438 ** 12439 ** Changes within the local changeset are rebased as follows: 12440 ** 12441 ** <dl> 12442 ** <dt>Local INSERT<dd> 12443 ** This may only conflict with a remote INSERT. If the conflict 12444 ** resolution was OMIT, then add an UPDATE change to the rebased 12445 ** changeset. Or, if the conflict resolution was REPLACE, add 12446 ** nothing to the rebased changeset. 12447 ** 12448 ** <dt>Local DELETE<dd> 12449 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12450 ** only possible resolution is OMIT. If the remote operation was a 12451 ** DELETE, then add no change to the rebased changeset. If the remote 12452 ** operation was an UPDATE, then the old.* fields of change are updated 12453 ** to reflect the new.* values in the UPDATE. 12454 ** 12455 ** <dt>Local UPDATE<dd> 12456 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12457 ** with a DELETE, and the conflict resolution was OMIT, then the update 12458 ** is changed into an INSERT. Any undefined values in the new.* record 12459 ** from the update change are filled in using the old.* values from 12460 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12461 ** the UPDATE change is simply omitted from the rebased changeset. 12462 ** 12463 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12464 ** the old.* values are rebased using the new.* values in the remote 12465 ** change. Or, if the resolution is REPLACE, then the change is copied 12466 ** into the rebased changeset with updates to columns also updated by 12467 ** the conflicting remote UPDATE removed. If this means no columns would 12468 ** be updated, the change is omitted. 12469 ** </dl> 12470 ** 12471 ** A local change may be rebased against multiple remote changes 12472 ** simultaneously. If a single key is modified by multiple remote 12473 ** changesets, they are combined as follows before the local changeset 12474 ** is rebased: 12475 ** 12476 ** <ul> 12477 ** <li> If there has been one or more REPLACE resolutions on a 12478 ** key, it is rebased according to a REPLACE. 12479 ** 12480 ** <li> If there have been no REPLACE resolutions on a key, then 12481 ** the local changeset is rebased according to the most recent 12482 ** of the OMIT resolutions. 12483 ** </ul> 12484 ** 12485 ** Note that conflict resolutions from multiple remote changesets are 12486 ** combined on a per-field basis, not per-row. This means that in the 12487 ** case of multiple remote UPDATE operations, some fields of a single 12488 ** local change may be rebased for REPLACE while others are rebased for 12489 ** OMIT. 12490 ** 12491 ** In order to rebase a local changeset, the remote changeset must first 12492 ** be applied to the local database using sqlite3changeset_apply_v2() and 12493 ** the buffer of rebase information captured. Then: 12494 ** 12495 ** <ol> 12496 ** <li> An sqlite3_rebaser object is created by calling 12497 ** sqlite3rebaser_create(). 12498 ** <li> The new object is configured with the rebase buffer obtained from 12499 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12500 ** If the local changeset is to be rebased against multiple remote 12501 ** changesets, then sqlite3rebaser_configure() should be called 12502 ** multiple times, in the same order that the multiple 12503 ** sqlite3changeset_apply_v2() calls were made. 12504 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12505 ** <li> The sqlite3_rebaser object is deleted by calling 12506 ** sqlite3rebaser_delete(). 12507 ** </ol> 12508 */ 12509 typedef struct sqlite3_rebaser sqlite3_rebaser; 12510 12511 /* 12512 ** CAPI3REF: Create a changeset rebaser object. 12513 ** EXPERIMENTAL 12514 ** 12515 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12516 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12517 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12518 ** to NULL. 12519 */ 12520 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12521 12522 /* 12523 ** CAPI3REF: Configure a changeset rebaser object. 12524 ** EXPERIMENTAL 12525 ** 12526 ** Configure the changeset rebaser object to rebase changesets according 12527 ** to the conflict resolutions described by buffer pRebase (size nRebase 12528 ** bytes), which must have been obtained from a previous call to 12529 ** sqlite3changeset_apply_v2(). 12530 */ 12531 SQLITE_API int sqlite3rebaser_configure( 12532 sqlite3_rebaser*, 12533 int nRebase, const void *pRebase 12534 ); 12535 12536 /* 12537 ** CAPI3REF: Rebase a changeset 12538 ** EXPERIMENTAL 12539 ** 12540 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12541 ** in size. This function allocates and populates a buffer with a copy 12542 ** of the changeset rebased according to the configuration of the 12543 ** rebaser object passed as the first argument. If successful, (*ppOut) 12544 ** is set to point to the new buffer containing the rebased changeset and 12545 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12546 ** responsibility of the caller to eventually free the new buffer using 12547 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12548 ** are set to zero and an SQLite error code returned. 12549 */ 12550 SQLITE_API int sqlite3rebaser_rebase( 12551 sqlite3_rebaser*, 12552 int nIn, const void *pIn, 12553 int *pnOut, void **ppOut 12554 ); 12555 12556 /* 12557 ** CAPI3REF: Delete a changeset rebaser object. 12558 ** EXPERIMENTAL 12559 ** 12560 ** Delete the changeset rebaser object and all associated resources. There 12561 ** should be one call to this function for each successful invocation 12562 ** of sqlite3rebaser_create(). 12563 */ 12564 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12565 12566 /* 12567 ** CAPI3REF: Streaming Versions of API functions. 12568 ** 12569 ** The six streaming API xxx_strm() functions serve similar purposes to the 12570 ** corresponding non-streaming API functions: 12571 ** 12572 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12573 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12574 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12575 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12576 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12577 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12578 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12579 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12580 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12581 ** </table> 12582 ** 12583 ** Non-streaming functions that accept changesets (or patchsets) as input 12584 ** require that the entire changeset be stored in a single buffer in memory. 12585 ** Similarly, those that return a changeset or patchset do so by returning 12586 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12587 ** Normally this is convenient. However, if an application running in a 12588 ** low-memory environment is required to handle very large changesets, the 12589 ** large contiguous memory allocations required can become onerous. 12590 ** 12591 ** In order to avoid this problem, instead of a single large buffer, input 12592 ** is passed to a streaming API functions by way of a callback function that 12593 ** the sessions module invokes to incrementally request input data as it is 12594 ** required. In all cases, a pair of API function parameters such as 12595 ** 12596 ** <pre> 12597 ** int nChangeset, 12598 ** void *pChangeset, 12599 ** </pre> 12600 ** 12601 ** Is replaced by: 12602 ** 12603 ** <pre> 12604 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12605 ** void *pIn, 12606 ** </pre> 12607 ** 12608 ** Each time the xInput callback is invoked by the sessions module, the first 12609 ** argument passed is a copy of the supplied pIn context pointer. The second 12610 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12611 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12612 ** into the buffer and set (*pnData) to the actual number of bytes copied 12613 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12614 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12615 ** error code should be returned. In all cases, if an xInput callback returns 12616 ** an error, all processing is abandoned and the streaming API function 12617 ** returns a copy of the error code to the caller. 12618 ** 12619 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12620 ** invoked by the sessions module at any point during the lifetime of the 12621 ** iterator. If such an xInput callback returns an error, the iterator enters 12622 ** an error state, whereby all subsequent calls to iterator functions 12623 ** immediately fail with the same error code as returned by xInput. 12624 ** 12625 ** Similarly, streaming API functions that return changesets (or patchsets) 12626 ** return them in chunks by way of a callback function instead of via a 12627 ** pointer to a single large buffer. In this case, a pair of parameters such 12628 ** as: 12629 ** 12630 ** <pre> 12631 ** int *pnChangeset, 12632 ** void **ppChangeset, 12633 ** </pre> 12634 ** 12635 ** Is replaced by: 12636 ** 12637 ** <pre> 12638 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12639 ** void *pOut 12640 ** </pre> 12641 ** 12642 ** The xOutput callback is invoked zero or more times to return data to 12643 ** the application. The first parameter passed to each call is a copy of the 12644 ** pOut pointer supplied by the application. The second parameter, pData, 12645 ** points to a buffer nData bytes in size containing the chunk of output 12646 ** data being returned. If the xOutput callback successfully processes the 12647 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12648 ** it should return some other SQLite error code. In this case processing 12649 ** is immediately abandoned and the streaming API function returns a copy 12650 ** of the xOutput error code to the application. 12651 ** 12652 ** The sessions module never invokes an xOutput callback with the third 12653 ** parameter set to a value less than or equal to zero. Other than this, 12654 ** no guarantees are made as to the size of the chunks of data returned. 12655 */ 12656 SQLITE_API int sqlite3changeset_apply_strm( 12657 sqlite3 *db, /* Apply change to "main" db of this handle */ 12658 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12659 void *pIn, /* First arg for xInput */ 12660 int(*xFilter)( 12661 void *pCtx, /* Copy of sixth arg to _apply() */ 12662 const char *zTab /* Table name */ 12663 ), 12664 int(*xConflict)( 12665 void *pCtx, /* Copy of sixth arg to _apply() */ 12666 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12667 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12668 ), 12669 void *pCtx /* First argument passed to xConflict */ 12670 ); 12671 SQLITE_API int sqlite3changeset_apply_v2_strm( 12672 sqlite3 *db, /* Apply change to "main" db of this handle */ 12673 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12674 void *pIn, /* First arg for xInput */ 12675 int(*xFilter)( 12676 void *pCtx, /* Copy of sixth arg to _apply() */ 12677 const char *zTab /* Table name */ 12678 ), 12679 int(*xConflict)( 12680 void *pCtx, /* Copy of sixth arg to _apply() */ 12681 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12682 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12683 ), 12684 void *pCtx, /* First argument passed to xConflict */ 12685 void **ppRebase, int *pnRebase, 12686 int flags 12687 ); 12688 SQLITE_API int sqlite3changeset_concat_strm( 12689 int (*xInputA)(void *pIn, void *pData, int *pnData), 12690 void *pInA, 12691 int (*xInputB)(void *pIn, void *pData, int *pnData), 12692 void *pInB, 12693 int (*xOutput)(void *pOut, const void *pData, int nData), 12694 void *pOut 12695 ); 12696 SQLITE_API int sqlite3changeset_invert_strm( 12697 int (*xInput)(void *pIn, void *pData, int *pnData), 12698 void *pIn, 12699 int (*xOutput)(void *pOut, const void *pData, int nData), 12700 void *pOut 12701 ); 12702 SQLITE_API int sqlite3changeset_start_strm( 12703 sqlite3_changeset_iter **pp, 12704 int (*xInput)(void *pIn, void *pData, int *pnData), 12705 void *pIn 12706 ); 12707 SQLITE_API int sqlite3changeset_start_v2_strm( 12708 sqlite3_changeset_iter **pp, 12709 int (*xInput)(void *pIn, void *pData, int *pnData), 12710 void *pIn, 12711 int flags 12712 ); 12713 SQLITE_API int sqlite3session_changeset_strm( 12714 sqlite3_session *pSession, 12715 int (*xOutput)(void *pOut, const void *pData, int nData), 12716 void *pOut 12717 ); 12718 SQLITE_API int sqlite3session_patchset_strm( 12719 sqlite3_session *pSession, 12720 int (*xOutput)(void *pOut, const void *pData, int nData), 12721 void *pOut 12722 ); 12723 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12724 int (*xInput)(void *pIn, void *pData, int *pnData), 12725 void *pIn 12726 ); 12727 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12728 int (*xOutput)(void *pOut, const void *pData, int nData), 12729 void *pOut 12730 ); 12731 SQLITE_API int sqlite3rebaser_rebase_strm( 12732 sqlite3_rebaser *pRebaser, 12733 int (*xInput)(void *pIn, void *pData, int *pnData), 12734 void *pIn, 12735 int (*xOutput)(void *pOut, const void *pData, int nData), 12736 void *pOut 12737 ); 12738 12739 /* 12740 ** CAPI3REF: Configure global parameters 12741 ** 12742 ** The sqlite3session_config() interface is used to make global configuration 12743 ** changes to the sessions module in order to tune it to the specific needs 12744 ** of the application. 12745 ** 12746 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12747 ** while any other thread is inside any other sessions method then the 12748 ** results are undefined. Furthermore, if it is invoked after any sessions 12749 ** related objects have been created, the results are also undefined. 12750 ** 12751 ** The first argument to the sqlite3session_config() function must be one 12752 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12753 ** interpretation of the (void*) value passed as the second parameter and 12754 ** the effect of calling this function depends on the value of the first 12755 ** parameter. 12756 ** 12757 ** <dl> 12758 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12759 ** By default, the sessions module streaming interfaces attempt to input 12760 ** and output data in approximately 1 KiB chunks. This operand may be used 12761 ** to set and query the value of this configuration setting. The pointer 12762 ** passed as the second argument must point to a value of type (int). 12763 ** If this value is greater than 0, it is used as the new streaming data 12764 ** chunk size for both input and output. Before returning, the (int) value 12765 ** pointed to by pArg is set to the final value of the streaming interface 12766 ** chunk size. 12767 ** </dl> 12768 ** 12769 ** This function returns SQLITE_OK if successful, or an SQLite error code 12770 ** otherwise. 12771 */ 12772 SQLITE_API int sqlite3session_config(int op, void *pArg); 12773 12774 /* 12775 ** CAPI3REF: Values for sqlite3session_config(). 12776 */ 12777 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12778 12779 /* 12780 ** Make sure we can call this stuff from C++. 12781 */ 12782 #ifdef __cplusplus 12783 } 12784 #endif 12785 12786 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12787 12788 /******** End of sqlite3session.h *********/ 12789 /******** Begin file fts5.h *********/ 12790 /* 12791 ** 2014 May 31 12792 ** 12793 ** The author disclaims copyright to this source code. In place of 12794 ** a legal notice, here is a blessing: 12795 ** 12796 ** May you do good and not evil. 12797 ** May you find forgiveness for yourself and forgive others. 12798 ** May you share freely, never taking more than you give. 12799 ** 12800 ****************************************************************************** 12801 ** 12802 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12803 ** FTS5 may be extended with: 12804 ** 12805 ** * custom tokenizers, and 12806 ** * custom auxiliary functions. 12807 */ 12808 12809 12810 #ifndef _FTS5_H 12811 #define _FTS5_H 12812 12813 12814 #ifdef __cplusplus 12815 extern "C" { 12816 #endif 12817 12818 /************************************************************************* 12819 ** CUSTOM AUXILIARY FUNCTIONS 12820 ** 12821 ** Virtual table implementations may overload SQL functions by implementing 12822 ** the sqlite3_module.xFindFunction() method. 12823 */ 12824 12825 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12826 typedef struct Fts5Context Fts5Context; 12827 typedef struct Fts5PhraseIter Fts5PhraseIter; 12828 12829 typedef void (*fts5_extension_function)( 12830 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12831 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12832 sqlite3_context *pCtx, /* Context for returning result/error */ 12833 int nVal, /* Number of values in apVal[] array */ 12834 sqlite3_value **apVal /* Array of trailing arguments */ 12835 ); 12836 12837 struct Fts5PhraseIter { 12838 const unsigned char *a; 12839 const unsigned char *b; 12840 }; 12841 12842 /* 12843 ** EXTENSION API FUNCTIONS 12844 ** 12845 ** xUserData(pFts): 12846 ** Return a copy of the context pointer the extension function was 12847 ** registered with. 12848 ** 12849 ** xColumnTotalSize(pFts, iCol, pnToken): 12850 ** If parameter iCol is less than zero, set output variable *pnToken 12851 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12852 ** non-negative but less than the number of columns in the table, return 12853 ** the total number of tokens in column iCol, considering all rows in 12854 ** the FTS5 table. 12855 ** 12856 ** If parameter iCol is greater than or equal to the number of columns 12857 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12858 ** an OOM condition or IO error), an appropriate SQLite error code is 12859 ** returned. 12860 ** 12861 ** xColumnCount(pFts): 12862 ** Return the number of columns in the table. 12863 ** 12864 ** xColumnSize(pFts, iCol, pnToken): 12865 ** If parameter iCol is less than zero, set output variable *pnToken 12866 ** to the total number of tokens in the current row. Or, if iCol is 12867 ** non-negative but less than the number of columns in the table, set 12868 ** *pnToken to the number of tokens in column iCol of the current row. 12869 ** 12870 ** If parameter iCol is greater than or equal to the number of columns 12871 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12872 ** an OOM condition or IO error), an appropriate SQLite error code is 12873 ** returned. 12874 ** 12875 ** This function may be quite inefficient if used with an FTS5 table 12876 ** created with the "columnsize=0" option. 12877 ** 12878 ** xColumnText: 12879 ** This function attempts to retrieve the text of column iCol of the 12880 ** current document. If successful, (*pz) is set to point to a buffer 12881 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12882 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12883 ** if an error occurs, an SQLite error code is returned and the final values 12884 ** of (*pz) and (*pn) are undefined. 12885 ** 12886 ** xPhraseCount: 12887 ** Returns the number of phrases in the current query expression. 12888 ** 12889 ** xPhraseSize: 12890 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 12891 ** are numbered starting from zero. 12892 ** 12893 ** xInstCount: 12894 ** Set *pnInst to the total number of occurrences of all phrases within 12895 ** the query within the current row. Return SQLITE_OK if successful, or 12896 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12897 ** 12898 ** This API can be quite slow if used with an FTS5 table created with the 12899 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12900 ** with either "detail=none" or "detail=column" and "content=" option 12901 ** (i.e. if it is a contentless table), then this API always returns 0. 12902 ** 12903 ** xInst: 12904 ** Query for the details of phrase match iIdx within the current row. 12905 ** Phrase matches are numbered starting from zero, so the iIdx argument 12906 ** should be greater than or equal to zero and smaller than the value 12907 ** output by xInstCount(). 12908 ** 12909 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12910 ** to the column in which it occurs and *piOff the token offset of the 12911 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 12912 ** code (i.e. SQLITE_NOMEM) if an error occurs. 12913 ** 12914 ** This API can be quite slow if used with an FTS5 table created with the 12915 ** "detail=none" or "detail=column" option. 12916 ** 12917 ** xRowid: 12918 ** Returns the rowid of the current row. 12919 ** 12920 ** xTokenize: 12921 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12922 ** 12923 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12924 ** This API function is used to query the FTS table for phrase iPhrase 12925 ** of the current query. Specifically, a query equivalent to: 12926 ** 12927 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12928 ** 12929 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12930 ** current query is executed. Any column filter that applies to 12931 ** phrase iPhrase of the current query is included in $p. For each 12932 ** row visited, the callback function passed as the fourth argument 12933 ** is invoked. The context and API objects passed to the callback 12934 ** function may be used to access the properties of each matched row. 12935 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12936 ** the third argument to pUserData. 12937 ** 12938 ** If the callback function returns any value other than SQLITE_OK, the 12939 ** query is abandoned and the xQueryPhrase function returns immediately. 12940 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12941 ** Otherwise, the error code is propagated upwards. 12942 ** 12943 ** If the query runs to completion without incident, SQLITE_OK is returned. 12944 ** Or, if some error occurs before the query completes or is aborted by 12945 ** the callback, an SQLite error code is returned. 12946 ** 12947 ** 12948 ** xSetAuxdata(pFts5, pAux, xDelete) 12949 ** 12950 ** Save the pointer passed as the second argument as the extension function's 12951 ** "auxiliary data". The pointer may then be retrieved by the current or any 12952 ** future invocation of the same fts5 extension function made as part of 12953 ** the same MATCH query using the xGetAuxdata() API. 12954 ** 12955 ** Each extension function is allocated a single auxiliary data slot for 12956 ** each FTS query (MATCH expression). If the extension function is invoked 12957 ** more than once for a single FTS query, then all invocations share a 12958 ** single auxiliary data context. 12959 ** 12960 ** If there is already an auxiliary data pointer when this function is 12961 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12962 ** was specified along with the original pointer, it is invoked at this 12963 ** point. 12964 ** 12965 ** The xDelete callback, if one is specified, is also invoked on the 12966 ** auxiliary data pointer after the FTS5 query has finished. 12967 ** 12968 ** If an error (e.g. an OOM condition) occurs within this function, 12969 ** the auxiliary data is set to NULL and an error code returned. If the 12970 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12971 ** pointer before returning. 12972 ** 12973 ** 12974 ** xGetAuxdata(pFts5, bClear) 12975 ** 12976 ** Returns the current auxiliary data pointer for the fts5 extension 12977 ** function. See the xSetAuxdata() method for details. 12978 ** 12979 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12980 ** (set to NULL) before this function returns. In this case the xDelete, 12981 ** if any, is not invoked. 12982 ** 12983 ** 12984 ** xRowCount(pFts5, pnRow) 12985 ** 12986 ** This function is used to retrieve the total number of rows in the table. 12987 ** In other words, the same value that would be returned by: 12988 ** 12989 ** SELECT count(*) FROM ftstable; 12990 ** 12991 ** xPhraseFirst() 12992 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12993 ** method, to iterate through all instances of a single query phrase within 12994 ** the current row. This is the same information as is accessible via the 12995 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12996 ** to use, this API may be faster under some circumstances. To iterate 12997 ** through instances of phrase iPhrase, use the following code: 12998 ** 12999 ** Fts5PhraseIter iter; 13000 ** int iCol, iOff; 13001 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 13002 ** iCol>=0; 13003 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 13004 ** ){ 13005 ** // An instance of phrase iPhrase at offset iOff of column iCol 13006 ** } 13007 ** 13008 ** The Fts5PhraseIter structure is defined above. Applications should not 13009 ** modify this structure directly - it should only be used as shown above 13010 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 13011 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 13012 ** 13013 ** This API can be quite slow if used with an FTS5 table created with the 13014 ** "detail=none" or "detail=column" option. If the FTS5 table is created 13015 ** with either "detail=none" or "detail=column" and "content=" option 13016 ** (i.e. if it is a contentless table), then this API always iterates 13017 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 13018 ** 13019 ** xPhraseNext() 13020 ** See xPhraseFirst above. 13021 ** 13022 ** xPhraseFirstColumn() 13023 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 13024 ** and xPhraseNext() APIs described above. The difference is that instead 13025 ** of iterating through all instances of a phrase in the current row, these 13026 ** APIs are used to iterate through the set of columns in the current row 13027 ** that contain one or more instances of a specified phrase. For example: 13028 ** 13029 ** Fts5PhraseIter iter; 13030 ** int iCol; 13031 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 13032 ** iCol>=0; 13033 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 13034 ** ){ 13035 ** // Column iCol contains at least one instance of phrase iPhrase 13036 ** } 13037 ** 13038 ** This API can be quite slow if used with an FTS5 table created with the 13039 ** "detail=none" option. If the FTS5 table is created with either 13040 ** "detail=none" "content=" option (i.e. if it is a contentless table), 13041 ** then this API always iterates through an empty set (all calls to 13042 ** xPhraseFirstColumn() set iCol to -1). 13043 ** 13044 ** The information accessed using this API and its companion 13045 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 13046 ** (or xInst/xInstCount). The chief advantage of this API is that it is 13047 ** significantly more efficient than those alternatives when used with 13048 ** "detail=column" tables. 13049 ** 13050 ** xPhraseNextColumn() 13051 ** See xPhraseFirstColumn above. 13052 */ 13053 struct Fts5ExtensionApi { 13054 int iVersion; /* Currently always set to 2 */ 13055 13056 void *(*xUserData)(Fts5Context*); 13057 13058 int (*xColumnCount)(Fts5Context*); 13059 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 13060 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 13061 13062 int (*xTokenize)(Fts5Context*, 13063 const char *pText, int nText, /* Text to tokenize */ 13064 void *pCtx, /* Context passed to xToken() */ 13065 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 13066 ); 13067 13068 int (*xPhraseCount)(Fts5Context*); 13069 int (*xPhraseSize)(Fts5Context*, int iPhrase); 13070 13071 int (*xInstCount)(Fts5Context*, int *pnInst); 13072 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 13073 13074 sqlite3_int64 (*xRowid)(Fts5Context*); 13075 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 13076 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 13077 13078 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 13079 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 13080 ); 13081 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 13082 void *(*xGetAuxdata)(Fts5Context*, int bClear); 13083 13084 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 13085 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 13086 13087 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 13088 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 13089 }; 13090 13091 /* 13092 ** CUSTOM AUXILIARY FUNCTIONS 13093 *************************************************************************/ 13094 13095 /************************************************************************* 13096 ** CUSTOM TOKENIZERS 13097 ** 13098 ** Applications may also register custom tokenizer types. A tokenizer 13099 ** is registered by providing fts5 with a populated instance of the 13100 ** following structure. All structure methods must be defined, setting 13101 ** any member of the fts5_tokenizer struct to NULL leads to undefined 13102 ** behaviour. The structure methods are expected to function as follows: 13103 ** 13104 ** xCreate: 13105 ** This function is used to allocate and initialize a tokenizer instance. 13106 ** A tokenizer instance is required to actually tokenize text. 13107 ** 13108 ** The first argument passed to this function is a copy of the (void*) 13109 ** pointer provided by the application when the fts5_tokenizer object 13110 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 13111 ** The second and third arguments are an array of nul-terminated strings 13112 ** containing the tokenizer arguments, if any, specified following the 13113 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 13114 ** to create the FTS5 table. 13115 ** 13116 ** The final argument is an output variable. If successful, (*ppOut) 13117 ** should be set to point to the new tokenizer handle and SQLITE_OK 13118 ** returned. If an error occurs, some value other than SQLITE_OK should 13119 ** be returned. In this case, fts5 assumes that the final value of *ppOut 13120 ** is undefined. 13121 ** 13122 ** xDelete: 13123 ** This function is invoked to delete a tokenizer handle previously 13124 ** allocated using xCreate(). Fts5 guarantees that this function will 13125 ** be invoked exactly once for each successful call to xCreate(). 13126 ** 13127 ** xTokenize: 13128 ** This function is expected to tokenize the nText byte string indicated 13129 ** by argument pText. pText may or may not be nul-terminated. The first 13130 ** argument passed to this function is a pointer to an Fts5Tokenizer object 13131 ** returned by an earlier call to xCreate(). 13132 ** 13133 ** The second argument indicates the reason that FTS5 is requesting 13134 ** tokenization of the supplied text. This is always one of the following 13135 ** four values: 13136 ** 13137 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 13138 ** or removed from the FTS table. The tokenizer is being invoked to 13139 ** determine the set of tokens to add to (or delete from) the 13140 ** FTS index. 13141 ** 13142 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 13143 ** against the FTS index. The tokenizer is being called to tokenize 13144 ** a bareword or quoted string specified as part of the query. 13145 ** 13146 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 13147 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 13148 ** followed by a "*" character, indicating that the last token 13149 ** returned by the tokenizer will be treated as a token prefix. 13150 ** 13151 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 13152 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 13153 ** function. Or an fts5_api.xColumnSize() request made by the same 13154 ** on a columnsize=0 database. 13155 ** </ul> 13156 ** 13157 ** For each token in the input string, the supplied callback xToken() must 13158 ** be invoked. The first argument to it should be a copy of the pointer 13159 ** passed as the second argument to xTokenize(). The third and fourth 13160 ** arguments are a pointer to a buffer containing the token text, and the 13161 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 13162 ** of the first byte of and first byte immediately following the text from 13163 ** which the token is derived within the input. 13164 ** 13165 ** The second argument passed to the xToken() callback ("tflags") should 13166 ** normally be set to 0. The exception is if the tokenizer supports 13167 ** synonyms. In this case see the discussion below for details. 13168 ** 13169 ** FTS5 assumes the xToken() callback is invoked for each token in the 13170 ** order that they occur within the input text. 13171 ** 13172 ** If an xToken() callback returns any value other than SQLITE_OK, then 13173 ** the tokenization should be abandoned and the xTokenize() method should 13174 ** immediately return a copy of the xToken() return value. Or, if the 13175 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 13176 ** if an error occurs with the xTokenize() implementation itself, it 13177 ** may abandon the tokenization and return any error code other than 13178 ** SQLITE_OK or SQLITE_DONE. 13179 ** 13180 ** SYNONYM SUPPORT 13181 ** 13182 ** Custom tokenizers may also support synonyms. Consider a case in which a 13183 ** user wishes to query for a phrase such as "first place". Using the 13184 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 13185 ** of "first place" within the document set, but not alternative forms 13186 ** such as "1st place". In some applications, it would be better to match 13187 ** all instances of "first place" or "1st place" regardless of which form 13188 ** the user specified in the MATCH query text. 13189 ** 13190 ** There are several ways to approach this in FTS5: 13191 ** 13192 ** <ol><li> By mapping all synonyms to a single token. In this case, using 13193 ** the above example, this means that the tokenizer returns the 13194 ** same token for inputs "first" and "1st". Say that token is in 13195 ** fact "first", so that when the user inserts the document "I won 13196 ** 1st place" entries are added to the index for tokens "i", "won", 13197 ** "first" and "place". If the user then queries for '1st + place', 13198 ** the tokenizer substitutes "first" for "1st" and the query works 13199 ** as expected. 13200 ** 13201 ** <li> By querying the index for all synonyms of each query term 13202 ** separately. In this case, when tokenizing query text, the 13203 ** tokenizer may provide multiple synonyms for a single term 13204 ** within the document. FTS5 then queries the index for each 13205 ** synonym individually. For example, faced with the query: 13206 ** 13207 ** <codeblock> 13208 ** ... MATCH 'first place'</codeblock> 13209 ** 13210 ** the tokenizer offers both "1st" and "first" as synonyms for the 13211 ** first token in the MATCH query and FTS5 effectively runs a query 13212 ** similar to: 13213 ** 13214 ** <codeblock> 13215 ** ... MATCH '(first OR 1st) place'</codeblock> 13216 ** 13217 ** except that, for the purposes of auxiliary functions, the query 13218 ** still appears to contain just two phrases - "(first OR 1st)" 13219 ** being treated as a single phrase. 13220 ** 13221 ** <li> By adding multiple synonyms for a single term to the FTS index. 13222 ** Using this method, when tokenizing document text, the tokenizer 13223 ** provides multiple synonyms for each token. So that when a 13224 ** document such as "I won first place" is tokenized, entries are 13225 ** added to the FTS index for "i", "won", "first", "1st" and 13226 ** "place". 13227 ** 13228 ** This way, even if the tokenizer does not provide synonyms 13229 ** when tokenizing query text (it should not - to do so would be 13230 ** inefficient), it doesn't matter if the user queries for 13231 ** 'first + place' or '1st + place', as there are entries in the 13232 ** FTS index corresponding to both forms of the first token. 13233 ** </ol> 13234 ** 13235 ** Whether it is parsing document or query text, any call to xToken that 13236 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 13237 ** is considered to supply a synonym for the previous token. For example, 13238 ** when parsing the document "I won first place", a tokenizer that supports 13239 ** synonyms would call xToken() 5 times, as follows: 13240 ** 13241 ** <codeblock> 13242 ** xToken(pCtx, 0, "i", 1, 0, 1); 13243 ** xToken(pCtx, 0, "won", 3, 2, 5); 13244 ** xToken(pCtx, 0, "first", 5, 6, 11); 13245 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 13246 ** xToken(pCtx, 0, "place", 5, 12, 17); 13247 **</codeblock> 13248 ** 13249 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 13250 ** xToken() is called. Multiple synonyms may be specified for a single token 13251 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 13252 ** There is no limit to the number of synonyms that may be provided for a 13253 ** single token. 13254 ** 13255 ** In many cases, method (1) above is the best approach. It does not add 13256 ** extra data to the FTS index or require FTS5 to query for multiple terms, 13257 ** so it is efficient in terms of disk space and query speed. However, it 13258 ** does not support prefix queries very well. If, as suggested above, the 13259 ** token "first" is substituted for "1st" by the tokenizer, then the query: 13260 ** 13261 ** <codeblock> 13262 ** ... MATCH '1s*'</codeblock> 13263 ** 13264 ** will not match documents that contain the token "1st" (as the tokenizer 13265 ** will probably not map "1s" to any prefix of "first"). 13266 ** 13267 ** For full prefix support, method (3) may be preferred. In this case, 13268 ** because the index contains entries for both "first" and "1st", prefix 13269 ** queries such as 'fi*' or '1s*' will match correctly. However, because 13270 ** extra entries are added to the FTS index, this method uses more space 13271 ** within the database. 13272 ** 13273 ** Method (2) offers a midpoint between (1) and (3). Using this method, 13274 ** a query such as '1s*' will match documents that contain the literal 13275 ** token "1st", but not "first" (assuming the tokenizer is not able to 13276 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 13277 ** will match against "1st" and "first". This method does not require 13278 ** extra disk space, as no extra entries are added to the FTS index. 13279 ** On the other hand, it may require more CPU cycles to run MATCH queries, 13280 ** as separate queries of the FTS index are required for each synonym. 13281 ** 13282 ** When using methods (2) or (3), it is important that the tokenizer only 13283 ** provide synonyms when tokenizing document text (method (3)) or query 13284 ** text (method (2)), not both. Doing so will not cause any errors, but is 13285 ** inefficient. 13286 */ 13287 typedef struct Fts5Tokenizer Fts5Tokenizer; 13288 typedef struct fts5_tokenizer fts5_tokenizer; 13289 struct fts5_tokenizer { 13290 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 13291 void (*xDelete)(Fts5Tokenizer*); 13292 int (*xTokenize)(Fts5Tokenizer*, 13293 void *pCtx, 13294 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 13295 const char *pText, int nText, 13296 int (*xToken)( 13297 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 13298 int tflags, /* Mask of FTS5_TOKEN_* flags */ 13299 const char *pToken, /* Pointer to buffer containing token */ 13300 int nToken, /* Size of token in bytes */ 13301 int iStart, /* Byte offset of token within input text */ 13302 int iEnd /* Byte offset of end of token within input text */ 13303 ) 13304 ); 13305 }; 13306 13307 /* Flags that may be passed as the third argument to xTokenize() */ 13308 #define FTS5_TOKENIZE_QUERY 0x0001 13309 #define FTS5_TOKENIZE_PREFIX 0x0002 13310 #define FTS5_TOKENIZE_DOCUMENT 0x0004 13311 #define FTS5_TOKENIZE_AUX 0x0008 13312 13313 /* Flags that may be passed by the tokenizer implementation back to FTS5 13314 ** as the third argument to the supplied xToken callback. */ 13315 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 13316 13317 /* 13318 ** END OF CUSTOM TOKENIZERS 13319 *************************************************************************/ 13320 13321 /************************************************************************* 13322 ** FTS5 EXTENSION REGISTRATION API 13323 */ 13324 typedef struct fts5_api fts5_api; 13325 struct fts5_api { 13326 int iVersion; /* Currently always set to 2 */ 13327 13328 /* Create a new tokenizer */ 13329 int (*xCreateTokenizer)( 13330 fts5_api *pApi, 13331 const char *zName, 13332 void *pUserData, 13333 fts5_tokenizer *pTokenizer, 13334 void (*xDestroy)(void*) 13335 ); 13336 13337 /* Find an existing tokenizer */ 13338 int (*xFindTokenizer)( 13339 fts5_api *pApi, 13340 const char *zName, 13341 void **ppUserData, 13342 fts5_tokenizer *pTokenizer 13343 ); 13344 13345 /* Create a new auxiliary function */ 13346 int (*xCreateFunction)( 13347 fts5_api *pApi, 13348 const char *zName, 13349 void *pUserData, 13350 fts5_extension_function xFunction, 13351 void (*xDestroy)(void*) 13352 ); 13353 }; 13354 13355 /* 13356 ** END OF REGISTRATION API 13357 *************************************************************************/ 13358 13359 #ifdef __cplusplus 13360 } /* end of the 'extern "C"' block */ 13361 #endif 13362 13363 #endif /* _FTS5_H */ 13364 13365 /******** End of fts5.h *********/ 13366