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 "3.40.1" 150 #define SQLITE_VERSION_NUMBER 3040001 151 #define SQLITE_SOURCE_ID "2022-12-28 14:03:47 df5c253c0b3dd24916e4ec7cf77d3db5294cc9fd45ae7b9c5e82ad8197f38a24" 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_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 532 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 533 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 534 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 535 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 536 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 537 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 538 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 539 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 540 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 541 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 542 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 543 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 544 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 545 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 546 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 547 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 548 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 549 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 550 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 551 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 552 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 553 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 554 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 555 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 556 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 557 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 558 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 559 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 560 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 561 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 562 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 563 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 564 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 565 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 566 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 567 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 568 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 569 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 570 571 /* 572 ** CAPI3REF: Flags For File Open Operations 573 ** 574 ** These bit values are intended for use in the 575 ** 3rd parameter to the [sqlite3_open_v2()] interface and 576 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 577 ** 578 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be 579 ** used as the third argument to the [sqlite3_open_v2()] interface. 580 ** The other flags have historically been ignored by sqlite3_open_v2(), 581 ** though future versions of SQLite might change so that an error is 582 ** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 583 ** Applications should not depend on the historical behavior. 584 ** 585 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 586 ** [sqlite3_open_v2()] does *not* cause the underlying database file 587 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 588 ** [sqlite3_open_v2()] has historically be a no-op and might become an 589 ** error in future versions of SQLite. 590 */ 591 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 592 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 593 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 594 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 595 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 596 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 597 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 598 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 599 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 600 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 601 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 602 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 603 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 604 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 605 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 606 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 607 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 608 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 609 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 610 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 611 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 612 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 613 614 /* Reserved: 0x00F00000 */ 615 /* Legacy compatibility: */ 616 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 617 618 619 /* 620 ** CAPI3REF: Device Characteristics 621 ** 622 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 623 ** object returns an integer which is a vector of these 624 ** bit values expressing I/O characteristics of the mass storage 625 ** device that holds the file that the [sqlite3_io_methods] 626 ** refers to. 627 ** 628 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 629 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 630 ** mean that writes of blocks that are nnn bytes in size and 631 ** are aligned to an address which is an integer multiple of 632 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 633 ** that when data is appended to a file, the data is appended 634 ** first then the size of the file is extended, never the other 635 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 636 ** information is written to disk in the same order as calls 637 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 638 ** after reboot following a crash or power loss, the only bytes in a 639 ** file that were written at the application level might have changed 640 ** and that adjacent bytes, even bytes within the same sector are 641 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 642 ** flag indicates that a file cannot be deleted when open. The 643 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 644 ** read-only media and cannot be changed even by processes with 645 ** elevated privileges. 646 ** 647 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 648 ** filesystem supports doing multiple write operations atomically when those 649 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 650 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 651 */ 652 #define SQLITE_IOCAP_ATOMIC 0x00000001 653 #define SQLITE_IOCAP_ATOMIC512 0x00000002 654 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 655 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 656 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 657 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 658 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 659 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 660 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 661 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 662 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 663 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 664 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 665 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 666 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 667 668 /* 669 ** CAPI3REF: File Locking Levels 670 ** 671 ** SQLite uses one of these integer values as the second 672 ** argument to calls it makes to the xLock() and xUnlock() methods 673 ** of an [sqlite3_io_methods] object. These values are ordered from 674 ** lest restrictive to most restrictive. 675 ** 676 ** The argument to xLock() is always SHARED or higher. The argument to 677 ** xUnlock is either SHARED or NONE. 678 */ 679 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 680 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 681 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 682 #define SQLITE_LOCK_PENDING 3 /* xLock() only */ 683 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 684 685 /* 686 ** CAPI3REF: Synchronization Type Flags 687 ** 688 ** When SQLite invokes the xSync() method of an 689 ** [sqlite3_io_methods] object it uses a combination of 690 ** these integer values as the second argument. 691 ** 692 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 693 ** sync operation only needs to flush data to mass storage. Inode 694 ** information need not be flushed. If the lower four bits of the flag 695 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 696 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 697 ** to use Mac OS X style fullsync instead of fsync(). 698 ** 699 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 700 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 701 ** settings. The [synchronous pragma] determines when calls to the 702 ** xSync VFS method occur and applies uniformly across all platforms. 703 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 704 ** energetic or rigorous or forceful the sync operations are and 705 ** only make a difference on Mac OSX for the default SQLite code. 706 ** (Third-party VFS implementations might also make the distinction 707 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 708 ** operating systems natively supported by SQLite, only Mac OSX 709 ** cares about the difference.) 710 */ 711 #define SQLITE_SYNC_NORMAL 0x00002 712 #define SQLITE_SYNC_FULL 0x00003 713 #define SQLITE_SYNC_DATAONLY 0x00010 714 715 /* 716 ** CAPI3REF: OS Interface Open File Handle 717 ** 718 ** An [sqlite3_file] object represents an open file in the 719 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 720 ** implementations will 721 ** want to subclass this object by appending additional fields 722 ** for their own use. The pMethods entry is a pointer to an 723 ** [sqlite3_io_methods] object that defines methods for performing 724 ** I/O operations on the open file. 725 */ 726 typedef struct sqlite3_file sqlite3_file; 727 struct sqlite3_file { 728 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 729 }; 730 731 /* 732 ** CAPI3REF: OS Interface File Virtual Methods Object 733 ** 734 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 735 ** [sqlite3_file] object (or, more commonly, a subclass of the 736 ** [sqlite3_file] object) with a pointer to an instance of this object. 737 ** This object defines the methods used to perform various operations 738 ** against the open file represented by the [sqlite3_file] object. 739 ** 740 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 741 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 742 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 743 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 744 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 745 ** to NULL. 746 ** 747 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 748 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 749 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 750 ** flag may be ORed in to indicate that only the data of the file 751 ** and not its inode needs to be synced. 752 ** 753 ** The integer values to xLock() and xUnlock() are one of 754 ** <ul> 755 ** <li> [SQLITE_LOCK_NONE], 756 ** <li> [SQLITE_LOCK_SHARED], 757 ** <li> [SQLITE_LOCK_RESERVED], 758 ** <li> [SQLITE_LOCK_PENDING], or 759 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 760 ** </ul> 761 ** xLock() upgrades the database file lock. In other words, xLock() moves the 762 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to 763 ** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 764 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the 765 ** requested lock, then the call to xLock() is a no-op. 766 ** xUnlock() downgrades the database file lock to either SHARED or NONE. 767 * If the lock is already at or below the requested lock state, then the call 768 ** to xUnlock() is a no-op. 769 ** The xCheckReservedLock() method checks whether any database connection, 770 ** either in this process or in some other process, is holding a RESERVED, 771 ** PENDING, or EXCLUSIVE lock on the file. It returns true 772 ** if such a lock exists and false otherwise. 773 ** 774 ** The xFileControl() method is a generic interface that allows custom 775 ** VFS implementations to directly control an open file using the 776 ** [sqlite3_file_control()] interface. The second "op" argument is an 777 ** integer opcode. The third argument is a generic pointer intended to 778 ** point to a structure that may contain arguments or space in which to 779 ** write return values. Potential uses for xFileControl() might be 780 ** functions to enable blocking locks with timeouts, to change the 781 ** locking strategy (for example to use dot-file locks), to inquire 782 ** about the status of a lock, or to break stale locks. The SQLite 783 ** core reserves all opcodes less than 100 for its own use. 784 ** A [file control opcodes | list of opcodes] less than 100 is available. 785 ** Applications that define a custom xFileControl method should use opcodes 786 ** greater than 100 to avoid conflicts. VFS implementations should 787 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 788 ** recognize. 789 ** 790 ** The xSectorSize() method returns the sector size of the 791 ** device that underlies the file. The sector size is the 792 ** minimum write that can be performed without disturbing 793 ** other bytes in the file. The xDeviceCharacteristics() 794 ** method returns a bit vector describing behaviors of the 795 ** underlying device: 796 ** 797 ** <ul> 798 ** <li> [SQLITE_IOCAP_ATOMIC] 799 ** <li> [SQLITE_IOCAP_ATOMIC512] 800 ** <li> [SQLITE_IOCAP_ATOMIC1K] 801 ** <li> [SQLITE_IOCAP_ATOMIC2K] 802 ** <li> [SQLITE_IOCAP_ATOMIC4K] 803 ** <li> [SQLITE_IOCAP_ATOMIC8K] 804 ** <li> [SQLITE_IOCAP_ATOMIC16K] 805 ** <li> [SQLITE_IOCAP_ATOMIC32K] 806 ** <li> [SQLITE_IOCAP_ATOMIC64K] 807 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 808 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 809 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 810 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 811 ** <li> [SQLITE_IOCAP_IMMUTABLE] 812 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 813 ** </ul> 814 ** 815 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 816 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 817 ** mean that writes of blocks that are nnn bytes in size and 818 ** are aligned to an address which is an integer multiple of 819 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 820 ** that when data is appended to a file, the data is appended 821 ** first then the size of the file is extended, never the other 822 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 823 ** information is written to disk in the same order as calls 824 ** to xWrite(). 825 ** 826 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 827 ** in the unread portions of the buffer with zeros. A VFS that 828 ** fails to zero-fill short reads might seem to work. However, 829 ** failure to zero-fill short reads will eventually lead to 830 ** database corruption. 831 */ 832 typedef struct sqlite3_io_methods sqlite3_io_methods; 833 struct sqlite3_io_methods { 834 int iVersion; 835 int (*xClose)(sqlite3_file*); 836 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 837 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 838 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 839 int (*xSync)(sqlite3_file*, int flags); 840 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 841 int (*xLock)(sqlite3_file*, int); 842 int (*xUnlock)(sqlite3_file*, int); 843 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 844 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 845 int (*xSectorSize)(sqlite3_file*); 846 int (*xDeviceCharacteristics)(sqlite3_file*); 847 /* Methods above are valid for version 1 */ 848 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 849 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 850 void (*xShmBarrier)(sqlite3_file*); 851 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 852 /* Methods above are valid for version 2 */ 853 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 854 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 855 /* Methods above are valid for version 3 */ 856 /* Additional methods may be added in future releases */ 857 }; 858 859 /* 860 ** CAPI3REF: Standard File Control Opcodes 861 ** KEYWORDS: {file control opcodes} {file control opcode} 862 ** 863 ** These integer constants are opcodes for the xFileControl method 864 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 865 ** interface. 866 ** 867 ** <ul> 868 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 869 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 870 ** opcode causes the xFileControl method to write the current state of 871 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 872 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 873 ** into an integer that the pArg argument points to. 874 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 875 ** 876 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 877 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 878 ** layer a hint of how large the database file will grow to be during the 879 ** current transaction. This hint is not guaranteed to be accurate but it 880 ** is often close. The underlying VFS might choose to preallocate database 881 ** file space based on this hint in order to help writes to the database 882 ** file run faster. 883 ** 884 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 885 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 886 ** implements [sqlite3_deserialize()] to set an upper bound on the size 887 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 888 ** If the integer pointed to is negative, then it is filled in with the 889 ** current limit. Otherwise the limit is set to the larger of the value 890 ** of the integer pointed to and the current database size. The integer 891 ** pointed to is set to the new limit. 892 ** 893 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 894 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 895 ** extends and truncates the database file in chunks of a size specified 896 ** by the user. The fourth argument to [sqlite3_file_control()] should 897 ** point to an integer (type int) containing the new chunk-size to use 898 ** for the nominated database. Allocating database file space in large 899 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 900 ** improve performance on some systems. 901 ** 902 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 903 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 904 ** to the [sqlite3_file] object associated with a particular database 905 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 906 ** 907 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 908 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 909 ** to the [sqlite3_file] object associated with the journal file (either 910 ** the [rollback journal] or the [write-ahead log]) for a particular database 911 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 912 ** 913 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 914 ** No longer in use. 915 ** 916 ** <li>[[SQLITE_FCNTL_SYNC]] 917 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 918 ** sent to the VFS immediately before the xSync method is invoked on a 919 ** database file descriptor. Or, if the xSync method is not invoked 920 ** because the user has configured SQLite with 921 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 922 ** of the xSync method. In most cases, the pointer argument passed with 923 ** this file-control is NULL. However, if the database file is being synced 924 ** as part of a multi-database commit, the argument points to a nul-terminated 925 ** string containing the transactions super-journal file name. VFSes that 926 ** do not need this signal should silently ignore this opcode. Applications 927 ** should not call [sqlite3_file_control()] with this opcode as doing so may 928 ** disrupt the operation of the specialized VFSes that do require it. 929 ** 930 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 931 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 932 ** and sent to the VFS after a transaction has been committed immediately 933 ** but before the database is unlocked. VFSes that do not need this signal 934 ** should silently ignore this opcode. Applications should not call 935 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 936 ** operation of the specialized VFSes that do require it. 937 ** 938 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 939 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 940 ** retry counts and intervals for certain disk I/O operations for the 941 ** windows [VFS] in order to provide robustness in the presence of 942 ** anti-virus programs. By default, the windows VFS will retry file read, 943 ** file write, and file delete operations up to 10 times, with a delay 944 ** of 25 milliseconds before the first retry and with the delay increasing 945 ** by an additional 25 milliseconds with each subsequent retry. This 946 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 947 ** to be adjusted. The values are changed for all database connections 948 ** within the same process. The argument is a pointer to an array of two 949 ** integers where the first integer is the new retry count and the second 950 ** integer is the delay. If either integer is negative, then the setting 951 ** is not changed but instead the prior value of that setting is written 952 ** into the array entry, allowing the current retry settings to be 953 ** interrogated. The zDbName parameter is ignored. 954 ** 955 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 956 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 957 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 958 ** write ahead log ([WAL file]) and shared memory 959 ** files used for transaction control 960 ** are automatically deleted when the latest connection to the database 961 ** closes. Setting persistent WAL mode causes those files to persist after 962 ** close. Persisting the files is useful when other processes that do not 963 ** have write permission on the directory containing the database file want 964 ** to read the database file, as the WAL and shared memory files must exist 965 ** in order for the database to be readable. The fourth parameter to 966 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 967 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 968 ** WAL mode. If the integer is -1, then it is overwritten with the current 969 ** WAL persistence setting. 970 ** 971 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 972 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 973 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 974 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 975 ** xDeviceCharacteristics methods. The fourth parameter to 976 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 977 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 978 ** mode. If the integer is -1, then it is overwritten with the current 979 ** zero-damage mode setting. 980 ** 981 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 982 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 983 ** a write transaction to indicate that, unless it is rolled back for some 984 ** reason, the entire database file will be overwritten by the current 985 ** transaction. This is used by VACUUM operations. 986 ** 987 ** <li>[[SQLITE_FCNTL_VFSNAME]] 988 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 989 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 990 ** final bottom-level VFS are written into memory obtained from 991 ** [sqlite3_malloc()] and the result is stored in the char* variable 992 ** that the fourth parameter of [sqlite3_file_control()] points to. 993 ** The caller is responsible for freeing the memory when done. As with 994 ** all file-control actions, there is no guarantee that this will actually 995 ** do anything. Callers should initialize the char* variable to a NULL 996 ** pointer in case this file-control is not implemented. This file-control 997 ** is intended for diagnostic use only. 998 ** 999 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1000 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1001 ** [VFSes] currently in use. ^(The argument X in 1002 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1003 ** of type "[sqlite3_vfs] **". This opcodes will set *X 1004 ** to a pointer to the top-level VFS.)^ 1005 ** ^When there are multiple VFS shims in the stack, this opcode finds the 1006 ** upper-most shim only. 1007 ** 1008 ** <li>[[SQLITE_FCNTL_PRAGMA]] 1009 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1010 ** file control is sent to the open [sqlite3_file] object corresponding 1011 ** to the database file to which the pragma statement refers. ^The argument 1012 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1013 ** pointers to strings (char**) in which the second element of the array 1014 ** is the name of the pragma and the third element is the argument to the 1015 ** pragma or NULL if the pragma has no argument. ^The handler for an 1016 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1017 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1018 ** or the equivalent and that string will become the result of the pragma or 1019 ** the error message if the pragma fails. ^If the 1020 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1021 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1022 ** file control returns [SQLITE_OK], then the parser assumes that the 1023 ** VFS has handled the PRAGMA itself and the parser generates a no-op 1024 ** prepared statement if result string is NULL, or that returns a copy 1025 ** of the result string if the string is non-NULL. 1026 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1027 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1028 ** that the VFS encountered an error while handling the [PRAGMA] and the 1029 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1030 ** file control occurs at the beginning of pragma statement analysis and so 1031 ** it is able to override built-in [PRAGMA] statements. 1032 ** 1033 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1034 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 1035 ** file-control may be invoked by SQLite on the database file handle 1036 ** shortly after it is opened in order to provide a custom VFS with access 1037 ** to the connection's busy-handler callback. The argument is of type (void**) 1038 ** - an array of two (void *) values. The first (void *) actually points 1039 ** to a function of type (int (*)(void *)). In order to invoke the connection's 1040 ** busy-handler, this function should be invoked with the second (void *) in 1041 ** the array as the only argument. If it returns non-zero, then the operation 1042 ** should be retried. If it returns zero, the custom VFS should abandon the 1043 ** current operation. 1044 ** 1045 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1046 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1047 ** to have SQLite generate a 1048 ** temporary filename using the same algorithm that is followed to generate 1049 ** temporary filenames for TEMP tables and other internal uses. The 1050 ** argument should be a char** which will be filled with the filename 1051 ** written into memory obtained from [sqlite3_malloc()]. The caller should 1052 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 1053 ** 1054 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1055 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1056 ** maximum number of bytes that will be used for memory-mapped I/O. 1057 ** The argument is a pointer to a value of type sqlite3_int64 that 1058 ** is an advisory maximum number of bytes in the file to memory map. The 1059 ** pointer is overwritten with the old value. The limit is not changed if 1060 ** the value originally pointed to is negative, and so the current limit 1061 ** can be queried by passing in a pointer to a negative number. This 1062 ** file-control is used internally to implement [PRAGMA mmap_size]. 1063 ** 1064 ** <li>[[SQLITE_FCNTL_TRACE]] 1065 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1066 ** to the VFS about what the higher layers of the SQLite stack are doing. 1067 ** This file control is used by some VFS activity tracing [shims]. 1068 ** The argument is a zero-terminated string. Higher layers in the 1069 ** SQLite stack may generate instances of this file control if 1070 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1071 ** 1072 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1073 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1074 ** pointer to an integer and it writes a boolean into that integer depending 1075 ** on whether or not the file has been renamed, moved, or deleted since it 1076 ** was first opened. 1077 ** 1078 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1079 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1080 ** underlying native file handle associated with a file handle. This file 1081 ** control interprets its argument as a pointer to a native file handle and 1082 ** writes the resulting value there. 1083 ** 1084 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1085 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1086 ** opcode causes the xFileControl method to swap the file handle with the one 1087 ** pointed to by the pArg argument. This capability is used during testing 1088 ** and only needs to be supported when SQLITE_TEST is defined. 1089 ** 1090 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1091 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1092 ** be advantageous to block on the next WAL lock if the lock is not immediately 1093 ** available. The WAL subsystem issues this signal during rare 1094 ** circumstances in order to fix a problem with priority inversion. 1095 ** Applications should <em>not</em> use this file-control. 1096 ** 1097 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1098 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1099 ** VFS should return SQLITE_NOTFOUND for this opcode. 1100 ** 1101 ** <li>[[SQLITE_FCNTL_RBU]] 1102 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1103 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1104 ** this opcode. 1105 ** 1106 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1107 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1108 ** the file descriptor is placed in "batch write mode", which 1109 ** means all subsequent write operations will be deferred and done 1110 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1111 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1112 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1113 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1114 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1115 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1116 ** except for calls to the xWrite method and the xFileControl method 1117 ** with [SQLITE_FCNTL_SIZE_HINT]. 1118 ** 1119 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1120 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1121 ** operations since the previous successful call to 1122 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1123 ** This file control returns [SQLITE_OK] if and only if the writes were 1124 ** all performed successfully and have been committed to persistent storage. 1125 ** ^Regardless of whether or not it is successful, this file control takes 1126 ** the file descriptor out of batch write mode so that all subsequent 1127 ** write operations are independent. 1128 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1129 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1130 ** 1131 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1132 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1133 ** operations since the previous successful call to 1134 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1135 ** ^This file control takes the file descriptor out of batch write mode 1136 ** so that all subsequent write operations are independent. 1137 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1138 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1139 ** 1140 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1141 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1142 ** to block for up to M milliseconds before failing when attempting to 1143 ** obtain a file lock using the xLock or xShmLock methods of the VFS. 1144 ** The parameter is a pointer to a 32-bit signed integer that contains 1145 ** the value that M is to be set to. Before returning, the 32-bit signed 1146 ** integer is overwritten with the previous value of M. 1147 ** 1148 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1149 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1150 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1151 ** The "data version" for the pager is written into the pointer. The 1152 ** "data version" changes whenever any change occurs to the corresponding 1153 ** database file, either through SQL statements on the same database 1154 ** connection or through transactions committed by separate database 1155 ** connections possibly in other processes. The [sqlite3_total_changes()] 1156 ** interface can be used to find if any database on the connection has changed, 1157 ** but that interface responds to changes on TEMP as well as MAIN and does 1158 ** not provide a mechanism to detect changes to MAIN only. Also, the 1159 ** [sqlite3_total_changes()] interface responds to internal changes only and 1160 ** omits changes made by other database connections. The 1161 ** [PRAGMA data_version] command provides a mechanism to detect changes to 1162 ** a single attached database that occur due to other database connections, 1163 ** but omits changes implemented by the database connection on which it is 1164 ** called. This file control is the only mechanism to detect changes that 1165 ** happen either internally or externally and that are associated with 1166 ** a particular attached database. 1167 ** 1168 ** <li>[[SQLITE_FCNTL_CKPT_START]] 1169 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1170 ** in wal mode before the client starts to copy pages from the wal 1171 ** file to the database file. 1172 ** 1173 ** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1174 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1175 ** in wal mode after the client has finished copying pages from the wal 1176 ** file to the database file, but before the *-shm file is updated to 1177 ** record the fact that the pages have been checkpointed. 1178 ** </ul> 1179 ** 1180 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1181 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1182 ** whether or not there is a database client in another process with a wal-mode 1183 ** transaction open on the database or not. It is only available on unix.The 1184 ** (void*) argument passed with this file-control should be a pointer to a 1185 ** value of type (int). The integer value is set to 1 if the database is a wal 1186 ** mode database and there exists at least one client in another process that 1187 ** currently has an SQL transaction open on the database. It is set to 0 if 1188 ** the database is not a wal-mode db, or if there is no such connection in any 1189 ** other process. This opcode cannot be used to detect transactions opened 1190 ** by clients within the current process, only within other processes. 1191 ** </ul> 1192 ** 1193 ** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1194 ** Used by the cksmvfs VFS module only. 1195 ** 1196 ** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1197 ** If there is currently no transaction open on the database, and the 1198 ** database is not a temp db, then this file-control purges the contents 1199 ** of the in-memory page cache. If there is an open transaction, or if 1200 ** the db is a temp-db, it is a no-op, not an error. 1201 ** </ul> 1202 */ 1203 #define SQLITE_FCNTL_LOCKSTATE 1 1204 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1205 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1206 #define SQLITE_FCNTL_LAST_ERRNO 4 1207 #define SQLITE_FCNTL_SIZE_HINT 5 1208 #define SQLITE_FCNTL_CHUNK_SIZE 6 1209 #define SQLITE_FCNTL_FILE_POINTER 7 1210 #define SQLITE_FCNTL_SYNC_OMITTED 8 1211 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1212 #define SQLITE_FCNTL_PERSIST_WAL 10 1213 #define SQLITE_FCNTL_OVERWRITE 11 1214 #define SQLITE_FCNTL_VFSNAME 12 1215 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1216 #define SQLITE_FCNTL_PRAGMA 14 1217 #define SQLITE_FCNTL_BUSYHANDLER 15 1218 #define SQLITE_FCNTL_TEMPFILENAME 16 1219 #define SQLITE_FCNTL_MMAP_SIZE 18 1220 #define SQLITE_FCNTL_TRACE 19 1221 #define SQLITE_FCNTL_HAS_MOVED 20 1222 #define SQLITE_FCNTL_SYNC 21 1223 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1224 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1225 #define SQLITE_FCNTL_WAL_BLOCK 24 1226 #define SQLITE_FCNTL_ZIPVFS 25 1227 #define SQLITE_FCNTL_RBU 26 1228 #define SQLITE_FCNTL_VFS_POINTER 27 1229 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1230 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1231 #define SQLITE_FCNTL_PDB 30 1232 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1233 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1234 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1235 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1236 #define SQLITE_FCNTL_DATA_VERSION 35 1237 #define SQLITE_FCNTL_SIZE_LIMIT 36 1238 #define SQLITE_FCNTL_CKPT_DONE 37 1239 #define SQLITE_FCNTL_RESERVE_BYTES 38 1240 #define SQLITE_FCNTL_CKPT_START 39 1241 #define SQLITE_FCNTL_EXTERNAL_READER 40 1242 #define SQLITE_FCNTL_CKSM_FILE 41 1243 #define SQLITE_FCNTL_RESET_CACHE 42 1244 1245 /* deprecated names */ 1246 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1247 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1248 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1249 1250 1251 /* 1252 ** CAPI3REF: Mutex Handle 1253 ** 1254 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1255 ** abstract type for a mutex object. The SQLite core never looks 1256 ** at the internal representation of an [sqlite3_mutex]. It only 1257 ** deals with pointers to the [sqlite3_mutex] object. 1258 ** 1259 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1260 */ 1261 typedef struct sqlite3_mutex sqlite3_mutex; 1262 1263 /* 1264 ** CAPI3REF: Loadable Extension Thunk 1265 ** 1266 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1267 ** the third parameter to entry points of [loadable extensions]. This 1268 ** structure must be typedefed in order to work around compiler warnings 1269 ** on some platforms. 1270 */ 1271 typedef struct sqlite3_api_routines sqlite3_api_routines; 1272 1273 /* 1274 ** CAPI3REF: File Name 1275 ** 1276 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1277 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1278 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1279 ** may also be passed to special APIs such as: 1280 ** 1281 ** <ul> 1282 ** <li> sqlite3_filename_database() 1283 ** <li> sqlite3_filename_journal() 1284 ** <li> sqlite3_filename_wal() 1285 ** <li> sqlite3_uri_parameter() 1286 ** <li> sqlite3_uri_boolean() 1287 ** <li> sqlite3_uri_int64() 1288 ** <li> sqlite3_uri_key() 1289 ** </ul> 1290 */ 1291 typedef const char *sqlite3_filename; 1292 1293 /* 1294 ** CAPI3REF: OS Interface Object 1295 ** 1296 ** An instance of the sqlite3_vfs object defines the interface between 1297 ** the SQLite core and the underlying operating system. The "vfs" 1298 ** in the name of the object stands for "virtual file system". See 1299 ** the [VFS | VFS documentation] for further information. 1300 ** 1301 ** The VFS interface is sometimes extended by adding new methods onto 1302 ** the end. Each time such an extension occurs, the iVersion field 1303 ** is incremented. The iVersion value started out as 1 in 1304 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1305 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1306 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1307 ** may be appended to the sqlite3_vfs object and the iVersion value 1308 ** may increase again in future versions of SQLite. 1309 ** Note that due to an oversight, the structure 1310 ** of the sqlite3_vfs object changed in the transition from 1311 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1312 ** and yet the iVersion field was not increased. 1313 ** 1314 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1315 ** structure used by this VFS. mxPathname is the maximum length of 1316 ** a pathname in this VFS. 1317 ** 1318 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1319 ** the pNext pointer. The [sqlite3_vfs_register()] 1320 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1321 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1322 ** searches the list. Neither the application code nor the VFS 1323 ** implementation should use the pNext pointer. 1324 ** 1325 ** The pNext field is the only field in the sqlite3_vfs 1326 ** structure that SQLite will ever modify. SQLite will only access 1327 ** or modify this field while holding a particular static mutex. 1328 ** The application should never modify anything within the sqlite3_vfs 1329 ** object once the object has been registered. 1330 ** 1331 ** The zName field holds the name of the VFS module. The name must 1332 ** be unique across all VFS modules. 1333 ** 1334 ** [[sqlite3_vfs.xOpen]] 1335 ** ^SQLite guarantees that the zFilename parameter to xOpen 1336 ** is either a NULL pointer or string obtained 1337 ** from xFullPathname() with an optional suffix added. 1338 ** ^If a suffix is added to the zFilename parameter, it will 1339 ** consist of a single "-" character followed by no more than 1340 ** 11 alphanumeric and/or "-" characters. 1341 ** ^SQLite further guarantees that 1342 ** the string will be valid and unchanged until xClose() is 1343 ** called. Because of the previous sentence, 1344 ** the [sqlite3_file] can safely store a pointer to the 1345 ** filename if it needs to remember the filename for some reason. 1346 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1347 ** must invent its own temporary name for the file. ^Whenever the 1348 ** xFilename parameter is NULL it will also be the case that the 1349 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1350 ** 1351 ** The flags argument to xOpen() includes all bits set in 1352 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1353 ** or [sqlite3_open16()] is used, then flags includes at least 1354 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1355 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1356 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1357 ** 1358 ** ^(SQLite will also add one of the following flags to the xOpen() 1359 ** call, depending on the object being opened: 1360 ** 1361 ** <ul> 1362 ** <li> [SQLITE_OPEN_MAIN_DB] 1363 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1364 ** <li> [SQLITE_OPEN_TEMP_DB] 1365 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1366 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1367 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1368 ** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1369 ** <li> [SQLITE_OPEN_WAL] 1370 ** </ul>)^ 1371 ** 1372 ** The file I/O implementation can use the object type flags to 1373 ** change the way it deals with files. For example, an application 1374 ** that does not care about crash recovery or rollback might make 1375 ** the open of a journal file a no-op. Writes to this journal would 1376 ** also be no-ops, and any attempt to read the journal would return 1377 ** SQLITE_IOERR. Or the implementation might recognize that a database 1378 ** file will be doing page-aligned sector reads and writes in a random 1379 ** order and set up its I/O subsystem accordingly. 1380 ** 1381 ** SQLite might also add one of the following flags to the xOpen method: 1382 ** 1383 ** <ul> 1384 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1385 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1386 ** </ul> 1387 ** 1388 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1389 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1390 ** will be set for TEMP databases and their journals, transient 1391 ** databases, and subjournals. 1392 ** 1393 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1394 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1395 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1396 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1397 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1398 ** be created, and that it is an error if it already exists. 1399 ** It is <i>not</i> used to indicate the file should be opened 1400 ** for exclusive access. 1401 ** 1402 ** ^At least szOsFile bytes of memory are allocated by SQLite 1403 ** to hold the [sqlite3_file] structure passed as the third 1404 ** argument to xOpen. The xOpen method does not have to 1405 ** allocate the structure; it should just fill it in. Note that 1406 ** the xOpen method must set the sqlite3_file.pMethods to either 1407 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1408 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1409 ** element will be valid after xOpen returns regardless of the success 1410 ** or failure of the xOpen call. 1411 ** 1412 ** [[sqlite3_vfs.xAccess]] 1413 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1414 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1415 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1416 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1417 ** flag is never actually used and is not implemented in the built-in 1418 ** VFSes of SQLite. The file is named by the second argument and can be a 1419 ** directory. The xAccess method returns [SQLITE_OK] on success or some 1420 ** non-zero error code if there is an I/O error or if the name of 1421 ** the file given in the second argument is illegal. If SQLITE_OK 1422 ** is returned, then non-zero or zero is written into *pResOut to indicate 1423 ** whether or not the file is accessible. 1424 ** 1425 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1426 ** output buffer xFullPathname. The exact size of the output buffer 1427 ** is also passed as a parameter to both methods. If the output buffer 1428 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1429 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1430 ** to prevent this by setting mxPathname to a sufficiently large value. 1431 ** 1432 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1433 ** interfaces are not strictly a part of the filesystem, but they are 1434 ** included in the VFS structure for completeness. 1435 ** The xRandomness() function attempts to return nBytes bytes 1436 ** of good-quality randomness into zOut. The return value is 1437 ** the actual number of bytes of randomness obtained. 1438 ** The xSleep() method causes the calling thread to sleep for at 1439 ** least the number of microseconds given. ^The xCurrentTime() 1440 ** method returns a Julian Day Number for the current date and time as 1441 ** a floating point value. 1442 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1443 ** Day Number multiplied by 86400000 (the number of milliseconds in 1444 ** a 24-hour day). 1445 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1446 ** date and time if that method is available (if iVersion is 2 or 1447 ** greater and the function pointer is not NULL) and will fall back 1448 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1449 ** 1450 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1451 ** are not used by the SQLite core. These optional interfaces are provided 1452 ** by some VFSes to facilitate testing of the VFS code. By overriding 1453 ** system calls with functions under its control, a test program can 1454 ** simulate faults and error conditions that would otherwise be difficult 1455 ** or impossible to induce. The set of system calls that can be overridden 1456 ** varies from one VFS to another, and from one version of the same VFS to the 1457 ** next. Applications that use these interfaces must be prepared for any 1458 ** or all of these interfaces to be NULL or for their behavior to change 1459 ** from one release to the next. Applications must not attempt to access 1460 ** any of these methods if the iVersion of the VFS is less than 3. 1461 */ 1462 typedef struct sqlite3_vfs sqlite3_vfs; 1463 typedef void (*sqlite3_syscall_ptr)(void); 1464 struct sqlite3_vfs { 1465 int iVersion; /* Structure version number (currently 3) */ 1466 int szOsFile; /* Size of subclassed sqlite3_file */ 1467 int mxPathname; /* Maximum file pathname length */ 1468 sqlite3_vfs *pNext; /* Next registered VFS */ 1469 const char *zName; /* Name of this virtual file system */ 1470 void *pAppData; /* Pointer to application-specific data */ 1471 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1472 int flags, int *pOutFlags); 1473 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1474 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1475 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1476 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1477 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1478 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1479 void (*xDlClose)(sqlite3_vfs*, void*); 1480 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1481 int (*xSleep)(sqlite3_vfs*, int microseconds); 1482 int (*xCurrentTime)(sqlite3_vfs*, double*); 1483 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1484 /* 1485 ** The methods above are in version 1 of the sqlite_vfs object 1486 ** definition. Those that follow are added in version 2 or later 1487 */ 1488 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1489 /* 1490 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1491 ** Those below are for version 3 and greater. 1492 */ 1493 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1494 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1495 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1496 /* 1497 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1498 ** New fields may be appended in future versions. The iVersion 1499 ** value will increment whenever this happens. 1500 */ 1501 }; 1502 1503 /* 1504 ** CAPI3REF: Flags for the xAccess VFS method 1505 ** 1506 ** These integer constants can be used as the third parameter to 1507 ** the xAccess method of an [sqlite3_vfs] object. They determine 1508 ** what kind of permissions the xAccess method is looking for. 1509 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1510 ** simply checks whether the file exists. 1511 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1512 ** checks whether the named directory is both readable and writable 1513 ** (in other words, if files can be added, removed, and renamed within 1514 ** the directory). 1515 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1516 ** [temp_store_directory pragma], though this could change in a future 1517 ** release of SQLite. 1518 ** With SQLITE_ACCESS_READ, the xAccess method 1519 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1520 ** currently unused, though it might be used in a future release of 1521 ** SQLite. 1522 */ 1523 #define SQLITE_ACCESS_EXISTS 0 1524 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1525 #define SQLITE_ACCESS_READ 2 /* Unused */ 1526 1527 /* 1528 ** CAPI3REF: Flags for the xShmLock VFS method 1529 ** 1530 ** These integer constants define the various locking operations 1531 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1532 ** following are the only legal combinations of flags to the 1533 ** xShmLock method: 1534 ** 1535 ** <ul> 1536 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1537 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1538 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1539 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1540 ** </ul> 1541 ** 1542 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1543 ** was given on the corresponding lock. 1544 ** 1545 ** The xShmLock method can transition between unlocked and SHARED or 1546 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1547 ** and EXCLUSIVE. 1548 */ 1549 #define SQLITE_SHM_UNLOCK 1 1550 #define SQLITE_SHM_LOCK 2 1551 #define SQLITE_SHM_SHARED 4 1552 #define SQLITE_SHM_EXCLUSIVE 8 1553 1554 /* 1555 ** CAPI3REF: Maximum xShmLock index 1556 ** 1557 ** The xShmLock method on [sqlite3_io_methods] may use values 1558 ** between 0 and this upper bound as its "offset" argument. 1559 ** The SQLite core will never attempt to acquire or release a 1560 ** lock outside of this range 1561 */ 1562 #define SQLITE_SHM_NLOCK 8 1563 1564 1565 /* 1566 ** CAPI3REF: Initialize The SQLite Library 1567 ** 1568 ** ^The sqlite3_initialize() routine initializes the 1569 ** SQLite library. ^The sqlite3_shutdown() routine 1570 ** deallocates any resources that were allocated by sqlite3_initialize(). 1571 ** These routines are designed to aid in process initialization and 1572 ** shutdown on embedded systems. Workstation applications using 1573 ** SQLite normally do not need to invoke either of these routines. 1574 ** 1575 ** A call to sqlite3_initialize() is an "effective" call if it is 1576 ** the first time sqlite3_initialize() is invoked during the lifetime of 1577 ** the process, or if it is the first time sqlite3_initialize() is invoked 1578 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1579 ** of sqlite3_initialize() does any initialization. All other calls 1580 ** are harmless no-ops.)^ 1581 ** 1582 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1583 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1584 ** an effective call to sqlite3_shutdown() does any deinitialization. 1585 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1586 ** 1587 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1588 ** is not. The sqlite3_shutdown() interface must only be called from a 1589 ** single thread. All open [database connections] must be closed and all 1590 ** other SQLite resources must be deallocated prior to invoking 1591 ** sqlite3_shutdown(). 1592 ** 1593 ** Among other things, ^sqlite3_initialize() will invoke 1594 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1595 ** will invoke sqlite3_os_end(). 1596 ** 1597 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1598 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1599 ** the library (perhaps it is unable to allocate a needed resource such 1600 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1601 ** 1602 ** ^The sqlite3_initialize() routine is called internally by many other 1603 ** SQLite interfaces so that an application usually does not need to 1604 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1605 ** calls sqlite3_initialize() so the SQLite library will be automatically 1606 ** initialized when [sqlite3_open()] is called if it has not be initialized 1607 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1608 ** compile-time option, then the automatic calls to sqlite3_initialize() 1609 ** are omitted and the application must call sqlite3_initialize() directly 1610 ** prior to using any other SQLite interface. For maximum portability, 1611 ** it is recommended that applications always invoke sqlite3_initialize() 1612 ** directly prior to using any other SQLite interface. Future releases 1613 ** of SQLite may require this. In other words, the behavior exhibited 1614 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1615 ** default behavior in some future release of SQLite. 1616 ** 1617 ** The sqlite3_os_init() routine does operating-system specific 1618 ** initialization of the SQLite library. The sqlite3_os_end() 1619 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1620 ** performed by these routines include allocation or deallocation 1621 ** of static resources, initialization of global variables, 1622 ** setting up a default [sqlite3_vfs] module, or setting up 1623 ** a default configuration using [sqlite3_config()]. 1624 ** 1625 ** The application should never invoke either sqlite3_os_init() 1626 ** or sqlite3_os_end() directly. The application should only invoke 1627 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1628 ** interface is called automatically by sqlite3_initialize() and 1629 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1630 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1631 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1632 ** When [custom builds | built for other platforms] 1633 ** (using the [SQLITE_OS_OTHER=1] compile-time 1634 ** option) the application must supply a suitable implementation for 1635 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1636 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1637 ** must return [SQLITE_OK] on success and some other [error code] upon 1638 ** failure. 1639 */ 1640 SQLITE_API int sqlite3_initialize(void); 1641 SQLITE_API int sqlite3_shutdown(void); 1642 SQLITE_API int sqlite3_os_init(void); 1643 SQLITE_API int sqlite3_os_end(void); 1644 1645 /* 1646 ** CAPI3REF: Configuring The SQLite Library 1647 ** 1648 ** The sqlite3_config() interface is used to make global configuration 1649 ** changes to SQLite in order to tune SQLite to the specific needs of 1650 ** the application. The default configuration is recommended for most 1651 ** applications and so this routine is usually not necessary. It is 1652 ** provided to support rare applications with unusual needs. 1653 ** 1654 ** <b>The sqlite3_config() interface is not threadsafe. The application 1655 ** must ensure that no other SQLite interfaces are invoked by other 1656 ** threads while sqlite3_config() is running.</b> 1657 ** 1658 ** The sqlite3_config() interface 1659 ** may only be invoked prior to library initialization using 1660 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1661 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1662 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1663 ** Note, however, that ^sqlite3_config() can be called as part of the 1664 ** implementation of an application-defined [sqlite3_os_init()]. 1665 ** 1666 ** The first argument to sqlite3_config() is an integer 1667 ** [configuration option] that determines 1668 ** what property of SQLite is to be configured. Subsequent arguments 1669 ** vary depending on the [configuration option] 1670 ** in the first argument. 1671 ** 1672 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1673 ** ^If the option is unknown or SQLite is unable to set the option 1674 ** then this routine returns a non-zero [error code]. 1675 */ 1676 SQLITE_API int sqlite3_config(int, ...); 1677 1678 /* 1679 ** CAPI3REF: Configure database connections 1680 ** METHOD: sqlite3 1681 ** 1682 ** The sqlite3_db_config() interface is used to make configuration 1683 ** changes to a [database connection]. The interface is similar to 1684 ** [sqlite3_config()] except that the changes apply to a single 1685 ** [database connection] (specified in the first argument). 1686 ** 1687 ** The second argument to sqlite3_db_config(D,V,...) is the 1688 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1689 ** that indicates what aspect of the [database connection] is being configured. 1690 ** Subsequent arguments vary depending on the configuration verb. 1691 ** 1692 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1693 ** the call is considered successful. 1694 */ 1695 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1696 1697 /* 1698 ** CAPI3REF: Memory Allocation Routines 1699 ** 1700 ** An instance of this object defines the interface between SQLite 1701 ** and low-level memory allocation routines. 1702 ** 1703 ** This object is used in only one place in the SQLite interface. 1704 ** A pointer to an instance of this object is the argument to 1705 ** [sqlite3_config()] when the configuration option is 1706 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1707 ** By creating an instance of this object 1708 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1709 ** during configuration, an application can specify an alternative 1710 ** memory allocation subsystem for SQLite to use for all of its 1711 ** dynamic memory needs. 1712 ** 1713 ** Note that SQLite comes with several [built-in memory allocators] 1714 ** that are perfectly adequate for the overwhelming majority of applications 1715 ** and that this object is only useful to a tiny minority of applications 1716 ** with specialized memory allocation requirements. This object is 1717 ** also used during testing of SQLite in order to specify an alternative 1718 ** memory allocator that simulates memory out-of-memory conditions in 1719 ** order to verify that SQLite recovers gracefully from such 1720 ** conditions. 1721 ** 1722 ** The xMalloc, xRealloc, and xFree methods must work like the 1723 ** malloc(), realloc() and free() functions from the standard C library. 1724 ** ^SQLite guarantees that the second argument to 1725 ** xRealloc is always a value returned by a prior call to xRoundup. 1726 ** 1727 ** xSize should return the allocated size of a memory allocation 1728 ** previously obtained from xMalloc or xRealloc. The allocated size 1729 ** is always at least as big as the requested size but may be larger. 1730 ** 1731 ** The xRoundup method returns what would be the allocated size of 1732 ** a memory allocation given a particular requested size. Most memory 1733 ** allocators round up memory allocations at least to the next multiple 1734 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1735 ** Every memory allocation request coming in through [sqlite3_malloc()] 1736 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1737 ** that causes the corresponding memory allocation to fail. 1738 ** 1739 ** The xInit method initializes the memory allocator. For example, 1740 ** it might allocate any required mutexes or initialize internal data 1741 ** structures. The xShutdown method is invoked (indirectly) by 1742 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1743 ** by xInit. The pAppData pointer is used as the only parameter to 1744 ** xInit and xShutdown. 1745 ** 1746 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1747 ** the xInit method, so the xInit method need not be threadsafe. The 1748 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1749 ** not need to be threadsafe either. For all other methods, SQLite 1750 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1751 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1752 ** it is by default) and so the methods are automatically serialized. 1753 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1754 ** methods must be threadsafe or else make their own arrangements for 1755 ** serialization. 1756 ** 1757 ** SQLite will never invoke xInit() more than once without an intervening 1758 ** call to xShutdown(). 1759 */ 1760 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1761 struct sqlite3_mem_methods { 1762 void *(*xMalloc)(int); /* Memory allocation function */ 1763 void (*xFree)(void*); /* Free a prior allocation */ 1764 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1765 int (*xSize)(void*); /* Return the size of an allocation */ 1766 int (*xRoundup)(int); /* Round up request size to allocation size */ 1767 int (*xInit)(void*); /* Initialize the memory allocator */ 1768 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1769 void *pAppData; /* Argument to xInit() and xShutdown() */ 1770 }; 1771 1772 /* 1773 ** CAPI3REF: Configuration Options 1774 ** KEYWORDS: {configuration option} 1775 ** 1776 ** These constants are the available integer configuration options that 1777 ** can be passed as the first argument to the [sqlite3_config()] interface. 1778 ** 1779 ** New configuration options may be added in future releases of SQLite. 1780 ** Existing configuration options might be discontinued. Applications 1781 ** should check the return code from [sqlite3_config()] to make sure that 1782 ** the call worked. The [sqlite3_config()] interface will return a 1783 ** non-zero [error code] if a discontinued or unsupported configuration option 1784 ** is invoked. 1785 ** 1786 ** <dl> 1787 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1788 ** <dd>There are no arguments to this option. ^This option sets the 1789 ** [threading mode] to Single-thread. In other words, it disables 1790 ** all mutexing and puts SQLite into a mode where it can only be used 1791 ** by a single thread. ^If SQLite is compiled with 1792 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1793 ** it is not possible to change the [threading mode] from its default 1794 ** value of Single-thread and so [sqlite3_config()] will return 1795 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1796 ** configuration option.</dd> 1797 ** 1798 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1799 ** <dd>There are no arguments to this option. ^This option sets the 1800 ** [threading mode] to Multi-thread. In other words, it disables 1801 ** mutexing on [database connection] and [prepared statement] objects. 1802 ** The application is responsible for serializing access to 1803 ** [database connections] and [prepared statements]. But other mutexes 1804 ** are enabled so that SQLite will be safe to use in a multi-threaded 1805 ** environment as long as no two threads attempt to use the same 1806 ** [database connection] at the same time. ^If SQLite is compiled with 1807 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1808 ** it is not possible to set the Multi-thread [threading mode] and 1809 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1810 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1811 ** 1812 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1813 ** <dd>There are no arguments to this option. ^This option sets the 1814 ** [threading mode] to Serialized. In other words, this option enables 1815 ** all mutexes including the recursive 1816 ** mutexes on [database connection] and [prepared statement] objects. 1817 ** In this mode (which is the default when SQLite is compiled with 1818 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1819 ** to [database connections] and [prepared statements] so that the 1820 ** application is free to use the same [database connection] or the 1821 ** same [prepared statement] in different threads at the same time. 1822 ** ^If SQLite is compiled with 1823 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1824 ** it is not possible to set the Serialized [threading mode] and 1825 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1826 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1827 ** 1828 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1829 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1830 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1831 ** The argument specifies 1832 ** alternative low-level memory allocation routines to be used in place of 1833 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1834 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1835 ** before the [sqlite3_config()] call returns.</dd> 1836 ** 1837 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1838 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1839 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1840 ** The [sqlite3_mem_methods] 1841 ** structure is filled with the currently defined memory allocation routines.)^ 1842 ** This option can be used to overload the default memory allocation 1843 ** routines with a wrapper that simulations memory allocation failure or 1844 ** tracks memory usage, for example. </dd> 1845 ** 1846 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1847 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1848 ** type int, interpreted as a boolean, which if true provides a hint to 1849 ** SQLite that it should avoid large memory allocations if possible. 1850 ** SQLite will run faster if it is free to make large memory allocations, 1851 ** but some application might prefer to run slower in exchange for 1852 ** guarantees about memory fragmentation that are possible if large 1853 ** allocations are avoided. This hint is normally off. 1854 ** </dd> 1855 ** 1856 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1857 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1858 ** interpreted as a boolean, which enables or disables the collection of 1859 ** memory allocation statistics. ^(When memory allocation statistics are 1860 ** disabled, the following SQLite interfaces become non-operational: 1861 ** <ul> 1862 ** <li> [sqlite3_hard_heap_limit64()] 1863 ** <li> [sqlite3_memory_used()] 1864 ** <li> [sqlite3_memory_highwater()] 1865 ** <li> [sqlite3_soft_heap_limit64()] 1866 ** <li> [sqlite3_status64()] 1867 ** </ul>)^ 1868 ** ^Memory allocation statistics are enabled by default unless SQLite is 1869 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1870 ** allocation statistics are disabled by default. 1871 ** </dd> 1872 ** 1873 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1874 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1875 ** </dd> 1876 ** 1877 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1878 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1879 ** that SQLite can use for the database page cache with the default page 1880 ** cache implementation. 1881 ** This configuration option is a no-op if an application-defined page 1882 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1883 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1884 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1885 ** and the number of cache lines (N). 1886 ** The sz argument should be the size of the largest database page 1887 ** (a power of two between 512 and 65536) plus some extra bytes for each 1888 ** page header. ^The number of extra bytes needed by the page header 1889 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1890 ** ^It is harmless, apart from the wasted memory, 1891 ** for the sz parameter to be larger than necessary. The pMem 1892 ** argument must be either a NULL pointer or a pointer to an 8-byte 1893 ** aligned block of memory of at least sz*N bytes, otherwise 1894 ** subsequent behavior is undefined. 1895 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1896 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1897 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1898 ** is exhausted. 1899 ** ^If pMem is NULL and N is non-zero, then each database connection 1900 ** does an initial bulk allocation for page cache memory 1901 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1902 ** of -1024*N bytes if N is negative, . ^If additional 1903 ** page cache memory is needed beyond what is provided by the initial 1904 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1905 ** additional cache line. </dd> 1906 ** 1907 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1908 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1909 ** that SQLite will use for all of its dynamic memory allocation needs 1910 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1911 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1912 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1913 ** [SQLITE_ERROR] if invoked otherwise. 1914 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1915 ** An 8-byte aligned pointer to the memory, 1916 ** the number of bytes in the memory buffer, and the minimum allocation size. 1917 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1918 ** to using its default memory allocator (the system malloc() implementation), 1919 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1920 ** memory pointer is not NULL then the alternative memory 1921 ** allocator is engaged to handle all of SQLites memory allocation needs. 1922 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1923 ** boundary or subsequent behavior of SQLite will be undefined. 1924 ** The minimum allocation size is capped at 2**12. Reasonable values 1925 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1926 ** 1927 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1928 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1929 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1930 ** The argument specifies alternative low-level mutex routines to be used 1931 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1932 ** the content of the [sqlite3_mutex_methods] structure before the call to 1933 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1934 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1935 ** the entire mutexing subsystem is omitted from the build and hence calls to 1936 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1937 ** return [SQLITE_ERROR].</dd> 1938 ** 1939 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1940 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1941 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1942 ** [sqlite3_mutex_methods] 1943 ** structure is filled with the currently defined mutex routines.)^ 1944 ** This option can be used to overload the default mutex allocation 1945 ** routines with a wrapper used to track mutex usage for performance 1946 ** profiling or testing, for example. ^If SQLite is compiled with 1947 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1948 ** the entire mutexing subsystem is omitted from the build and hence calls to 1949 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1950 ** return [SQLITE_ERROR].</dd> 1951 ** 1952 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1953 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1954 ** the default size of lookaside memory on each [database connection]. 1955 ** The first argument is the 1956 ** size of each lookaside buffer slot and the second is the number of 1957 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1958 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1959 ** option to [sqlite3_db_config()] can be used to change the lookaside 1960 ** configuration on individual connections.)^ </dd> 1961 ** 1962 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1963 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1964 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1965 ** the interface to a custom page cache implementation.)^ 1966 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1967 ** 1968 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1969 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1970 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1971 ** the current page cache implementation into that object.)^ </dd> 1972 ** 1973 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1974 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1975 ** global [error log]. 1976 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1977 ** function with a call signature of void(*)(void*,int,const char*), 1978 ** and a pointer to void. ^If the function pointer is not NULL, it is 1979 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1980 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1981 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1982 ** passed through as the first parameter to the application-defined logger 1983 ** function whenever that function is invoked. ^The second parameter to 1984 ** the logger function is a copy of the first parameter to the corresponding 1985 ** [sqlite3_log()] call and is intended to be a [result code] or an 1986 ** [extended result code]. ^The third parameter passed to the logger is 1987 ** log message after formatting via [sqlite3_snprintf()]. 1988 ** The SQLite logging interface is not reentrant; the logger function 1989 ** supplied by the application must not invoke any SQLite interface. 1990 ** In a multi-threaded application, the application-defined logger 1991 ** function must be threadsafe. </dd> 1992 ** 1993 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1994 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1995 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1996 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1997 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1998 ** [sqlite3_open16()] or 1999 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2000 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2001 ** connection is opened. ^If it is globally disabled, filenames are 2002 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2003 ** database connection is opened. ^(By default, URI handling is globally 2004 ** disabled. The default value may be changed by compiling with the 2005 ** [SQLITE_USE_URI] symbol defined.)^ 2006 ** 2007 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2008 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2009 ** argument which is interpreted as a boolean in order to enable or disable 2010 ** the use of covering indices for full table scans in the query optimizer. 2011 ** ^The default setting is determined 2012 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2013 ** if that compile-time option is omitted. 2014 ** The ability to disable the use of covering indices for full table scans 2015 ** is because some incorrectly coded legacy applications might malfunction 2016 ** when the optimization is enabled. Providing the ability to 2017 ** disable the optimization allows the older, buggy application code to work 2018 ** without change even with newer versions of SQLite. 2019 ** 2020 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2021 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2022 ** <dd> These options are obsolete and should not be used by new code. 2023 ** They are retained for backwards compatibility but are now no-ops. 2024 ** </dd> 2025 ** 2026 ** [[SQLITE_CONFIG_SQLLOG]] 2027 ** <dt>SQLITE_CONFIG_SQLLOG 2028 ** <dd>This option is only available if sqlite is compiled with the 2029 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2030 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2031 ** The second should be of type (void*). The callback is invoked by the library 2032 ** in three separate circumstances, identified by the value passed as the 2033 ** fourth parameter. If the fourth parameter is 0, then the database connection 2034 ** passed as the second argument has just been opened. The third argument 2035 ** points to a buffer containing the name of the main database file. If the 2036 ** fourth parameter is 1, then the SQL statement that the third parameter 2037 ** points to has just been executed. Or, if the fourth parameter is 2, then 2038 ** the connection being passed as the second parameter is being closed. The 2039 ** third parameter is passed NULL In this case. An example of using this 2040 ** configuration option can be seen in the "test_sqllog.c" source file in 2041 ** the canonical SQLite source tree.</dd> 2042 ** 2043 ** [[SQLITE_CONFIG_MMAP_SIZE]] 2044 ** <dt>SQLITE_CONFIG_MMAP_SIZE 2045 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2046 ** that are the default mmap size limit (the default setting for 2047 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2048 ** ^The default setting can be overridden by each database connection using 2049 ** either the [PRAGMA mmap_size] command, or by using the 2050 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2051 ** will be silently truncated if necessary so that it does not exceed the 2052 ** compile-time maximum mmap size set by the 2053 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2054 ** ^If either argument to this option is negative, then that argument is 2055 ** changed to its compile-time default. 2056 ** 2057 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2058 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2059 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2060 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2061 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2062 ** that specifies the maximum size of the created heap. 2063 ** 2064 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2065 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2066 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2067 ** is a pointer to an integer and writes into that integer the number of extra 2068 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2069 ** The amount of extra space required can change depending on the compiler, 2070 ** target platform, and SQLite version. 2071 ** 2072 ** [[SQLITE_CONFIG_PMASZ]] 2073 ** <dt>SQLITE_CONFIG_PMASZ 2074 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2075 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2076 ** sorter to that integer. The default minimum PMA Size is set by the 2077 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2078 ** to help with sort operations when multithreaded sorting 2079 ** is enabled (using the [PRAGMA threads] command) and the amount of content 2080 ** to be sorted exceeds the page size times the minimum of the 2081 ** [PRAGMA cache_size] setting and this value. 2082 ** 2083 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2084 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2085 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2086 ** becomes the [statement journal] spill-to-disk threshold. 2087 ** [Statement journals] are held in memory until their size (in bytes) 2088 ** exceeds this threshold, at which point they are written to disk. 2089 ** Or if the threshold is -1, statement journals are always held 2090 ** exclusively in memory. 2091 ** Since many statement journals never become large, setting the spill 2092 ** threshold to a value such as 64KiB can greatly reduce the amount of 2093 ** I/O required to support statement rollback. 2094 ** The default value for this setting is controlled by the 2095 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 2096 ** 2097 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2098 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2099 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2100 ** of type (int) - the new value of the sorter-reference size threshold. 2101 ** Usually, when SQLite uses an external sort to order records according 2102 ** to an ORDER BY clause, all fields required by the caller are present in the 2103 ** sorted records. However, if SQLite determines based on the declared type 2104 ** of a table column that its values are likely to be very large - larger 2105 ** than the configured sorter-reference size threshold - then a reference 2106 ** is stored in each sorted record and the required column values loaded 2107 ** from the database as records are returned in sorted order. The default 2108 ** value for this option is to never use this optimization. Specifying a 2109 ** negative value for this option restores the default behaviour. 2110 ** This option is only available if SQLite is compiled with the 2111 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2112 ** 2113 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2114 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2115 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2116 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2117 ** database created using [sqlite3_deserialize()]. This default maximum 2118 ** size can be adjusted up or down for individual databases using the 2119 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2120 ** configuration setting is never used, then the default maximum is determined 2121 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2122 ** compile-time option is not set, then the default maximum is 1073741824. 2123 ** 2124 ** [[SQLITE_CONFIG_CORRUPTION]] <dt>SQLITE_CONFIG_CORRUPTION</dt> 2125 ** <dd> The SQLITE_CONFIG_CORRUPTION option is used to configure the SQLite 2126 ** global [ corruption error]. 2127 ** (^The SQLITE_CONFIG_CORRUPTION option takes two arguments: a pointer to a 2128 ** function with a call signature of void(*)(void*,const void*), 2129 ** and a pointer to void. ^If the function pointer is not NULL, it is 2130 ** invoked to process each data corruption event. ^If the 2131 ** function pointer is NULL, no=op will do when corruption detect. 2132 ** ^The void pointer that is the second argument to SQLITE_CONFIG_CORRUPTION is 2133 ** passed through as the first parameter to the application-defined corruption 2134 ** function whenever that function is invoked. ^The second parameter to 2135 ** the corruption function is a corruption message after formatting via [sqlite3_snprintf()]. 2136 ** In a multi-threaded application, the application-defined corruption 2137 ** function must be threadsafe. </dd> 2138 ** </dl> 2139 */ 2140 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2141 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2142 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2143 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2144 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2145 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2146 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2147 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2148 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2149 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2150 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2151 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2152 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2153 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2154 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2155 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2156 #define SQLITE_CONFIG_URI 17 /* int */ 2157 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2158 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2159 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2160 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2161 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2162 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2163 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2164 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2165 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2166 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2167 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2168 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2169 #define SQLITE_CONFIG_CORRUPTION 30 /* xCorruption */ 2170 #define SQLITE_CONFIG_ENABLE_ICU 31 /* boolean */ 2171 2172 /* 2173 ** CAPI3REF: Database Connection Configuration Options 2174 ** 2175 ** These constants are the available integer configuration options that 2176 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2177 ** 2178 ** New configuration options may be added in future releases of SQLite. 2179 ** Existing configuration options might be discontinued. Applications 2180 ** should check the return code from [sqlite3_db_config()] to make sure that 2181 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2182 ** non-zero [error code] if a discontinued or unsupported configuration option 2183 ** is invoked. 2184 ** 2185 ** <dl> 2186 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2187 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2188 ** <dd> ^This option takes three additional arguments that determine the 2189 ** [lookaside memory allocator] configuration for the [database connection]. 2190 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2191 ** pointer to a memory buffer to use for lookaside memory. 2192 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2193 ** may be NULL in which case SQLite will allocate the 2194 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2195 ** size of each lookaside buffer slot. ^The third argument is the number of 2196 ** slots. The size of the buffer in the first argument must be greater than 2197 ** or equal to the product of the second and third arguments. The buffer 2198 ** must be aligned to an 8-byte boundary. ^If the second argument to 2199 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2200 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2201 ** configuration for a database connection can only be changed when that 2202 ** connection is not currently using lookaside memory, or in other words 2203 ** when the "current value" returned by 2204 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2205 ** Any attempt to change the lookaside memory configuration when lookaside 2206 ** memory is in use leaves the configuration unchanged and returns 2207 ** [SQLITE_BUSY].)^</dd> 2208 ** 2209 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2210 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2211 ** <dd> ^This option is used to enable or disable the enforcement of 2212 ** [foreign key constraints]. There should be two additional arguments. 2213 ** The first argument is an integer which is 0 to disable FK enforcement, 2214 ** positive to enable FK enforcement or negative to leave FK enforcement 2215 ** unchanged. The second parameter is a pointer to an integer into which 2216 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2217 ** following this call. The second parameter may be a NULL pointer, in 2218 ** which case the FK enforcement setting is not reported back. </dd> 2219 ** 2220 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2221 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2222 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2223 ** There should be two additional arguments. 2224 ** The first argument is an integer which is 0 to disable triggers, 2225 ** positive to enable triggers or negative to leave the setting unchanged. 2226 ** The second parameter is a pointer to an integer into which 2227 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2228 ** following this call. The second parameter may be a NULL pointer, in 2229 ** which case the trigger setting is not reported back. 2230 ** 2231 ** <p>Originally this option disabled all triggers. ^(However, since 2232 ** SQLite version 3.35.0, TEMP triggers are still allowed even if 2233 ** this option is off. So, in other words, this option now only disables 2234 ** triggers in the main database schema or in the schemas of ATTACH-ed 2235 ** databases.)^ </dd> 2236 ** 2237 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2238 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2239 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2240 ** There should be two additional arguments. 2241 ** The first argument is an integer which is 0 to disable views, 2242 ** positive to enable views or negative to leave the setting unchanged. 2243 ** The second parameter is a pointer to an integer into which 2244 ** is written 0 or 1 to indicate whether views are disabled or enabled 2245 ** following this call. The second parameter may be a NULL pointer, in 2246 ** which case the view setting is not reported back. 2247 ** 2248 ** <p>Originally this option disabled all views. ^(However, since 2249 ** SQLite version 3.35.0, TEMP views are still allowed even if 2250 ** this option is off. So, in other words, this option now only disables 2251 ** views in the main database schema or in the schemas of ATTACH-ed 2252 ** databases.)^ </dd> 2253 ** 2254 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2255 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2256 ** <dd> ^This option is used to enable or disable the 2257 ** [fts3_tokenizer()] function which is part of the 2258 ** [FTS3] full-text search engine extension. 2259 ** There should be two additional arguments. 2260 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2261 ** positive to enable fts3_tokenizer() or negative to leave the setting 2262 ** unchanged. 2263 ** The second parameter is a pointer to an integer into which 2264 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2265 ** following this call. The second parameter may be a NULL pointer, in 2266 ** which case the new setting is not reported back. </dd> 2267 ** 2268 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2269 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2270 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2271 ** interface independently of the [load_extension()] SQL function. 2272 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2273 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2274 ** There should be two additional arguments. 2275 ** When the first argument to this interface is 1, then only the C-API is 2276 ** enabled and the SQL function remains disabled. If the first argument to 2277 ** this interface is 0, then both the C-API and the SQL function are disabled. 2278 ** If the first argument is -1, then no changes are made to state of either the 2279 ** C-API or the SQL function. 2280 ** The second parameter is a pointer to an integer into which 2281 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2282 ** is disabled or enabled following this call. The second parameter may 2283 ** be a NULL pointer, in which case the new setting is not reported back. 2284 ** </dd> 2285 ** 2286 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2287 ** <dd> ^This option is used to change the name of the "main" database 2288 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2289 ** which will become the new schema name in place of "main". ^SQLite 2290 ** does not make a copy of the new main schema name string, so the application 2291 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2292 ** until after the database connection closes. 2293 ** </dd> 2294 ** 2295 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2296 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2297 ** <dd> Usually, when a database in wal mode is closed or detached from a 2298 ** database handle, SQLite checks if this will mean that there are now no 2299 ** connections at all to the database. If so, it performs a checkpoint 2300 ** operation before closing the connection. This option may be used to 2301 ** override this behaviour. The first parameter passed to this operation 2302 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2303 ** default) to enable them, and negative to leave the setting unchanged. 2304 ** The second parameter is a pointer to an integer 2305 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2306 ** have been disabled - 0 if they are not disabled, 1 if they are. 2307 ** </dd> 2308 ** 2309 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2310 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2311 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2312 ** a single SQL query statement will always use the same algorithm regardless 2313 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2314 ** that look at the values of bound parameters, which can make some queries 2315 ** slower. But the QPSG has the advantage of more predictable behavior. With 2316 ** the QPSG active, SQLite will always use the same query plan in the field as 2317 ** was used during testing in the lab. 2318 ** The first argument to this setting is an integer which is 0 to disable 2319 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2320 ** unchanged. The second parameter is a pointer to an integer into which 2321 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2322 ** following this call. 2323 ** </dd> 2324 ** 2325 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2326 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2327 ** include output for any operations performed by trigger programs. This 2328 ** option is used to set or clear (the default) a flag that governs this 2329 ** behavior. The first parameter passed to this operation is an integer - 2330 ** positive to enable output for trigger programs, or zero to disable it, 2331 ** or negative to leave the setting unchanged. 2332 ** The second parameter is a pointer to an integer into which is written 2333 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2334 ** it is not disabled, 1 if it is. 2335 ** </dd> 2336 ** 2337 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2338 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2339 ** [VACUUM] in order to reset a database back to an empty database 2340 ** with no schema and no content. The following process works even for 2341 ** a badly corrupted database file: 2342 ** <ol> 2343 ** <li> If the database connection is newly opened, make sure it has read the 2344 ** database schema by preparing then discarding some query against the 2345 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2346 ** errors. This step is only necessary if the application desires to keep 2347 ** the database in WAL mode after the reset if it was in WAL mode before 2348 ** the reset. 2349 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2350 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2351 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2352 ** </ol> 2353 ** Because resetting a database is destructive and irreversible, the 2354 ** process requires the use of this obscure API and multiple steps to help 2355 ** ensure that it does not happen by accident. 2356 ** 2357 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2358 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2359 ** "defensive" flag for a database connection. When the defensive 2360 ** flag is enabled, language features that allow ordinary SQL to 2361 ** deliberately corrupt the database file are disabled. The disabled 2362 ** features include but are not limited to the following: 2363 ** <ul> 2364 ** <li> The [PRAGMA writable_schema=ON] statement. 2365 ** <li> The [PRAGMA journal_mode=OFF] statement. 2366 ** <li> The [PRAGMA schema_version=N] statement. 2367 ** <li> Writes to the [sqlite_dbpage] virtual table. 2368 ** <li> Direct writes to [shadow tables]. 2369 ** </ul> 2370 ** </dd> 2371 ** 2372 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2373 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2374 ** "writable_schema" flag. This has the same effect and is logically equivalent 2375 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2376 ** The first argument to this setting is an integer which is 0 to disable 2377 ** the writable_schema, positive to enable writable_schema, or negative to 2378 ** leave the setting unchanged. The second parameter is a pointer to an 2379 ** integer into which is written 0 or 1 to indicate whether the writable_schema 2380 ** is enabled or disabled following this call. 2381 ** </dd> 2382 ** 2383 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2384 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2385 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2386 ** the legacy behavior of the [ALTER TABLE RENAME] command such it 2387 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2388 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2389 ** additional information. This feature can also be turned on and off 2390 ** using the [PRAGMA legacy_alter_table] statement. 2391 ** </dd> 2392 ** 2393 ** [[SQLITE_DBCONFIG_DQS_DML]] 2394 ** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2395 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2396 ** the legacy [double-quoted string literal] misfeature for DML statements 2397 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2398 ** default value of this setting is determined by the [-DSQLITE_DQS] 2399 ** compile-time option. 2400 ** </dd> 2401 ** 2402 ** [[SQLITE_DBCONFIG_DQS_DDL]] 2403 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2404 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2405 ** the legacy [double-quoted string literal] misfeature for DDL statements, 2406 ** such as CREATE TABLE and CREATE INDEX. The 2407 ** default value of this setting is determined by the [-DSQLITE_DQS] 2408 ** compile-time option. 2409 ** </dd> 2410 ** 2411 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2412 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2413 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2414 ** assume that database schemas are untainted by malicious content. 2415 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2416 ** takes additional defensive steps to protect the application from harm 2417 ** including: 2418 ** <ul> 2419 ** <li> Prohibit the use of SQL functions inside triggers, views, 2420 ** CHECK constraints, DEFAULT clauses, expression indexes, 2421 ** partial indexes, or generated columns 2422 ** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2423 ** <li> Prohibit the use of virtual tables inside of triggers or views 2424 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2425 ** </ul> 2426 ** This setting defaults to "on" for legacy compatibility, however 2427 ** all applications are advised to turn it off if possible. This setting 2428 ** can also be controlled using the [PRAGMA trusted_schema] statement. 2429 ** </dd> 2430 ** 2431 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2432 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2433 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2434 ** the legacy file format flag. When activated, this flag causes all newly 2435 ** created database file to have a schema format version number (the 4-byte 2436 ** integer found at offset 44 into the database header) of 1. This in turn 2437 ** means that the resulting database file will be readable and writable by 2438 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2439 ** newly created databases are generally not understandable by SQLite versions 2440 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2441 ** is now scarcely any need to generated database files that are compatible 2442 ** all the way back to version 3.0.0, and so this setting is of little 2443 ** practical use, but is provided so that SQLite can continue to claim the 2444 ** ability to generate new database files that are compatible with version 2445 ** 3.0.0. 2446 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2447 ** the [VACUUM] command will fail with an obscure error when attempting to 2448 ** process a table with generated columns and a descending index. This is 2449 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2450 ** either generated columns or decending indexes. 2451 ** </dd> 2452 ** </dl> 2453 */ 2454 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2455 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2456 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2457 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2458 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2459 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2460 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2461 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2462 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2463 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2464 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2465 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2466 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2467 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2468 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2469 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2470 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2471 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2472 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2473 2474 /* 2475 ** CAPI3REF: Enable Or Disable Extended Result Codes 2476 ** METHOD: sqlite3 2477 ** 2478 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2479 ** [extended result codes] feature of SQLite. ^The extended result 2480 ** codes are disabled by default for historical compatibility. 2481 */ 2482 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2483 2484 /* 2485 ** CAPI3REF: Last Insert Rowid 2486 ** METHOD: sqlite3 2487 ** 2488 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2489 ** has a unique 64-bit signed 2490 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2491 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2492 ** names are not also used by explicitly declared columns. ^If 2493 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2494 ** is another alias for the rowid. 2495 ** 2496 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2497 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2498 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2499 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2500 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2501 ** zero. 2502 ** 2503 ** As well as being set automatically as rows are inserted into database 2504 ** tables, the value returned by this function may be set explicitly by 2505 ** [sqlite3_set_last_insert_rowid()] 2506 ** 2507 ** Some virtual table implementations may INSERT rows into rowid tables as 2508 ** part of committing a transaction (e.g. to flush data accumulated in memory 2509 ** to disk). In this case subsequent calls to this function return the rowid 2510 ** associated with these internal INSERT operations, which leads to 2511 ** unintuitive results. Virtual table implementations that do write to rowid 2512 ** tables in this way can avoid this problem by restoring the original 2513 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2514 ** control to the user. 2515 ** 2516 ** ^(If an [INSERT] occurs within a trigger then this routine will 2517 ** return the [rowid] of the inserted row as long as the trigger is 2518 ** running. Once the trigger program ends, the value returned 2519 ** by this routine reverts to what it was before the trigger was fired.)^ 2520 ** 2521 ** ^An [INSERT] that fails due to a constraint violation is not a 2522 ** successful [INSERT] and does not change the value returned by this 2523 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2524 ** and INSERT OR ABORT make no changes to the return value of this 2525 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2526 ** encounters a constraint violation, it does not fail. The 2527 ** INSERT continues to completion after deleting rows that caused 2528 ** the constraint problem so INSERT OR REPLACE will always change 2529 ** the return value of this interface.)^ 2530 ** 2531 ** ^For the purposes of this routine, an [INSERT] is considered to 2532 ** be successful even if it is subsequently rolled back. 2533 ** 2534 ** This function is accessible to SQL statements via the 2535 ** [last_insert_rowid() SQL function]. 2536 ** 2537 ** If a separate thread performs a new [INSERT] on the same 2538 ** database connection while the [sqlite3_last_insert_rowid()] 2539 ** function is running and thus changes the last insert [rowid], 2540 ** then the value returned by [sqlite3_last_insert_rowid()] is 2541 ** unpredictable and might not equal either the old or the new 2542 ** last insert [rowid]. 2543 */ 2544 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2545 2546 /* 2547 ** CAPI3REF: Set the Last Insert Rowid value. 2548 ** METHOD: sqlite3 2549 ** 2550 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2551 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2552 ** without inserting a row into the database. 2553 */ 2554 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2555 2556 /* 2557 ** CAPI3REF: Count The Number Of Rows Modified 2558 ** METHOD: sqlite3 2559 ** 2560 ** ^These functions return the number of rows modified, inserted or 2561 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2562 ** statement on the database connection specified by the only parameter. 2563 ** The two functions are identical except for the type of the return value 2564 ** and that if the number of rows modified by the most recent INSERT, UPDATE 2565 ** or DELETE is greater than the maximum value supported by type "int", then 2566 ** the return value of sqlite3_changes() is undefined. ^Executing any other 2567 ** type of SQL statement does not modify the value returned by these functions. 2568 ** 2569 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2570 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2571 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2572 ** 2573 ** Changes to a view that are intercepted by 2574 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2575 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2576 ** DELETE statement run on a view is always zero. Only changes made to real 2577 ** tables are counted. 2578 ** 2579 ** Things are more complicated if the sqlite3_changes() function is 2580 ** executed while a trigger program is running. This may happen if the 2581 ** program uses the [changes() SQL function], or if some other callback 2582 ** function invokes sqlite3_changes() directly. Essentially: 2583 ** 2584 ** <ul> 2585 ** <li> ^(Before entering a trigger program the value returned by 2586 ** sqlite3_changes() function is saved. After the trigger program 2587 ** has finished, the original value is restored.)^ 2588 ** 2589 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2590 ** statement sets the value returned by sqlite3_changes() 2591 ** upon completion as normal. Of course, this value will not include 2592 ** any changes performed by sub-triggers, as the sqlite3_changes() 2593 ** value will be saved and restored after each sub-trigger has run.)^ 2594 ** </ul> 2595 ** 2596 ** ^This means that if the changes() SQL function (or similar) is used 2597 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2598 ** returns the value as set when the calling statement began executing. 2599 ** ^If it is used by the second or subsequent such statement within a trigger 2600 ** program, the value returned reflects the number of rows modified by the 2601 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2602 ** 2603 ** If a separate thread makes changes on the same database connection 2604 ** while [sqlite3_changes()] is running then the value returned 2605 ** is unpredictable and not meaningful. 2606 ** 2607 ** See also: 2608 ** <ul> 2609 ** <li> the [sqlite3_total_changes()] interface 2610 ** <li> the [count_changes pragma] 2611 ** <li> the [changes() SQL function] 2612 ** <li> the [data_version pragma] 2613 ** </ul> 2614 */ 2615 SQLITE_API int sqlite3_changes(sqlite3*); 2616 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2617 2618 /* 2619 ** CAPI3REF: Total Number Of Rows Modified 2620 ** METHOD: sqlite3 2621 ** 2622 ** ^These functions return the total number of rows inserted, modified or 2623 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2624 ** since the database connection was opened, including those executed as 2625 ** part of trigger programs. The two functions are identical except for the 2626 ** type of the return value and that if the number of rows modified by the 2627 ** connection exceeds the maximum value supported by type "int", then 2628 ** the return value of sqlite3_total_changes() is undefined. ^Executing 2629 ** any other type of SQL statement does not affect the value returned by 2630 ** sqlite3_total_changes(). 2631 ** 2632 ** ^Changes made as part of [foreign key actions] are included in the 2633 ** count, but those made as part of REPLACE constraint resolution are 2634 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2635 ** are not counted. 2636 ** 2637 ** The [sqlite3_total_changes(D)] interface only reports the number 2638 ** of rows that changed due to SQL statement run against database 2639 ** connection D. Any changes by other database connections are ignored. 2640 ** To detect changes against a database file from other database 2641 ** connections use the [PRAGMA data_version] command or the 2642 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2643 ** 2644 ** If a separate thread makes changes on the same database connection 2645 ** while [sqlite3_total_changes()] is running then the value 2646 ** returned is unpredictable and not meaningful. 2647 ** 2648 ** See also: 2649 ** <ul> 2650 ** <li> the [sqlite3_changes()] interface 2651 ** <li> the [count_changes pragma] 2652 ** <li> the [changes() SQL function] 2653 ** <li> the [data_version pragma] 2654 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2655 ** </ul> 2656 */ 2657 SQLITE_API int sqlite3_total_changes(sqlite3*); 2658 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2659 2660 /* 2661 ** CAPI3REF: Interrupt A Long-Running Query 2662 ** METHOD: sqlite3 2663 ** 2664 ** ^This function causes any pending database operation to abort and 2665 ** return at its earliest opportunity. This routine is typically 2666 ** called in response to a user action such as pressing "Cancel" 2667 ** or Ctrl-C where the user wants a long query operation to halt 2668 ** immediately. 2669 ** 2670 ** ^It is safe to call this routine from a thread different from the 2671 ** thread that is currently running the database operation. But it 2672 ** is not safe to call this routine with a [database connection] that 2673 ** is closed or might close before sqlite3_interrupt() returns. 2674 ** 2675 ** ^If an SQL operation is very nearly finished at the time when 2676 ** sqlite3_interrupt() is called, then it might not have an opportunity 2677 ** to be interrupted and might continue to completion. 2678 ** 2679 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2680 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2681 ** that is inside an explicit transaction, then the entire transaction 2682 ** will be rolled back automatically. 2683 ** 2684 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2685 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2686 ** that are started after the sqlite3_interrupt() call and before the 2687 ** running statement count reaches zero are interrupted as if they had been 2688 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2689 ** that are started after the running statement count reaches zero are 2690 ** not effected by the sqlite3_interrupt(). 2691 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2692 ** SQL statements is a no-op and has no effect on SQL statements 2693 ** that are started after the sqlite3_interrupt() call returns. 2694 */ 2695 SQLITE_API void sqlite3_interrupt(sqlite3*); 2696 2697 /* 2698 ** CAPI3REF: Determine If An SQL Statement Is Complete 2699 ** 2700 ** These routines are useful during command-line input to determine if the 2701 ** currently entered text seems to form a complete SQL statement or 2702 ** if additional input is needed before sending the text into 2703 ** SQLite for parsing. ^These routines return 1 if the input string 2704 ** appears to be a complete SQL statement. ^A statement is judged to be 2705 ** complete if it ends with a semicolon token and is not a prefix of a 2706 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2707 ** string literals or quoted identifier names or comments are not 2708 ** independent tokens (they are part of the token in which they are 2709 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2710 ** and comments that follow the final semicolon are ignored. 2711 ** 2712 ** ^These routines return 0 if the statement is incomplete. ^If a 2713 ** memory allocation fails, then SQLITE_NOMEM is returned. 2714 ** 2715 ** ^These routines do not parse the SQL statements thus 2716 ** will not detect syntactically incorrect SQL. 2717 ** 2718 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2719 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2720 ** automatically by sqlite3_complete16(). If that initialization fails, 2721 ** then the return value from sqlite3_complete16() will be non-zero 2722 ** regardless of whether or not the input SQL is complete.)^ 2723 ** 2724 ** The input to [sqlite3_complete()] must be a zero-terminated 2725 ** UTF-8 string. 2726 ** 2727 ** The input to [sqlite3_complete16()] must be a zero-terminated 2728 ** UTF-16 string in native byte order. 2729 */ 2730 SQLITE_API int sqlite3_complete(const char *sql); 2731 SQLITE_API int sqlite3_complete16(const void *sql); 2732 2733 /* 2734 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2735 ** KEYWORDS: {busy-handler callback} {busy handler} 2736 ** METHOD: sqlite3 2737 ** 2738 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2739 ** that might be invoked with argument P whenever 2740 ** an attempt is made to access a database table associated with 2741 ** [database connection] D when another thread 2742 ** or process has the table locked. 2743 ** The sqlite3_busy_handler() interface is used to implement 2744 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2745 ** 2746 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2747 ** is returned immediately upon encountering the lock. ^If the busy callback 2748 ** is not NULL, then the callback might be invoked with two arguments. 2749 ** 2750 ** ^The first argument to the busy handler is a copy of the void* pointer which 2751 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2752 ** the busy handler callback is the number of times that the busy handler has 2753 ** been invoked previously for the same locking event. ^If the 2754 ** busy callback returns 0, then no additional attempts are made to 2755 ** access the database and [SQLITE_BUSY] is returned 2756 ** to the application. 2757 ** ^If the callback returns non-zero, then another attempt 2758 ** is made to access the database and the cycle repeats. 2759 ** 2760 ** The presence of a busy handler does not guarantee that it will be invoked 2761 ** when there is lock contention. ^If SQLite determines that invoking the busy 2762 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2763 ** to the application instead of invoking the 2764 ** busy handler. 2765 ** Consider a scenario where one process is holding a read lock that 2766 ** it is trying to promote to a reserved lock and 2767 ** a second process is holding a reserved lock that it is trying 2768 ** to promote to an exclusive lock. The first process cannot proceed 2769 ** because it is blocked by the second and the second process cannot 2770 ** proceed because it is blocked by the first. If both processes 2771 ** invoke the busy handlers, neither will make any progress. Therefore, 2772 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2773 ** will induce the first process to release its read lock and allow 2774 ** the second process to proceed. 2775 ** 2776 ** ^The default busy callback is NULL. 2777 ** 2778 ** ^(There can only be a single busy handler defined for each 2779 ** [database connection]. Setting a new busy handler clears any 2780 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2781 ** or evaluating [PRAGMA busy_timeout=N] will change the 2782 ** busy handler and thus clear any previously set busy handler. 2783 ** 2784 ** The busy callback should not take any actions which modify the 2785 ** database connection that invoked the busy handler. In other words, 2786 ** the busy handler is not reentrant. Any such actions 2787 ** result in undefined behavior. 2788 ** 2789 ** A busy handler must not close the database connection 2790 ** or [prepared statement] that invoked the busy handler. 2791 */ 2792 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2793 2794 /* 2795 ** CAPI3REF: Set A Busy Timeout 2796 ** METHOD: sqlite3 2797 ** 2798 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2799 ** for a specified amount of time when a table is locked. ^The handler 2800 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2801 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2802 ** the handler returns 0 which causes [sqlite3_step()] to return 2803 ** [SQLITE_BUSY]. 2804 ** 2805 ** ^Calling this routine with an argument less than or equal to zero 2806 ** turns off all busy handlers. 2807 ** 2808 ** ^(There can only be a single busy handler for a particular 2809 ** [database connection] at any given moment. If another busy handler 2810 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2811 ** this routine, that other busy handler is cleared.)^ 2812 ** 2813 ** See also: [PRAGMA busy_timeout] 2814 */ 2815 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2816 2817 /* 2818 ** CAPI3REF: Convenience Routines For Running Queries 2819 ** METHOD: sqlite3 2820 ** 2821 ** This is a legacy interface that is preserved for backwards compatibility. 2822 ** Use of this interface is not recommended. 2823 ** 2824 ** Definition: A <b>result table</b> is memory data structure created by the 2825 ** [sqlite3_get_table()] interface. A result table records the 2826 ** complete query results from one or more queries. 2827 ** 2828 ** The table conceptually has a number of rows and columns. But 2829 ** these numbers are not part of the result table itself. These 2830 ** numbers are obtained separately. Let N be the number of rows 2831 ** and M be the number of columns. 2832 ** 2833 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2834 ** There are (N+1)*M elements in the array. The first M pointers point 2835 ** to zero-terminated strings that contain the names of the columns. 2836 ** The remaining entries all point to query results. NULL values result 2837 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2838 ** string representation as returned by [sqlite3_column_text()]. 2839 ** 2840 ** A result table might consist of one or more memory allocations. 2841 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2842 ** A result table should be deallocated using [sqlite3_free_table()]. 2843 ** 2844 ** ^(As an example of the result table format, suppose a query result 2845 ** is as follows: 2846 ** 2847 ** <blockquote><pre> 2848 ** Name | Age 2849 ** ----------------------- 2850 ** Alice | 43 2851 ** Bob | 28 2852 ** Cindy | 21 2853 ** </pre></blockquote> 2854 ** 2855 ** There are two columns (M==2) and three rows (N==3). Thus the 2856 ** result table has 8 entries. Suppose the result table is stored 2857 ** in an array named azResult. Then azResult holds this content: 2858 ** 2859 ** <blockquote><pre> 2860 ** azResult[0] = "Name"; 2861 ** azResult[1] = "Age"; 2862 ** azResult[2] = "Alice"; 2863 ** azResult[3] = "43"; 2864 ** azResult[4] = "Bob"; 2865 ** azResult[5] = "28"; 2866 ** azResult[6] = "Cindy"; 2867 ** azResult[7] = "21"; 2868 ** </pre></blockquote>)^ 2869 ** 2870 ** ^The sqlite3_get_table() function evaluates one or more 2871 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2872 ** string of its 2nd parameter and returns a result table to the 2873 ** pointer given in its 3rd parameter. 2874 ** 2875 ** After the application has finished with the result from sqlite3_get_table(), 2876 ** it must pass the result table pointer to sqlite3_free_table() in order to 2877 ** release the memory that was malloced. Because of the way the 2878 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2879 ** function must not try to call [sqlite3_free()] directly. Only 2880 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2881 ** 2882 ** The sqlite3_get_table() interface is implemented as a wrapper around 2883 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2884 ** to any internal data structures of SQLite. It uses only the public 2885 ** interface defined here. As a consequence, errors that occur in the 2886 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2887 ** reflected in subsequent calls to [sqlite3_errcode()] or 2888 ** [sqlite3_errmsg()]. 2889 */ 2890 SQLITE_API int sqlite3_get_table( 2891 sqlite3 *db, /* An open database */ 2892 const char *zSql, /* SQL to be evaluated */ 2893 char ***pazResult, /* Results of the query */ 2894 int *pnRow, /* Number of result rows written here */ 2895 int *pnColumn, /* Number of result columns written here */ 2896 char **pzErrmsg /* Error msg written here */ 2897 ); 2898 SQLITE_API void sqlite3_free_table(char **result); 2899 2900 /* 2901 ** CAPI3REF: Formatted String Printing Functions 2902 ** 2903 ** These routines are work-alikes of the "printf()" family of functions 2904 ** from the standard C library. 2905 ** These routines understand most of the common formatting options from 2906 ** the standard library printf() 2907 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2908 ** See the [built-in printf()] documentation for details. 2909 ** 2910 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2911 ** results into memory obtained from [sqlite3_malloc64()]. 2912 ** The strings returned by these two routines should be 2913 ** released by [sqlite3_free()]. ^Both routines return a 2914 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2915 ** memory to hold the resulting string. 2916 ** 2917 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2918 ** the standard C library. The result is written into the 2919 ** buffer supplied as the second parameter whose size is given by 2920 ** the first parameter. Note that the order of the 2921 ** first two parameters is reversed from snprintf().)^ This is an 2922 ** historical accident that cannot be fixed without breaking 2923 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2924 ** returns a pointer to its buffer instead of the number of 2925 ** characters actually written into the buffer.)^ We admit that 2926 ** the number of characters written would be a more useful return 2927 ** value but we cannot change the implementation of sqlite3_snprintf() 2928 ** now without breaking compatibility. 2929 ** 2930 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2931 ** guarantees that the buffer is always zero-terminated. ^The first 2932 ** parameter "n" is the total size of the buffer, including space for 2933 ** the zero terminator. So the longest string that can be completely 2934 ** written will be n-1 characters. 2935 ** 2936 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2937 ** 2938 ** See also: [built-in printf()], [printf() SQL function] 2939 */ 2940 SQLITE_API char *sqlite3_mprintf(const char*,...); 2941 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2942 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2943 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2944 2945 /* 2946 ** CAPI3REF: Memory Allocation Subsystem 2947 ** 2948 ** The SQLite core uses these three routines for all of its own 2949 ** internal memory allocation needs. "Core" in the previous sentence 2950 ** does not include operating-system specific [VFS] implementation. The 2951 ** Windows VFS uses native malloc() and free() for some operations. 2952 ** 2953 ** ^The sqlite3_malloc() routine returns a pointer to a block 2954 ** of memory at least N bytes in length, where N is the parameter. 2955 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2956 ** memory, it returns a NULL pointer. ^If the parameter N to 2957 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2958 ** a NULL pointer. 2959 ** 2960 ** ^The sqlite3_malloc64(N) routine works just like 2961 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2962 ** of a signed 32-bit integer. 2963 ** 2964 ** ^Calling sqlite3_free() with a pointer previously returned 2965 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2966 ** that it might be reused. ^The sqlite3_free() routine is 2967 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2968 ** to sqlite3_free() is harmless. After being freed, memory 2969 ** should neither be read nor written. Even reading previously freed 2970 ** memory might result in a segmentation fault or other severe error. 2971 ** Memory corruption, a segmentation fault, or other severe error 2972 ** might result if sqlite3_free() is called with a non-NULL pointer that 2973 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2974 ** 2975 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2976 ** prior memory allocation X to be at least N bytes. 2977 ** ^If the X parameter to sqlite3_realloc(X,N) 2978 ** is a NULL pointer then its behavior is identical to calling 2979 ** sqlite3_malloc(N). 2980 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2981 ** negative then the behavior is exactly the same as calling 2982 ** sqlite3_free(X). 2983 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2984 ** of at least N bytes in size or NULL if insufficient memory is available. 2985 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2986 ** of the prior allocation are copied into the beginning of buffer returned 2987 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2988 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2989 ** prior allocation is not freed. 2990 ** 2991 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2992 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2993 ** of a 32-bit signed integer. 2994 ** 2995 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2996 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2997 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2998 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2999 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 3000 ** sqlite3_msize(X) returns zero. If X points to something that is not 3001 ** the beginning of memory allocation, or if it points to a formerly 3002 ** valid memory allocation that has now been freed, then the behavior 3003 ** of sqlite3_msize(X) is undefined and possibly harmful. 3004 ** 3005 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 3006 ** sqlite3_malloc64(), and sqlite3_realloc64() 3007 ** is always aligned to at least an 8 byte boundary, or to a 3008 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 3009 ** option is used. 3010 ** 3011 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 3012 ** must be either NULL or else pointers obtained from a prior 3013 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 3014 ** not yet been released. 3015 ** 3016 ** The application must not read or write any part of 3017 ** a block of memory after it has been released using 3018 ** [sqlite3_free()] or [sqlite3_realloc()]. 3019 */ 3020 SQLITE_API void *sqlite3_malloc(int); 3021 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3022 SQLITE_API void *sqlite3_realloc(void*, int); 3023 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3024 SQLITE_API void sqlite3_free(void*); 3025 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3026 3027 /* 3028 ** CAPI3REF: Memory Allocator Statistics 3029 ** 3030 ** SQLite provides these two interfaces for reporting on the status 3031 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3032 ** routines, which form the built-in memory allocation subsystem. 3033 ** 3034 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 3035 ** of memory currently outstanding (malloced but not freed). 3036 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 3037 ** value of [sqlite3_memory_used()] since the high-water mark 3038 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 3039 ** [sqlite3_memory_highwater()] include any overhead 3040 ** added by SQLite in its implementation of [sqlite3_malloc()], 3041 ** but not overhead added by the any underlying system library 3042 ** routines that [sqlite3_malloc()] may call. 3043 ** 3044 ** ^The memory high-water mark is reset to the current value of 3045 ** [sqlite3_memory_used()] if and only if the parameter to 3046 ** [sqlite3_memory_highwater()] is true. ^The value returned 3047 ** by [sqlite3_memory_highwater(1)] is the high-water mark 3048 ** prior to the reset. 3049 */ 3050 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3051 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3052 3053 /* 3054 ** CAPI3REF: Pseudo-Random Number Generator 3055 ** 3056 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3057 ** select random [ROWID | ROWIDs] when inserting new records into a table that 3058 ** already uses the largest possible [ROWID]. The PRNG is also used for 3059 ** the built-in random() and randomblob() SQL functions. This interface allows 3060 ** applications to access the same PRNG for other purposes. 3061 ** 3062 ** ^A call to this routine stores N bytes of randomness into buffer P. 3063 ** ^The P parameter can be a NULL pointer. 3064 ** 3065 ** ^If this routine has not been previously called or if the previous 3066 ** call had N less than one or a NULL pointer for P, then the PRNG is 3067 ** seeded using randomness obtained from the xRandomness method of 3068 ** the default [sqlite3_vfs] object. 3069 ** ^If the previous call to this routine had an N of 1 or more and a 3070 ** non-NULL P then the pseudo-randomness is generated 3071 ** internally and without recourse to the [sqlite3_vfs] xRandomness 3072 ** method. 3073 */ 3074 SQLITE_API void sqlite3_randomness(int N, void *P); 3075 3076 /* 3077 ** CAPI3REF: Compile-Time Authorization Callbacks 3078 ** METHOD: sqlite3 3079 ** KEYWORDS: {authorizer callback} 3080 ** 3081 ** ^This routine registers an authorizer callback with a particular 3082 ** [database connection], supplied in the first argument. 3083 ** ^The authorizer callback is invoked as SQL statements are being compiled 3084 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3085 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3086 ** and [sqlite3_prepare16_v3()]. ^At various 3087 ** points during the compilation process, as logic is being created 3088 ** to perform various actions, the authorizer callback is invoked to 3089 ** see if those actions are allowed. ^The authorizer callback should 3090 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3091 ** specific action but allow the SQL statement to continue to be 3092 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3093 ** rejected with an error. ^If the authorizer callback returns 3094 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3095 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3096 ** the authorizer will fail with an error message. 3097 ** 3098 ** When the callback returns [SQLITE_OK], that means the operation 3099 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 3100 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 3101 ** authorizer will fail with an error message explaining that 3102 ** access is denied. 3103 ** 3104 ** ^The first parameter to the authorizer callback is a copy of the third 3105 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3106 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 3107 ** the particular action to be authorized. ^The third through sixth parameters 3108 ** to the callback are either NULL pointers or zero-terminated strings 3109 ** that contain additional details about the action to be authorized. 3110 ** Applications must always be prepared to encounter a NULL pointer in any 3111 ** of the third through the sixth parameters of the authorization callback. 3112 ** 3113 ** ^If the action code is [SQLITE_READ] 3114 ** and the callback returns [SQLITE_IGNORE] then the 3115 ** [prepared statement] statement is constructed to substitute 3116 ** a NULL value in place of the table column that would have 3117 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3118 ** return can be used to deny an untrusted user access to individual 3119 ** columns of a table. 3120 ** ^When a table is referenced by a [SELECT] but no column values are 3121 ** extracted from that table (for example in a query like 3122 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3123 ** is invoked once for that table with a column name that is an empty string. 3124 ** ^If the action code is [SQLITE_DELETE] and the callback returns 3125 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3126 ** [truncate optimization] is disabled and all rows are deleted individually. 3127 ** 3128 ** An authorizer is used when [sqlite3_prepare | preparing] 3129 ** SQL statements from an untrusted source, to ensure that the SQL statements 3130 ** do not try to access data they are not allowed to see, or that they do not 3131 ** try to execute malicious statements that damage the database. For 3132 ** example, an application may allow a user to enter arbitrary 3133 ** SQL queries for evaluation by a database. But the application does 3134 ** not want the user to be able to make arbitrary changes to the 3135 ** database. An authorizer could then be put in place while the 3136 ** user-entered SQL is being [sqlite3_prepare | prepared] that 3137 ** disallows everything except [SELECT] statements. 3138 ** 3139 ** Applications that need to process SQL from untrusted sources 3140 ** might also consider lowering resource limits using [sqlite3_limit()] 3141 ** and limiting database size using the [max_page_count] [PRAGMA] 3142 ** in addition to using an authorizer. 3143 ** 3144 ** ^(Only a single authorizer can be in place on a database connection 3145 ** at a time. Each call to sqlite3_set_authorizer overrides the 3146 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3147 ** The authorizer is disabled by default. 3148 ** 3149 ** The authorizer callback must not do anything that will modify 3150 ** the database connection that invoked the authorizer callback. 3151 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3152 ** database connections for the meaning of "modify" in this paragraph. 3153 ** 3154 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3155 ** statement might be re-prepared during [sqlite3_step()] due to a 3156 ** schema change. Hence, the application should ensure that the 3157 ** correct authorizer callback remains in place during the [sqlite3_step()]. 3158 ** 3159 ** ^Note that the authorizer callback is invoked only during 3160 ** [sqlite3_prepare()] or its variants. Authorization is not 3161 ** performed during statement evaluation in [sqlite3_step()], unless 3162 ** as stated in the previous paragraph, sqlite3_step() invokes 3163 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3164 */ 3165 SQLITE_API int sqlite3_set_authorizer( 3166 sqlite3*, 3167 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3168 void *pUserData 3169 ); 3170 3171 #ifdef SQLITE_ENABLE_DROPTABLE_CALLBACK 3172 SQLITE_API int sqlite3_set_droptable_handle( 3173 sqlite3 *db, 3174 void (*xFunc)(sqlite3*,const char*,const char*) 3175 ); 3176 #endif 3177 3178 /* 3179 ** CAPI3REF: Authorizer Return Codes 3180 ** 3181 ** The [sqlite3_set_authorizer | authorizer callback function] must 3182 ** return either [SQLITE_OK] or one of these two constants in order 3183 ** to signal SQLite whether or not the action is permitted. See the 3184 ** [sqlite3_set_authorizer | authorizer documentation] for additional 3185 ** information. 3186 ** 3187 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3188 ** returned from the [sqlite3_vtab_on_conflict()] interface. 3189 */ 3190 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3191 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3192 3193 /* 3194 ** CAPI3REF: Authorizer Action Codes 3195 ** 3196 ** The [sqlite3_set_authorizer()] interface registers a callback function 3197 ** that is invoked to authorize certain SQL statement actions. The 3198 ** second parameter to the callback is an integer code that specifies 3199 ** what action is being authorized. These are the integer action codes that 3200 ** the authorizer callback may be passed. 3201 ** 3202 ** These action code values signify what kind of operation is to be 3203 ** authorized. The 3rd and 4th parameters to the authorization 3204 ** callback function will be parameters or NULL depending on which of these 3205 ** codes is used as the second parameter. ^(The 5th parameter to the 3206 ** authorizer callback is the name of the database ("main", "temp", 3207 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3208 ** is the name of the inner-most trigger or view that is responsible for 3209 ** the access attempt or NULL if this access attempt is directly from 3210 ** top-level SQL code. 3211 */ 3212 /******************************************* 3rd ************ 4th ***********/ 3213 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3214 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3215 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3216 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3217 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3218 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3219 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3220 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3221 #define SQLITE_DELETE 9 /* Table Name NULL */ 3222 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3223 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3224 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3225 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3226 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3227 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3228 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3229 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3230 #define SQLITE_INSERT 18 /* Table Name NULL */ 3231 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3232 #define SQLITE_READ 20 /* Table Name Column Name */ 3233 #define SQLITE_SELECT 21 /* NULL NULL */ 3234 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 3235 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 3236 #define SQLITE_ATTACH 24 /* Filename NULL */ 3237 #define SQLITE_DETACH 25 /* Database Name NULL */ 3238 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3239 #define SQLITE_REINDEX 27 /* Index Name NULL */ 3240 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 3241 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3242 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3243 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 3244 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3245 #define SQLITE_COPY 0 /* No longer used */ 3246 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 3247 3248 /* 3249 ** CAPI3REF: Tracing And Profiling Functions 3250 ** METHOD: sqlite3 3251 ** 3252 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3253 ** instead of the routines described here. 3254 ** 3255 ** These routines register callback functions that can be used for 3256 ** tracing and profiling the execution of SQL statements. 3257 ** 3258 ** ^The callback function registered by sqlite3_trace() is invoked at 3259 ** various times when an SQL statement is being run by [sqlite3_step()]. 3260 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3261 ** SQL statement text as the statement first begins executing. 3262 ** ^(Additional sqlite3_trace() callbacks might occur 3263 ** as each triggered subprogram is entered. The callbacks for triggers 3264 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 3265 ** 3266 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3267 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3268 ** 3269 ** ^The callback function registered by sqlite3_profile() is invoked 3270 ** as each SQL statement finishes. ^The profile callback contains 3271 ** the original statement text and an estimate of wall-clock time 3272 ** of how long that statement took to run. ^The profile callback 3273 ** time is in units of nanoseconds, however the current implementation 3274 ** is only capable of millisecond resolution so the six least significant 3275 ** digits in the time are meaningless. Future versions of SQLite 3276 ** might provide greater resolution on the profiler callback. Invoking 3277 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3278 ** profile callback. 3279 */ 3280 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3281 void(*xTrace)(void*,const char*), void*); 3282 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3283 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3284 3285 /* 3286 ** CAPI3REF: SQL Trace Event Codes 3287 ** KEYWORDS: SQLITE_TRACE 3288 ** 3289 ** These constants identify classes of events that can be monitored 3290 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3291 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3292 ** the following constants. ^The first argument to the trace callback 3293 ** is one of the following constants. 3294 ** 3295 ** New tracing constants may be added in future releases. 3296 ** 3297 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3298 ** ^The T argument is one of the integer type codes above. 3299 ** ^The C argument is a copy of the context pointer passed in as the 3300 ** fourth argument to [sqlite3_trace_v2()]. 3301 ** The P and X arguments are pointers whose meanings depend on T. 3302 ** 3303 ** <dl> 3304 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3305 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3306 ** first begins running and possibly at other times during the 3307 ** execution of the prepared statement, such as at the start of each 3308 ** trigger subprogram. ^The P argument is a pointer to the 3309 ** [prepared statement]. ^The X argument is a pointer to a string which 3310 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3311 ** that indicates the invocation of a trigger. ^The callback can compute 3312 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3313 ** interface by using the X argument when X begins with "--" and invoking 3314 ** [sqlite3_expanded_sql(P)] otherwise. 3315 ** 3316 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3317 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3318 ** information as is provided by the [sqlite3_profile()] callback. 3319 ** ^The P argument is a pointer to the [prepared statement] and the 3320 ** X argument points to a 64-bit integer which is the estimated of 3321 ** the number of nanosecond that the prepared statement took to run. 3322 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3323 ** 3324 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3325 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3326 ** statement generates a single row of result. 3327 ** ^The P argument is a pointer to the [prepared statement] and the 3328 ** X argument is unused. 3329 ** 3330 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3331 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3332 ** connection closes. 3333 ** ^The P argument is a pointer to the [database connection] object 3334 ** and the X argument is unused. 3335 ** </dl> 3336 */ 3337 #define SQLITE_TRACE_STMT 0x01 3338 #define SQLITE_TRACE_PROFILE 0x02 3339 #define SQLITE_TRACE_ROW 0x04 3340 #define SQLITE_TRACE_CLOSE 0x08 3341 3342 /* 3343 ** CAPI3REF: SQL Trace Hook 3344 ** METHOD: sqlite3 3345 ** 3346 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3347 ** function X against [database connection] D, using property mask M 3348 ** and context pointer P. ^If the X callback is 3349 ** NULL or if the M mask is zero, then tracing is disabled. The 3350 ** M argument should be the bitwise OR-ed combination of 3351 ** zero or more [SQLITE_TRACE] constants. 3352 ** 3353 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3354 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3355 ** 3356 ** ^The X callback is invoked whenever any of the events identified by 3357 ** mask M occur. ^The integer return value from the callback is currently 3358 ** ignored, though this may change in future releases. Callback 3359 ** implementations should return zero to ensure future compatibility. 3360 ** 3361 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3362 ** ^The T argument is one of the [SQLITE_TRACE] 3363 ** constants to indicate why the callback was invoked. 3364 ** ^The C argument is a copy of the context pointer. 3365 ** The P and X arguments are pointers whose meanings depend on T. 3366 ** 3367 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3368 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3369 ** are deprecated. 3370 */ 3371 SQLITE_API int sqlite3_trace_v2( 3372 sqlite3*, 3373 unsigned uMask, 3374 int(*xCallback)(unsigned,void*,void*,void*), 3375 void *pCtx 3376 ); 3377 3378 /* 3379 ** CAPI3REF: Query Progress Callbacks 3380 ** METHOD: sqlite3 3381 ** 3382 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3383 ** function X to be invoked periodically during long running calls to 3384 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3385 ** database connection D. An example use for this 3386 ** interface is to keep a GUI updated during a large query. 3387 ** 3388 ** ^The parameter P is passed through as the only parameter to the 3389 ** callback function X. ^The parameter N is the approximate number of 3390 ** [virtual machine instructions] that are evaluated between successive 3391 ** invocations of the callback X. ^If N is less than one then the progress 3392 ** handler is disabled. 3393 ** 3394 ** ^Only a single progress handler may be defined at one time per 3395 ** [database connection]; setting a new progress handler cancels the 3396 ** old one. ^Setting parameter X to NULL disables the progress handler. 3397 ** ^The progress handler is also disabled by setting N to a value less 3398 ** than 1. 3399 ** 3400 ** ^If the progress callback returns non-zero, the operation is 3401 ** interrupted. This feature can be used to implement a 3402 ** "Cancel" button on a GUI progress dialog box. 3403 ** 3404 ** The progress handler callback must not do anything that will modify 3405 ** the database connection that invoked the progress handler. 3406 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3407 ** database connections for the meaning of "modify" in this paragraph. 3408 ** 3409 */ 3410 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3411 3412 /* 3413 ** CAPI3REF: Opening A New Database Connection 3414 ** CONSTRUCTOR: sqlite3 3415 ** 3416 ** ^These routines open an SQLite database file as specified by the 3417 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3418 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3419 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3420 ** returned in *ppDb, even if an error occurs. The only exception is that 3421 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3422 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3423 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3424 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3425 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3426 ** an English language description of the error following a failure of any 3427 ** of the sqlite3_open() routines. 3428 ** 3429 ** ^The default encoding will be UTF-8 for databases created using 3430 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3431 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3432 ** 3433 ** Whether or not an error occurs when it is opened, resources 3434 ** associated with the [database connection] handle should be released by 3435 ** passing it to [sqlite3_close()] when it is no longer required. 3436 ** 3437 ** The sqlite3_open_v2() interface works like sqlite3_open() 3438 ** except that it accepts two additional parameters for additional control 3439 ** over the new database connection. ^(The flags parameter to 3440 ** sqlite3_open_v2() must include, at a minimum, one of the following 3441 ** three flag combinations:)^ 3442 ** 3443 ** <dl> 3444 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3445 ** <dd>The database is opened in read-only mode. If the database does not 3446 ** already exist, an error is returned.</dd>)^ 3447 ** 3448 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3449 ** <dd>The database is opened for reading and writing if possible, or reading 3450 ** only if the file is write protected by the operating system. In either 3451 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3452 ** 3453 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3454 ** <dd>The database is opened for reading and writing, and is created if 3455 ** it does not already exist. This is the behavior that is always used for 3456 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3457 ** </dl> 3458 ** 3459 ** In addition to the required flags, the following optional flags are 3460 ** also supported: 3461 ** 3462 ** <dl> 3463 ** ^(<dt>[SQLITE_OPEN_URI]</dt> 3464 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3465 ** 3466 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3467 ** <dd>The database will be opened as an in-memory database. The database 3468 ** is named by the "filename" argument for the purposes of cache-sharing, 3469 ** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3470 ** </dd>)^ 3471 ** 3472 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3473 ** <dd>The new database connection will use the "multi-thread" 3474 ** [threading mode].)^ This means that separate threads are allowed 3475 ** to use SQLite at the same time, as long as each thread is using 3476 ** a different [database connection]. 3477 ** 3478 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3479 ** <dd>The new database connection will use the "serialized" 3480 ** [threading mode].)^ This means the multiple threads can safely 3481 ** attempt to use the same database connection at the same time. 3482 ** (Mutexes will block any actual concurrency, but in this mode 3483 ** there is no harm in trying.) 3484 ** 3485 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3486 ** <dd>The database is opened [shared cache] enabled, overriding 3487 ** the default shared cache setting provided by 3488 ** [sqlite3_enable_shared_cache()].)^ 3489 ** The [use of shared cache mode is discouraged] and hence shared cache 3490 ** capabilities may be omitted from many builds of SQLite. In such cases, 3491 ** this option is a no-op. 3492 ** 3493 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3494 ** <dd>The database is opened [shared cache] disabled, overriding 3495 ** the default shared cache setting provided by 3496 ** [sqlite3_enable_shared_cache()].)^ 3497 ** 3498 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3499 ** <dd>The database connection comes up in "extended result code mode". 3500 ** In other words, the database behaves has if 3501 ** [sqlite3_extended_result_codes(db,1)] where called on the database 3502 ** connection as soon as the connection is created. In addition to setting 3503 ** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3504 ** to return an extended result code.</dd> 3505 ** 3506 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3507 ** <dd>The database filename is not allowed to contain a symbolic link</dd> 3508 ** </dl>)^ 3509 ** 3510 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3511 ** required combinations shown above optionally combined with other 3512 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3513 ** then the behavior is undefined. Historic versions of SQLite 3514 ** have silently ignored surplus bits in the flags parameter to 3515 ** sqlite3_open_v2(), however that behavior might not be carried through 3516 ** into future versions of SQLite and so applications should not rely 3517 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3518 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3519 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3520 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3521 ** by sqlite3_open_v2(). 3522 ** 3523 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3524 ** [sqlite3_vfs] object that defines the operating system interface that 3525 ** the new database connection should use. ^If the fourth parameter is 3526 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3527 ** 3528 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3529 ** is created for the connection. ^This in-memory database will vanish when 3530 ** the database connection is closed. Future versions of SQLite might 3531 ** make use of additional special filenames that begin with the ":" character. 3532 ** It is recommended that when a database filename actually does begin with 3533 ** a ":" character you should prefix the filename with a pathname such as 3534 ** "./" to avoid ambiguity. 3535 ** 3536 ** ^If the filename is an empty string, then a private, temporary 3537 ** on-disk database will be created. ^This private database will be 3538 ** automatically deleted as soon as the database connection is closed. 3539 ** 3540 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3541 ** 3542 ** ^If [URI filename] interpretation is enabled, and the filename argument 3543 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3544 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3545 ** set in the third argument to sqlite3_open_v2(), or if it has 3546 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3547 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3548 ** URI filename interpretation is turned off 3549 ** by default, but future releases of SQLite might enable URI filename 3550 ** interpretation by default. See "[URI filenames]" for additional 3551 ** information. 3552 ** 3553 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3554 ** authority, then it must be either an empty string or the string 3555 ** "localhost". ^If the authority is not an empty string or "localhost", an 3556 ** error is returned to the caller. ^The fragment component of a URI, if 3557 ** present, is ignored. 3558 ** 3559 ** ^SQLite uses the path component of the URI as the name of the disk file 3560 ** which contains the database. ^If the path begins with a '/' character, 3561 ** then it is interpreted as an absolute path. ^If the path does not begin 3562 ** with a '/' (meaning that the authority section is omitted from the URI) 3563 ** then the path is interpreted as a relative path. 3564 ** ^(On windows, the first component of an absolute path 3565 ** is a drive specification (e.g. "C:").)^ 3566 ** 3567 ** [[core URI query parameters]] 3568 ** The query component of a URI may contain parameters that are interpreted 3569 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3570 ** SQLite and its built-in [VFSes] interpret the 3571 ** following query parameters: 3572 ** 3573 ** <ul> 3574 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3575 ** a VFS object that provides the operating system interface that should 3576 ** be used to access the database file on disk. ^If this option is set to 3577 ** an empty string the default VFS object is used. ^Specifying an unknown 3578 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3579 ** present, then the VFS specified by the option takes precedence over 3580 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3581 ** 3582 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3583 ** "rwc", or "memory". Attempting to set it to any other value is 3584 ** an error)^. 3585 ** ^If "ro" is specified, then the database is opened for read-only 3586 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3587 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3588 ** "rw", then the database is opened for read-write (but not create) 3589 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3590 ** been set. ^Value "rwc" is equivalent to setting both 3591 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3592 ** set to "memory" then a pure [in-memory database] that never reads 3593 ** or writes from disk is used. ^It is an error to specify a value for 3594 ** the mode parameter that is less restrictive than that specified by 3595 ** the flags passed in the third parameter to sqlite3_open_v2(). 3596 ** 3597 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3598 ** "private". ^Setting it to "shared" is equivalent to setting the 3599 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3600 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3601 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3602 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3603 ** a URI filename, its value overrides any behavior requested by setting 3604 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3605 ** 3606 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3607 ** [powersafe overwrite] property does or does not apply to the 3608 ** storage media on which the database file resides. 3609 ** 3610 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3611 ** which if set disables file locking in rollback journal modes. This 3612 ** is useful for accessing a database on a filesystem that does not 3613 ** support locking. Caution: Database corruption might result if two 3614 ** or more processes write to the same database and any one of those 3615 ** processes uses nolock=1. 3616 ** 3617 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3618 ** parameter that indicates that the database file is stored on 3619 ** read-only media. ^When immutable is set, SQLite assumes that the 3620 ** database file cannot be changed, even by a process with higher 3621 ** privilege, and so the database is opened read-only and all locking 3622 ** and change detection is disabled. Caution: Setting the immutable 3623 ** property on a database file that does in fact change can result 3624 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3625 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3626 ** 3627 ** </ul> 3628 ** 3629 ** ^Specifying an unknown parameter in the query component of a URI is not an 3630 ** error. Future versions of SQLite might understand additional query 3631 ** parameters. See "[query parameters with special meaning to SQLite]" for 3632 ** additional information. 3633 ** 3634 ** [[URI filename examples]] <h3>URI filename examples</h3> 3635 ** 3636 ** <table border="1" align=center cellpadding=5> 3637 ** <tr><th> URI filenames <th> Results 3638 ** <tr><td> file:data.db <td> 3639 ** Open the file "data.db" in the current directory. 3640 ** <tr><td> file:/home/fred/data.db<br> 3641 ** file:///home/fred/data.db <br> 3642 ** file://localhost/home/fred/data.db <br> <td> 3643 ** Open the database file "/home/fred/data.db". 3644 ** <tr><td> file://darkstar/home/fred/data.db <td> 3645 ** An error. "darkstar" is not a recognized authority. 3646 ** <tr><td style="white-space:nowrap"> 3647 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3648 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3649 ** C:. Note that the %20 escaping in this example is not strictly 3650 ** necessary - space characters can be used literally 3651 ** in URI filenames. 3652 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3653 ** Open file "data.db" in the current directory for read-only access. 3654 ** Regardless of whether or not shared-cache mode is enabled by 3655 ** default, use a private cache. 3656 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3657 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3658 ** that uses dot-files in place of posix advisory locking. 3659 ** <tr><td> file:data.db?mode=readonly <td> 3660 ** An error. "readonly" is not a valid option for the "mode" parameter. 3661 ** Use "ro" instead: "file:data.db?mode=ro". 3662 ** </table> 3663 ** 3664 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3665 ** query components of a URI. A hexadecimal escape sequence consists of a 3666 ** percent sign - "%" - followed by exactly two hexadecimal digits 3667 ** specifying an octet value. ^Before the path or query components of a 3668 ** URI filename are interpreted, they are encoded using UTF-8 and all 3669 ** hexadecimal escape sequences replaced by a single byte containing the 3670 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3671 ** the results are undefined. 3672 ** 3673 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3674 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3675 ** codepage is currently defined. Filenames containing international 3676 ** characters must be converted to UTF-8 prior to passing them into 3677 ** sqlite3_open() or sqlite3_open_v2(). 3678 ** 3679 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3680 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3681 ** features that require the use of temporary files may fail. 3682 ** 3683 ** See also: [sqlite3_temp_directory] 3684 */ 3685 SQLITE_API int sqlite3_open( 3686 const char *filename, /* Database filename (UTF-8) */ 3687 sqlite3 **ppDb /* OUT: SQLite db handle */ 3688 ); 3689 SQLITE_API int sqlite3_open16( 3690 const void *filename, /* Database filename (UTF-16) */ 3691 sqlite3 **ppDb /* OUT: SQLite db handle */ 3692 ); 3693 SQLITE_API int sqlite3_open_v2( 3694 const char *filename, /* Database filename (UTF-8) */ 3695 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3696 int flags, /* Flags */ 3697 const char *zVfs /* Name of VFS module to use */ 3698 ); 3699 3700 /* 3701 ** CAPI3REF: Obtain Values For URI Parameters 3702 ** 3703 ** These are utility routines, useful to [VFS|custom VFS implementations], 3704 ** that check if a database file was a URI that contained a specific query 3705 ** parameter, and if so obtains the value of that query parameter. 3706 ** 3707 ** The first parameter to these interfaces (hereafter referred to 3708 ** as F) must be one of: 3709 ** <ul> 3710 ** <li> A database filename pointer created by the SQLite core and 3711 ** passed into the xOpen() method of a VFS implemention, or 3712 ** <li> A filename obtained from [sqlite3_db_filename()], or 3713 ** <li> A new filename constructed using [sqlite3_create_filename()]. 3714 ** </ul> 3715 ** If the F parameter is not one of the above, then the behavior is 3716 ** undefined and probably undesirable. Older versions of SQLite were 3717 ** more tolerant of invalid F parameters than newer versions. 3718 ** 3719 ** If F is a suitable filename (as described in the previous paragraph) 3720 ** and if P is the name of the query parameter, then 3721 ** sqlite3_uri_parameter(F,P) returns the value of the P 3722 ** parameter if it exists or a NULL pointer if P does not appear as a 3723 ** query parameter on F. If P is a query parameter of F and it 3724 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3725 ** a pointer to an empty string. 3726 ** 3727 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3728 ** parameter and returns true (1) or false (0) according to the value 3729 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3730 ** value of query parameter P is one of "yes", "true", or "on" in any 3731 ** case or if the value begins with a non-zero number. The 3732 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3733 ** query parameter P is one of "no", "false", or "off" in any case or 3734 ** if the value begins with a numeric zero. If P is not a query 3735 ** parameter on F or if the value of P does not match any of the 3736 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3737 ** 3738 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3739 ** 64-bit signed integer and returns that integer, or D if P does not 3740 ** exist. If the value of P is something other than an integer, then 3741 ** zero is returned. 3742 ** 3743 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3744 ** the value) of the N-th query parameter for filename F, or a NULL 3745 ** pointer if N is less than zero or greater than the number of query 3746 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3747 ** the name of the first query parameter, 1 for the second parameter, and 3748 ** so forth. 3749 ** 3750 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3751 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3752 ** is not a database file pathname pointer that the SQLite core passed 3753 ** into the xOpen VFS method, then the behavior of this routine is undefined 3754 ** and probably undesirable. 3755 ** 3756 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3757 ** parameter can also be the name of a rollback journal file or WAL file 3758 ** in addition to the main database file. Prior to version 3.31.0, these 3759 ** routines would only work if F was the name of the main database file. 3760 ** When the F parameter is the name of the rollback journal or WAL file, 3761 ** it has access to all the same query parameters as were found on the 3762 ** main database file. 3763 ** 3764 ** See the [URI filename] documentation for additional information. 3765 */ 3766 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3767 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3768 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3769 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3770 3771 /* 3772 ** CAPI3REF: Translate filenames 3773 ** 3774 ** These routines are available to [VFS|custom VFS implementations] for 3775 ** translating filenames between the main database file, the journal file, 3776 ** and the WAL file. 3777 ** 3778 ** If F is the name of an sqlite database file, journal file, or WAL file 3779 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3780 ** returns the name of the corresponding database file. 3781 ** 3782 ** If F is the name of an sqlite database file, journal file, or WAL file 3783 ** passed by the SQLite core into the VFS, or if F is a database filename 3784 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3785 ** returns the name of the corresponding rollback journal file. 3786 ** 3787 ** If F is the name of an sqlite database file, journal file, or WAL file 3788 ** that was passed by the SQLite core into the VFS, or if F is a database 3789 ** filename obtained from [sqlite3_db_filename()], then 3790 ** sqlite3_filename_wal(F) returns the name of the corresponding 3791 ** WAL file. 3792 ** 3793 ** In all of the above, if F is not the name of a database, journal or WAL 3794 ** filename passed into the VFS from the SQLite core and F is not the 3795 ** return value from [sqlite3_db_filename()], then the result is 3796 ** undefined and is likely a memory access violation. 3797 */ 3798 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3799 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3800 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3801 3802 /* 3803 ** CAPI3REF: Database File Corresponding To A Journal 3804 ** 3805 ** ^If X is the name of a rollback or WAL-mode journal file that is 3806 ** passed into the xOpen method of [sqlite3_vfs], then 3807 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3808 ** object that represents the main database file. 3809 ** 3810 ** This routine is intended for use in custom [VFS] implementations 3811 ** only. It is not a general-purpose interface. 3812 ** The argument sqlite3_file_object(X) must be a filename pointer that 3813 ** has been passed into [sqlite3_vfs].xOpen method where the 3814 ** flags parameter to xOpen contains one of the bits 3815 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3816 ** of this routine results in undefined and probably undesirable 3817 ** behavior. 3818 */ 3819 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3820 3821 /* 3822 ** CAPI3REF: Create and Destroy VFS Filenames 3823 ** 3824 ** These interfces are provided for use by [VFS shim] implementations and 3825 ** are not useful outside of that context. 3826 ** 3827 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3828 ** database filename D with corresponding journal file J and WAL file W and 3829 ** with N URI parameters key/values pairs in the array P. The result from 3830 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3831 ** is safe to pass to routines like: 3832 ** <ul> 3833 ** <li> [sqlite3_uri_parameter()], 3834 ** <li> [sqlite3_uri_boolean()], 3835 ** <li> [sqlite3_uri_int64()], 3836 ** <li> [sqlite3_uri_key()], 3837 ** <li> [sqlite3_filename_database()], 3838 ** <li> [sqlite3_filename_journal()], or 3839 ** <li> [sqlite3_filename_wal()]. 3840 ** </ul> 3841 ** If a memory allocation error occurs, sqlite3_create_filename() might 3842 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3843 ** must be released by a corresponding call to sqlite3_free_filename(Y). 3844 ** 3845 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3846 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3847 ** to a key and value for a query parameter. The P parameter may be a NULL 3848 ** pointer if N is zero. None of the 2*N pointers in the P array may be 3849 ** NULL pointers and key pointers should not be empty strings. 3850 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3851 ** be NULL pointers, though they can be empty strings. 3852 ** 3853 ** The sqlite3_free_filename(Y) routine releases a memory allocation 3854 ** previously obtained from sqlite3_create_filename(). Invoking 3855 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3856 ** 3857 ** If the Y parameter to sqlite3_free_filename(Y) is anything other 3858 ** than a NULL pointer or a pointer previously acquired from 3859 ** sqlite3_create_filename(), then bad things such as heap 3860 ** corruption or segfaults may occur. The value Y should not be 3861 ** used again after sqlite3_free_filename(Y) has been called. This means 3862 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3863 ** then the corresponding [sqlite3_module.xClose() method should also be 3864 ** invoked prior to calling sqlite3_free_filename(Y). 3865 */ 3866 SQLITE_API sqlite3_filename sqlite3_create_filename( 3867 const char *zDatabase, 3868 const char *zJournal, 3869 const char *zWal, 3870 int nParam, 3871 const char **azParam 3872 ); 3873 SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3874 3875 /* 3876 ** CAPI3REF: Error Codes And Messages 3877 ** METHOD: sqlite3 3878 ** 3879 ** ^If the most recent sqlite3_* API call associated with 3880 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3881 ** returns the numeric [result code] or [extended result code] for that 3882 ** API call. 3883 ** ^The sqlite3_extended_errcode() 3884 ** interface is the same except that it always returns the 3885 ** [extended result code] even when extended result codes are 3886 ** disabled. 3887 ** 3888 ** The values returned by sqlite3_errcode() and/or 3889 ** sqlite3_extended_errcode() might change with each API call. 3890 ** Except, there are some interfaces that are guaranteed to never 3891 ** change the value of the error code. The error-code preserving 3892 ** interfaces include the following: 3893 ** 3894 ** <ul> 3895 ** <li> sqlite3_errcode() 3896 ** <li> sqlite3_extended_errcode() 3897 ** <li> sqlite3_errmsg() 3898 ** <li> sqlite3_errmsg16() 3899 ** <li> sqlite3_error_offset() 3900 ** </ul> 3901 ** 3902 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3903 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3904 ** ^(Memory to hold the error message string is managed internally. 3905 ** The application does not need to worry about freeing the result. 3906 ** However, the error string might be overwritten or deallocated by 3907 ** subsequent calls to other SQLite interface functions.)^ 3908 ** 3909 ** ^The sqlite3_errstr() interface returns the English-language text 3910 ** that describes the [result code], as UTF-8. 3911 ** ^(Memory to hold the error message string is managed internally 3912 ** and must not be freed by the application)^. 3913 ** 3914 ** ^If the most recent error references a specific token in the input 3915 ** SQL, the sqlite3_error_offset() interface returns the byte offset 3916 ** of the start of that token. ^The byte offset returned by 3917 ** sqlite3_error_offset() assumes that the input SQL is UTF8. 3918 ** ^If the most recent error does not reference a specific token in the input 3919 ** SQL, then the sqlite3_error_offset() function returns -1. 3920 ** 3921 ** When the serialized [threading mode] is in use, it might be the 3922 ** case that a second error occurs on a separate thread in between 3923 ** the time of the first error and the call to these interfaces. 3924 ** When that happens, the second error will be reported since these 3925 ** interfaces always report the most recent result. To avoid 3926 ** this, each thread can obtain exclusive use of the [database connection] D 3927 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3928 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3929 ** all calls to the interfaces listed here are completed. 3930 ** 3931 ** If an interface fails with SQLITE_MISUSE, that means the interface 3932 ** was invoked incorrectly by the application. In that case, the 3933 ** error code and message may or may not be set. 3934 */ 3935 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3936 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3937 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3938 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3939 SQLITE_API const char *sqlite3_errstr(int); 3940 SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3941 3942 /* 3943 ** CAPI3REF: Prepared Statement Object 3944 ** KEYWORDS: {prepared statement} {prepared statements} 3945 ** 3946 ** An instance of this object represents a single SQL statement that 3947 ** has been compiled into binary form and is ready to be evaluated. 3948 ** 3949 ** Think of each SQL statement as a separate computer program. The 3950 ** original SQL text is source code. A prepared statement object 3951 ** is the compiled object code. All SQL must be converted into a 3952 ** prepared statement before it can be run. 3953 ** 3954 ** The life-cycle of a prepared statement object usually goes like this: 3955 ** 3956 ** <ol> 3957 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3958 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3959 ** interfaces. 3960 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3961 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3962 ** to step 2. Do this zero or more times. 3963 ** <li> Destroy the object using [sqlite3_finalize()]. 3964 ** </ol> 3965 */ 3966 typedef struct sqlite3_stmt sqlite3_stmt; 3967 3968 /* 3969 ** CAPI3REF: Run-time Limits 3970 ** METHOD: sqlite3 3971 ** 3972 ** ^(This interface allows the size of various constructs to be limited 3973 ** on a connection by connection basis. The first parameter is the 3974 ** [database connection] whose limit is to be set or queried. The 3975 ** second parameter is one of the [limit categories] that define a 3976 ** class of constructs to be size limited. The third parameter is the 3977 ** new limit for that construct.)^ 3978 ** 3979 ** ^If the new limit is a negative number, the limit is unchanged. 3980 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3981 ** [limits | hard upper bound] 3982 ** set at compile-time by a C preprocessor macro called 3983 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3984 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3985 ** ^Attempts to increase a limit above its hard upper bound are 3986 ** silently truncated to the hard upper bound. 3987 ** 3988 ** ^Regardless of whether or not the limit was changed, the 3989 ** [sqlite3_limit()] interface returns the prior value of the limit. 3990 ** ^Hence, to find the current value of a limit without changing it, 3991 ** simply invoke this interface with the third parameter set to -1. 3992 ** 3993 ** Run-time limits are intended for use in applications that manage 3994 ** both their own internal database and also databases that are controlled 3995 ** by untrusted external sources. An example application might be a 3996 ** web browser that has its own databases for storing history and 3997 ** separate databases controlled by JavaScript applications downloaded 3998 ** off the Internet. The internal databases can be given the 3999 ** large, default limits. Databases managed by external sources can 4000 ** be given much smaller limits designed to prevent a denial of service 4001 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 4002 ** interface to further control untrusted SQL. The size of the database 4003 ** created by an untrusted script can be contained using the 4004 ** [max_page_count] [PRAGMA]. 4005 ** 4006 ** New run-time limit categories may be added in future releases. 4007 */ 4008 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 4009 4010 /* 4011 ** CAPI3REF: Run-Time Limit Categories 4012 ** KEYWORDS: {limit category} {*limit categories} 4013 ** 4014 ** These constants define various performance limits 4015 ** that can be lowered at run-time using [sqlite3_limit()]. 4016 ** The synopsis of the meanings of the various limits is shown below. 4017 ** Additional information is available at [limits | Limits in SQLite]. 4018 ** 4019 ** <dl> 4020 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4021 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4022 ** 4023 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4024 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4025 ** 4026 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4027 ** <dd>The maximum number of columns in a table definition or in the 4028 ** result set of a [SELECT] or the maximum number of columns in an index 4029 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 4030 ** 4031 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4032 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4033 ** 4034 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4035 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4036 ** 4037 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4038 ** <dd>The maximum number of instructions in a virtual machine program 4039 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4040 ** the equivalent tries to allocate space for more than this many opcodes 4041 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4042 ** 4043 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4044 ** <dd>The maximum number of arguments on a function.</dd>)^ 4045 ** 4046 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4047 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4048 ** 4049 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4050 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4051 ** <dd>The maximum length of the pattern argument to the [LIKE] or 4052 ** [GLOB] operators.</dd>)^ 4053 ** 4054 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4055 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4056 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4057 ** 4058 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4059 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 4060 ** 4061 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4062 ** <dd>The maximum number of auxiliary worker threads that a single 4063 ** [prepared statement] may start.</dd>)^ 4064 ** </dl> 4065 */ 4066 #define SQLITE_LIMIT_LENGTH 0 4067 #define SQLITE_LIMIT_SQL_LENGTH 1 4068 #define SQLITE_LIMIT_COLUMN 2 4069 #define SQLITE_LIMIT_EXPR_DEPTH 3 4070 #define SQLITE_LIMIT_COMPOUND_SELECT 4 4071 #define SQLITE_LIMIT_VDBE_OP 5 4072 #define SQLITE_LIMIT_FUNCTION_ARG 6 4073 #define SQLITE_LIMIT_ATTACHED 7 4074 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4075 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 4076 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 4077 #define SQLITE_LIMIT_WORKER_THREADS 11 4078 4079 /* 4080 ** CAPI3REF: Prepare Flags 4081 ** 4082 ** These constants define various flags that can be passed into 4083 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4084 ** [sqlite3_prepare16_v3()] interfaces. 4085 ** 4086 ** New flags may be added in future releases of SQLite. 4087 ** 4088 ** <dl> 4089 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4090 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4091 ** that the prepared statement will be retained for a long time and 4092 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4093 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4094 ** be used just once or at most a few times and then destroyed using 4095 ** [sqlite3_finalize()] relatively soon. The current implementation acts 4096 ** on this hint by avoiding the use of [lookaside memory] so as not to 4097 ** deplete the limited store of lookaside memory. Future versions of 4098 ** SQLite may act on this hint differently. 4099 ** 4100 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4101 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4102 ** to be required for any prepared statement that wanted to use the 4103 ** [sqlite3_normalized_sql()] interface. However, the 4104 ** [sqlite3_normalized_sql()] interface is now available to all 4105 ** prepared statements, regardless of whether or not they use this 4106 ** flag. 4107 ** 4108 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4109 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4110 ** to return an error (error code SQLITE_ERROR) if the statement uses 4111 ** any virtual tables. 4112 ** </dl> 4113 */ 4114 #define SQLITE_PREPARE_PERSISTENT 0x01 4115 #define SQLITE_PREPARE_NORMALIZE 0x02 4116 #define SQLITE_PREPARE_NO_VTAB 0x04 4117 4118 /* 4119 ** CAPI3REF: Compiling An SQL Statement 4120 ** KEYWORDS: {SQL statement compiler} 4121 ** METHOD: sqlite3 4122 ** CONSTRUCTOR: sqlite3_stmt 4123 ** 4124 ** To execute an SQL statement, it must first be compiled into a byte-code 4125 ** program using one of these routines. Or, in other words, these routines 4126 ** are constructors for the [prepared statement] object. 4127 ** 4128 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 4129 ** [sqlite3_prepare()] interface is legacy and should be avoided. 4130 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4131 ** for special purposes. 4132 ** 4133 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 4134 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 4135 ** as a convenience. The UTF-16 interfaces work by converting the 4136 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4137 ** 4138 ** The first argument, "db", is a [database connection] obtained from a 4139 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4140 ** [sqlite3_open16()]. The database connection must not have been closed. 4141 ** 4142 ** The second argument, "zSql", is the statement to be compiled, encoded 4143 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4144 ** and sqlite3_prepare_v3() 4145 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4146 ** and sqlite3_prepare16_v3() use UTF-16. 4147 ** 4148 ** ^If the nByte argument is negative, then zSql is read up to the 4149 ** first zero terminator. ^If nByte is positive, then it is the 4150 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 4151 ** statement is generated. 4152 ** If the caller knows that the supplied string is nul-terminated, then 4153 ** there is a small performance advantage to passing an nByte parameter that 4154 ** is the number of bytes in the input string <i>including</i> 4155 ** the nul-terminator. 4156 ** 4157 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4158 ** past the end of the first SQL statement in zSql. These routines only 4159 ** compile the first statement in zSql, so *pzTail is left pointing to 4160 ** what remains uncompiled. 4161 ** 4162 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4163 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4164 ** to NULL. ^If the input text contains no SQL (if the input is an empty 4165 ** string or a comment) then *ppStmt is set to NULL. 4166 ** The calling procedure is responsible for deleting the compiled 4167 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 4168 ** ppStmt may not be NULL. 4169 ** 4170 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4171 ** otherwise an [error code] is returned. 4172 ** 4173 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4174 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4175 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4176 ** are retained for backwards compatibility, but their use is discouraged. 4177 ** ^In the "vX" interfaces, the prepared statement 4178 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 4179 ** original SQL text. This causes the [sqlite3_step()] interface to 4180 ** behave differently in three ways: 4181 ** 4182 ** <ol> 4183 ** <li> 4184 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4185 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 4186 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4187 ** retries will occur before sqlite3_step() gives up and returns an error. 4188 ** </li> 4189 ** 4190 ** <li> 4191 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4192 ** [error codes] or [extended error codes]. ^The legacy behavior was that 4193 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4194 ** and the application would have to make a second call to [sqlite3_reset()] 4195 ** in order to find the underlying cause of the problem. With the "v2" prepare 4196 ** interfaces, the underlying reason for the error is returned immediately. 4197 ** </li> 4198 ** 4199 ** <li> 4200 ** ^If the specific value bound to a [parameter | host parameter] in the 4201 ** WHERE clause might influence the choice of query plan for a statement, 4202 ** then the statement will be automatically recompiled, as if there had been 4203 ** a schema change, on the first [sqlite3_step()] call following any change 4204 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 4205 ** ^The specific value of a WHERE-clause [parameter] might influence the 4206 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 4207 ** or [GLOB] operator or if the parameter is compared to an indexed column 4208 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4209 ** </li> 4210 ** </ol> 4211 ** 4212 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4213 ** the extra prepFlags parameter, which is a bit array consisting of zero or 4214 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4215 ** sqlite3_prepare_v2() interface works exactly the same as 4216 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 4217 */ 4218 SQLITE_API int sqlite3_prepare( 4219 sqlite3 *db, /* Database handle */ 4220 const char *zSql, /* SQL statement, UTF-8 encoded */ 4221 int nByte, /* Maximum length of zSql in bytes. */ 4222 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4223 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4224 ); 4225 SQLITE_API int sqlite3_prepare_v2( 4226 sqlite3 *db, /* Database handle */ 4227 const char *zSql, /* SQL statement, UTF-8 encoded */ 4228 int nByte, /* Maximum length of zSql in bytes. */ 4229 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4230 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4231 ); 4232 SQLITE_API int sqlite3_prepare_v3( 4233 sqlite3 *db, /* Database handle */ 4234 const char *zSql, /* SQL statement, UTF-8 encoded */ 4235 int nByte, /* Maximum length of zSql in bytes. */ 4236 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4237 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4238 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4239 ); 4240 SQLITE_API int sqlite3_prepare16( 4241 sqlite3 *db, /* Database handle */ 4242 const void *zSql, /* SQL statement, UTF-16 encoded */ 4243 int nByte, /* Maximum length of zSql in bytes. */ 4244 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4245 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4246 ); 4247 SQLITE_API int sqlite3_prepare16_v2( 4248 sqlite3 *db, /* Database handle */ 4249 const void *zSql, /* SQL statement, UTF-16 encoded */ 4250 int nByte, /* Maximum length of zSql in bytes. */ 4251 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4252 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4253 ); 4254 SQLITE_API int sqlite3_prepare16_v3( 4255 sqlite3 *db, /* Database handle */ 4256 const void *zSql, /* SQL statement, UTF-16 encoded */ 4257 int nByte, /* Maximum length of zSql in bytes. */ 4258 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4259 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4260 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4261 ); 4262 4263 /* 4264 ** CAPI3REF: Retrieving Statement SQL 4265 ** METHOD: sqlite3_stmt 4266 ** 4267 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4268 ** SQL text used to create [prepared statement] P if P was 4269 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4270 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4271 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4272 ** string containing the SQL text of prepared statement P with 4273 ** [bound parameters] expanded. 4274 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4275 ** string containing the normalized SQL text of prepared statement P. The 4276 ** semantics used to normalize a SQL statement are unspecified and subject 4277 ** to change. At a minimum, literal values will be replaced with suitable 4278 ** placeholders. 4279 ** 4280 ** ^(For example, if a prepared statement is created using the SQL 4281 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4282 ** and parameter :xyz is unbound, then sqlite3_sql() will return 4283 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4284 ** will return "SELECT 2345,NULL".)^ 4285 ** 4286 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4287 ** is available to hold the result, or if the result would exceed the 4288 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4289 ** 4290 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4291 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4292 ** option causes sqlite3_expanded_sql() to always return NULL. 4293 ** 4294 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4295 ** are managed by SQLite and are automatically freed when the prepared 4296 ** statement is finalized. 4297 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4298 ** is obtained from [sqlite3_malloc()] and must be freed by the application 4299 ** by passing it to [sqlite3_free()]. 4300 ** 4301 ** ^The sqlite3_normalized_sql() interface is only available if 4302 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4303 */ 4304 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4305 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4306 #ifdef SQLITE_ENABLE_NORMALIZE 4307 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4308 #endif 4309 4310 /* 4311 ** CAPI3REF: Determine If An SQL Statement Writes The Database 4312 ** METHOD: sqlite3_stmt 4313 ** 4314 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4315 ** and only if the [prepared statement] X makes no direct changes to 4316 ** the content of the database file. 4317 ** 4318 ** Note that [application-defined SQL functions] or 4319 ** [virtual tables] might change the database indirectly as a side effect. 4320 ** ^(For example, if an application defines a function "eval()" that 4321 ** calls [sqlite3_exec()], then the following SQL statement would 4322 ** change the database file through side-effects: 4323 ** 4324 ** <blockquote><pre> 4325 ** SELECT eval('DELETE FROM t1') FROM t2; 4326 ** </pre></blockquote> 4327 ** 4328 ** But because the [SELECT] statement does not change the database file 4329 ** directly, sqlite3_stmt_readonly() would still return true.)^ 4330 ** 4331 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4332 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4333 ** since the statements themselves do not actually modify the database but 4334 ** rather they control the timing of when other statements modify the 4335 ** database. ^The [ATTACH] and [DETACH] statements also cause 4336 ** sqlite3_stmt_readonly() to return true since, while those statements 4337 ** change the configuration of a database connection, they do not make 4338 ** changes to the content of the database files on disk. 4339 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4340 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4341 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4342 ** sqlite3_stmt_readonly() returns false for those commands. 4343 ** 4344 ** ^This routine returns false if there is any possibility that the 4345 ** statement might change the database file. ^A false return does 4346 ** not guarantee that the statement will change the database file. 4347 ** ^For example, an UPDATE statement might have a WHERE clause that 4348 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4349 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4350 ** read-only no-op if the table already exists, but 4351 ** sqlite3_stmt_readonly() still returns false for such a statement. 4352 ** 4353 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4354 ** statement, then sqlite3_stmt_readonly(X) returns the same value as 4355 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4356 */ 4357 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4358 4359 /* 4360 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4361 ** METHOD: sqlite3_stmt 4362 ** 4363 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4364 ** prepared statement S is an EXPLAIN statement, or 2 if the 4365 ** statement S is an EXPLAIN QUERY PLAN. 4366 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4367 ** an ordinary statement or a NULL pointer. 4368 */ 4369 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4370 4371 /* 4372 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4373 ** METHOD: sqlite3_stmt 4374 ** 4375 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4376 ** [prepared statement] S has been stepped at least once using 4377 ** [sqlite3_step(S)] but has neither run to completion (returned 4378 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4379 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4380 ** interface returns false if S is a NULL pointer. If S is not a 4381 ** NULL pointer and is not a pointer to a valid [prepared statement] 4382 ** object, then the behavior is undefined and probably undesirable. 4383 ** 4384 ** This interface can be used in combination [sqlite3_next_stmt()] 4385 ** to locate all prepared statements associated with a database 4386 ** connection that are in need of being reset. This can be used, 4387 ** for example, in diagnostic routines to search for prepared 4388 ** statements that are holding a transaction open. 4389 */ 4390 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4391 4392 /* 4393 ** CAPI3REF: Dynamically Typed Value Object 4394 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4395 ** 4396 ** SQLite uses the sqlite3_value object to represent all values 4397 ** that can be stored in a database table. SQLite uses dynamic typing 4398 ** for the values it stores. ^Values stored in sqlite3_value objects 4399 ** can be integers, floating point values, strings, BLOBs, or NULL. 4400 ** 4401 ** An sqlite3_value object may be either "protected" or "unprotected". 4402 ** Some interfaces require a protected sqlite3_value. Other interfaces 4403 ** will accept either a protected or an unprotected sqlite3_value. 4404 ** Every interface that accepts sqlite3_value arguments specifies 4405 ** whether or not it requires a protected sqlite3_value. The 4406 ** [sqlite3_value_dup()] interface can be used to construct a new 4407 ** protected sqlite3_value from an unprotected sqlite3_value. 4408 ** 4409 ** The terms "protected" and "unprotected" refer to whether or not 4410 ** a mutex is held. An internal mutex is held for a protected 4411 ** sqlite3_value object but no mutex is held for an unprotected 4412 ** sqlite3_value object. If SQLite is compiled to be single-threaded 4413 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4414 ** or if SQLite is run in one of reduced mutex modes 4415 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4416 ** then there is no distinction between protected and unprotected 4417 ** sqlite3_value objects and they can be used interchangeably. However, 4418 ** for maximum code portability it is recommended that applications 4419 ** still make the distinction between protected and unprotected 4420 ** sqlite3_value objects even when not strictly required. 4421 ** 4422 ** ^The sqlite3_value objects that are passed as parameters into the 4423 ** implementation of [application-defined SQL functions] are protected. 4424 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4425 ** are protected. 4426 ** ^The sqlite3_value object returned by 4427 ** [sqlite3_column_value()] is unprotected. 4428 ** Unprotected sqlite3_value objects may only be used as arguments 4429 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4430 ** [sqlite3_value_dup()]. 4431 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 4432 ** interfaces require protected sqlite3_value objects. 4433 */ 4434 typedef struct sqlite3_value sqlite3_value; 4435 4436 /* 4437 ** CAPI3REF: SQL Function Context Object 4438 ** 4439 ** The context in which an SQL function executes is stored in an 4440 ** sqlite3_context object. ^A pointer to an sqlite3_context object 4441 ** is always first parameter to [application-defined SQL functions]. 4442 ** The application-defined SQL function implementation will pass this 4443 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4444 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4445 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4446 ** and/or [sqlite3_set_auxdata()]. 4447 */ 4448 typedef struct sqlite3_context sqlite3_context; 4449 4450 /* 4451 ** CAPI3REF: Binding Values To Prepared Statements 4452 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4453 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4454 ** METHOD: sqlite3_stmt 4455 ** 4456 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4457 ** literals may be replaced by a [parameter] that matches one of following 4458 ** templates: 4459 ** 4460 ** <ul> 4461 ** <li> ? 4462 ** <li> ?NNN 4463 ** <li> :VVV 4464 ** <li> @VVV 4465 ** <li> $VVV 4466 ** </ul> 4467 ** 4468 ** In the templates above, NNN represents an integer literal, 4469 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 4470 ** parameters (also called "host parameter names" or "SQL parameters") 4471 ** can be set using the sqlite3_bind_*() routines defined here. 4472 ** 4473 ** ^The first argument to the sqlite3_bind_*() routines is always 4474 ** a pointer to the [sqlite3_stmt] object returned from 4475 ** [sqlite3_prepare_v2()] or its variants. 4476 ** 4477 ** ^The second argument is the index of the SQL parameter to be set. 4478 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 4479 ** SQL parameter is used more than once, second and subsequent 4480 ** occurrences have the same index as the first occurrence. 4481 ** ^The index for named parameters can be looked up using the 4482 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 4483 ** for "?NNN" parameters is the value of NNN. 4484 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 4485 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4486 ** 4487 ** ^The third argument is the value to bind to the parameter. 4488 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4489 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4490 ** is ignored and the end result is the same as sqlite3_bind_null(). 4491 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4492 ** it should be a pointer to well-formed UTF8 text. 4493 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4494 ** it should be a pointer to well-formed UTF16 text. 4495 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4496 ** it should be a pointer to a well-formed unicode string that is 4497 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4498 ** otherwise. 4499 ** 4500 ** [[byte-order determination rules]] ^The byte-order of 4501 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4502 ** found in first character, which is removed, or in the absence of a BOM 4503 ** the byte order is the native byte order of the host 4504 ** machine for sqlite3_bind_text16() or the byte order specified in 4505 ** the 6th parameter for sqlite3_bind_text64().)^ 4506 ** ^If UTF16 input text contains invalid unicode 4507 ** characters, then SQLite might change those invalid characters 4508 ** into the unicode replacement character: U+FFFD. 4509 ** 4510 ** ^(In those routines that have a fourth argument, its value is the 4511 ** number of bytes in the parameter. To be clear: the value is the 4512 ** number of <u>bytes</u> in the value, not the number of characters.)^ 4513 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4514 ** is negative, then the length of the string is 4515 ** the number of bytes up to the first zero terminator. 4516 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 4517 ** the behavior is undefined. 4518 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4519 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4520 ** that parameter must be the byte offset 4521 ** where the NUL terminator would occur assuming the string were NUL 4522 ** terminated. If any NUL characters occurs at byte offsets less than 4523 ** the value of the fourth parameter then the resulting string value will 4524 ** contain embedded NULs. The result of expressions involving strings 4525 ** with embedded NULs is undefined. 4526 ** 4527 ** ^The fifth argument to the BLOB and string binding interfaces controls 4528 ** or indicates the lifetime of the object referenced by the third parameter. 4529 ** These three options exist: 4530 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4531 ** with it may be passed. ^It is called to dispose of the BLOB or string even 4532 ** if the call to the bind API fails, except the destructor is not called if 4533 ** the third parameter is a NULL pointer or the fourth parameter is negative. 4534 ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4535 ** the application remains responsible for disposing of the object. ^In this 4536 ** case, the object and the provided pointer to it must remain valid until 4537 ** either the prepared statement is finalized or the same SQL parameter is 4538 ** bound to something else, whichever occurs sooner. 4539 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4540 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4541 ** object and pointer to it must remain valid until then. ^SQLite will then 4542 ** manage the lifetime of its private copy. 4543 ** 4544 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4545 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4546 ** to specify the encoding of the text in the third parameter. If 4547 ** the sixth argument to sqlite3_bind_text64() is not one of the 4548 ** allowed values shown above, or if the text encoding is different 4549 ** from the encoding specified by the sixth parameter, then the behavior 4550 ** is undefined. 4551 ** 4552 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4553 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4554 ** (just an integer to hold its size) while it is being processed. 4555 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4556 ** content is later written using 4557 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4558 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4559 ** 4560 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4561 ** [prepared statement] S to have an SQL value of NULL, but to also be 4562 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4563 ** a pointer to a destructor function for P. ^SQLite will invoke the 4564 ** destructor D with a single argument of P when it is finished using 4565 ** P. The T parameter should be a static string, preferably a string 4566 ** literal. The sqlite3_bind_pointer() routine is part of the 4567 ** [pointer passing interface] added for SQLite 3.20.0. 4568 ** 4569 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4570 ** for the [prepared statement] or with a prepared statement for which 4571 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4572 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4573 ** routine is passed a [prepared statement] that has been finalized, the 4574 ** result is undefined and probably harmful. 4575 ** 4576 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4577 ** ^Unbound parameters are interpreted as NULL. 4578 ** 4579 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4580 ** [error code] if anything goes wrong. 4581 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4582 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4583 ** [SQLITE_MAX_LENGTH]. 4584 ** ^[SQLITE_RANGE] is returned if the parameter 4585 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4586 ** 4587 ** See also: [sqlite3_bind_parameter_count()], 4588 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4589 */ 4590 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4591 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4592 void(*)(void*)); 4593 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4594 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4595 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4596 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4597 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4598 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4599 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4600 void(*)(void*), unsigned char encoding); 4601 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4602 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4603 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4604 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4605 4606 /* 4607 ** CAPI3REF: Number Of SQL Parameters 4608 ** METHOD: sqlite3_stmt 4609 ** 4610 ** ^This routine can be used to find the number of [SQL parameters] 4611 ** in a [prepared statement]. SQL parameters are tokens of the 4612 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4613 ** placeholders for values that are [sqlite3_bind_blob | bound] 4614 ** to the parameters at a later time. 4615 ** 4616 ** ^(This routine actually returns the index of the largest (rightmost) 4617 ** parameter. For all forms except ?NNN, this will correspond to the 4618 ** number of unique parameters. If parameters of the ?NNN form are used, 4619 ** there may be gaps in the list.)^ 4620 ** 4621 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4622 ** [sqlite3_bind_parameter_name()], and 4623 ** [sqlite3_bind_parameter_index()]. 4624 */ 4625 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4626 4627 /* 4628 ** CAPI3REF: Name Of A Host Parameter 4629 ** METHOD: sqlite3_stmt 4630 ** 4631 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4632 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4633 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4634 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4635 ** respectively. 4636 ** In other words, the initial ":" or "$" or "@" or "?" 4637 ** is included as part of the name.)^ 4638 ** ^Parameters of the form "?" without a following integer have no name 4639 ** and are referred to as "nameless" or "anonymous parameters". 4640 ** 4641 ** ^The first host parameter has an index of 1, not 0. 4642 ** 4643 ** ^If the value N is out of range or if the N-th parameter is 4644 ** nameless, then NULL is returned. ^The returned string is 4645 ** always in UTF-8 encoding even if the named parameter was 4646 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4647 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4648 ** 4649 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4650 ** [sqlite3_bind_parameter_count()], and 4651 ** [sqlite3_bind_parameter_index()]. 4652 */ 4653 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4654 4655 /* 4656 ** CAPI3REF: Index Of A Parameter With A Given Name 4657 ** METHOD: sqlite3_stmt 4658 ** 4659 ** ^Return the index of an SQL parameter given its name. ^The 4660 ** index value returned is suitable for use as the second 4661 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4662 ** is returned if no matching parameter is found. ^The parameter 4663 ** name must be given in UTF-8 even if the original statement 4664 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4665 ** [sqlite3_prepare16_v3()]. 4666 ** 4667 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4668 ** [sqlite3_bind_parameter_count()], and 4669 ** [sqlite3_bind_parameter_name()]. 4670 */ 4671 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4672 4673 /* 4674 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4675 ** METHOD: sqlite3_stmt 4676 ** 4677 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4678 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4679 ** ^Use this routine to reset all host parameters to NULL. 4680 */ 4681 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4682 4683 /* 4684 ** CAPI3REF: Number Of Columns In A Result Set 4685 ** METHOD: sqlite3_stmt 4686 ** 4687 ** ^Return the number of columns in the result set returned by the 4688 ** [prepared statement]. ^If this routine returns 0, that means the 4689 ** [prepared statement] returns no data (for example an [UPDATE]). 4690 ** ^However, just because this routine returns a positive number does not 4691 ** mean that one or more rows of data will be returned. ^A SELECT statement 4692 ** will always have a positive sqlite3_column_count() but depending on the 4693 ** WHERE clause constraints and the table content, it might return no rows. 4694 ** 4695 ** See also: [sqlite3_data_count()] 4696 */ 4697 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4698 4699 /* 4700 ** CAPI3REF: Column Names In A Result Set 4701 ** METHOD: sqlite3_stmt 4702 ** 4703 ** ^These routines return the name assigned to a particular column 4704 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4705 ** interface returns a pointer to a zero-terminated UTF-8 string 4706 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4707 ** UTF-16 string. ^The first parameter is the [prepared statement] 4708 ** that implements the [SELECT] statement. ^The second parameter is the 4709 ** column number. ^The leftmost column is number 0. 4710 ** 4711 ** ^The returned string pointer is valid until either the [prepared statement] 4712 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4713 ** reprepared by the first call to [sqlite3_step()] for a particular run 4714 ** or until the next call to 4715 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4716 ** 4717 ** ^If sqlite3_malloc() fails during the processing of either routine 4718 ** (for example during a conversion from UTF-8 to UTF-16) then a 4719 ** NULL pointer is returned. 4720 ** 4721 ** ^The name of a result column is the value of the "AS" clause for 4722 ** that column, if there is an AS clause. If there is no AS clause 4723 ** then the name of the column is unspecified and may change from 4724 ** one release of SQLite to the next. 4725 */ 4726 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4727 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4728 4729 /* 4730 ** CAPI3REF: Source Of Data In A Query Result 4731 ** METHOD: sqlite3_stmt 4732 ** 4733 ** ^These routines provide a means to determine the database, table, and 4734 ** table column that is the origin of a particular result column in 4735 ** [SELECT] statement. 4736 ** ^The name of the database or table or column can be returned as 4737 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4738 ** the database name, the _table_ routines return the table name, and 4739 ** the origin_ routines return the column name. 4740 ** ^The returned string is valid until the [prepared statement] is destroyed 4741 ** using [sqlite3_finalize()] or until the statement is automatically 4742 ** reprepared by the first call to [sqlite3_step()] for a particular run 4743 ** or until the same information is requested 4744 ** again in a different encoding. 4745 ** 4746 ** ^The names returned are the original un-aliased names of the 4747 ** database, table, and column. 4748 ** 4749 ** ^The first argument to these interfaces is a [prepared statement]. 4750 ** ^These functions return information about the Nth result column returned by 4751 ** the statement, where N is the second function argument. 4752 ** ^The left-most column is column 0 for these routines. 4753 ** 4754 ** ^If the Nth column returned by the statement is an expression or 4755 ** subquery and is not a column value, then all of these functions return 4756 ** NULL. ^These routines might also return NULL if a memory allocation error 4757 ** occurs. ^Otherwise, they return the name of the attached database, table, 4758 ** or column that query result column was extracted from. 4759 ** 4760 ** ^As with all other SQLite APIs, those whose names end with "16" return 4761 ** UTF-16 encoded strings and the other functions return UTF-8. 4762 ** 4763 ** ^These APIs are only available if the library was compiled with the 4764 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4765 ** 4766 ** If two or more threads call one or more 4767 ** [sqlite3_column_database_name | column metadata interfaces] 4768 ** for the same [prepared statement] and result column 4769 ** at the same time then the results are undefined. 4770 */ 4771 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4772 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4773 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4774 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4775 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4776 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4777 4778 /* 4779 ** CAPI3REF: Declared Datatype Of A Query Result 4780 ** METHOD: sqlite3_stmt 4781 ** 4782 ** ^(The first parameter is a [prepared statement]. 4783 ** If this statement is a [SELECT] statement and the Nth column of the 4784 ** returned result set of that [SELECT] is a table column (not an 4785 ** expression or subquery) then the declared type of the table 4786 ** column is returned.)^ ^If the Nth column of the result set is an 4787 ** expression or subquery, then a NULL pointer is returned. 4788 ** ^The returned string is always UTF-8 encoded. 4789 ** 4790 ** ^(For example, given the database schema: 4791 ** 4792 ** CREATE TABLE t1(c1 VARIANT); 4793 ** 4794 ** and the following statement to be compiled: 4795 ** 4796 ** SELECT c1 + 1, c1 FROM t1; 4797 ** 4798 ** this routine would return the string "VARIANT" for the second result 4799 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4800 ** 4801 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4802 ** is declared to contain a particular type does not mean that the 4803 ** data stored in that column is of the declared type. SQLite is 4804 ** strongly typed, but the typing is dynamic not static. ^Type 4805 ** is associated with individual values, not with the containers 4806 ** used to hold those values. 4807 */ 4808 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4809 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4810 4811 /* 4812 ** CAPI3REF: Evaluate An SQL Statement 4813 ** METHOD: sqlite3_stmt 4814 ** 4815 ** After a [prepared statement] has been prepared using any of 4816 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4817 ** or [sqlite3_prepare16_v3()] or one of the legacy 4818 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4819 ** must be called one or more times to evaluate the statement. 4820 ** 4821 ** The details of the behavior of the sqlite3_step() interface depend 4822 ** on whether the statement was prepared using the newer "vX" interfaces 4823 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4824 ** [sqlite3_prepare16_v2()] or the older legacy 4825 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4826 ** new "vX" interface is recommended for new applications but the legacy 4827 ** interface will continue to be supported. 4828 ** 4829 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4830 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4831 ** ^With the "v2" interface, any of the other [result codes] or 4832 ** [extended result codes] might be returned as well. 4833 ** 4834 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4835 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4836 ** or occurs outside of an explicit transaction, then you can retry the 4837 ** statement. If the statement is not a [COMMIT] and occurs within an 4838 ** explicit transaction then you should rollback the transaction before 4839 ** continuing. 4840 ** 4841 ** ^[SQLITE_DONE] means that the statement has finished executing 4842 ** successfully. sqlite3_step() should not be called again on this virtual 4843 ** machine without first calling [sqlite3_reset()] to reset the virtual 4844 ** machine back to its initial state. 4845 ** 4846 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4847 ** is returned each time a new row of data is ready for processing by the 4848 ** caller. The values may be accessed using the [column access functions]. 4849 ** sqlite3_step() is called again to retrieve the next row of data. 4850 ** 4851 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4852 ** violation) has occurred. sqlite3_step() should not be called again on 4853 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4854 ** ^With the legacy interface, a more specific error code (for example, 4855 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4856 ** can be obtained by calling [sqlite3_reset()] on the 4857 ** [prepared statement]. ^In the "v2" interface, 4858 ** the more specific error code is returned directly by sqlite3_step(). 4859 ** 4860 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4861 ** Perhaps it was called on a [prepared statement] that has 4862 ** already been [sqlite3_finalize | finalized] or on one that had 4863 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4864 ** be the case that the same database connection is being used by two or 4865 ** more threads at the same moment in time. 4866 ** 4867 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4868 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4869 ** other than [SQLITE_ROW] before any subsequent invocation of 4870 ** sqlite3_step(). Failure to reset the prepared statement using 4871 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4872 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4873 ** sqlite3_step() began 4874 ** calling [sqlite3_reset()] automatically in this circumstance rather 4875 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4876 ** break because any application that ever receives an SQLITE_MISUSE error 4877 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4878 ** can be used to restore the legacy behavior. 4879 ** 4880 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4881 ** API always returns a generic error code, [SQLITE_ERROR], following any 4882 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4883 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4884 ** specific [error codes] that better describes the error. 4885 ** We admit that this is a goofy design. The problem has been fixed 4886 ** with the "v2" interface. If you prepare all of your SQL statements 4887 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4888 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4889 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4890 ** then the more specific [error codes] are returned directly 4891 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4892 */ 4893 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4894 4895 /* 4896 ** CAPI3REF: Number of columns in a result set 4897 ** METHOD: sqlite3_stmt 4898 ** 4899 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4900 ** current row of the result set of [prepared statement] P. 4901 ** ^If prepared statement P does not have results ready to return 4902 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4903 ** interfaces) then sqlite3_data_count(P) returns 0. 4904 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4905 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4906 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4907 ** will return non-zero if previous call to [sqlite3_step](P) returned 4908 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4909 ** where it always returns zero since each step of that multi-step 4910 ** pragma returns 0 columns of data. 4911 ** 4912 ** See also: [sqlite3_column_count()] 4913 */ 4914 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4915 4916 /* 4917 ** CAPI3REF: Fundamental Datatypes 4918 ** KEYWORDS: SQLITE_TEXT 4919 ** 4920 ** ^(Every value in SQLite has one of five fundamental datatypes: 4921 ** 4922 ** <ul> 4923 ** <li> 64-bit signed integer 4924 ** <li> 64-bit IEEE floating point number 4925 ** <li> string 4926 ** <li> BLOB 4927 ** <li> NULL 4928 ** </ul>)^ 4929 ** 4930 ** These constants are codes for each of those types. 4931 ** 4932 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4933 ** for a completely different meaning. Software that links against both 4934 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4935 ** SQLITE_TEXT. 4936 */ 4937 #define SQLITE_INTEGER 1 4938 #define SQLITE_FLOAT 2 4939 #define SQLITE_BLOB 4 4940 #define SQLITE_NULL 5 4941 #ifdef SQLITE_TEXT 4942 # undef SQLITE_TEXT 4943 #else 4944 # define SQLITE_TEXT 3 4945 #endif 4946 #define SQLITE3_TEXT 3 4947 4948 /* 4949 ** CAPI3REF: Result Values From A Query 4950 ** KEYWORDS: {column access functions} 4951 ** METHOD: sqlite3_stmt 4952 ** 4953 ** <b>Summary:</b> 4954 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4955 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4956 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4957 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4958 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4959 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4960 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4961 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4962 ** [sqlite3_value|unprotected sqlite3_value] object. 4963 ** <tr><td> <td> <td> 4964 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4965 ** or a UTF-8 TEXT result in bytes 4966 ** <tr><td><b>sqlite3_column_bytes16 </b> 4967 ** <td>→ <td>Size of UTF-16 4968 ** TEXT in bytes 4969 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4970 ** datatype of the result 4971 ** </table></blockquote> 4972 ** 4973 ** <b>Details:</b> 4974 ** 4975 ** ^These routines return information about a single column of the current 4976 ** result row of a query. ^In every case the first argument is a pointer 4977 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4978 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4979 ** and the second argument is the index of the column for which information 4980 ** should be returned. ^The leftmost column of the result set has the index 0. 4981 ** ^The number of columns in the result can be determined using 4982 ** [sqlite3_column_count()]. 4983 ** 4984 ** If the SQL statement does not currently point to a valid row, or if the 4985 ** column index is out of range, the result is undefined. 4986 ** These routines may only be called when the most recent call to 4987 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4988 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4989 ** If any of these routines are called after [sqlite3_reset()] or 4990 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4991 ** something other than [SQLITE_ROW], the results are undefined. 4992 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4993 ** are called from a different thread while any of these routines 4994 ** are pending, then the results are undefined. 4995 ** 4996 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4997 ** each return the value of a result column in a specific data format. If 4998 ** the result column is not initially in the requested format (for example, 4999 ** if the query returns an integer but the sqlite3_column_text() interface 5000 ** is used to extract the value) then an automatic type conversion is performed. 5001 ** 5002 ** ^The sqlite3_column_type() routine returns the 5003 ** [SQLITE_INTEGER | datatype code] for the initial data type 5004 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 5005 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 5006 ** The return value of sqlite3_column_type() can be used to decide which 5007 ** of the first six interface should be used to extract the column value. 5008 ** The value returned by sqlite3_column_type() is only meaningful if no 5009 ** automatic type conversions have occurred for the value in question. 5010 ** After a type conversion, the result of calling sqlite3_column_type() 5011 ** is undefined, though harmless. Future 5012 ** versions of SQLite may change the behavior of sqlite3_column_type() 5013 ** following a type conversion. 5014 ** 5015 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 5016 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 5017 ** of that BLOB or string. 5018 ** 5019 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5020 ** routine returns the number of bytes in that BLOB or string. 5021 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5022 ** the string to UTF-8 and then returns the number of bytes. 5023 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 5024 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5025 ** the number of bytes in that string. 5026 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5027 ** 5028 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5029 ** routine returns the number of bytes in that BLOB or string. 5030 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5031 ** the string to UTF-16 and then returns the number of bytes. 5032 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5033 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5034 ** the number of bytes in that string. 5035 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5036 ** 5037 ** ^The values returned by [sqlite3_column_bytes()] and 5038 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5039 ** of the string. ^For clarity: the values returned by 5040 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5041 ** bytes in the string, not the number of characters. 5042 ** 5043 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5044 ** even empty strings, are always zero-terminated. ^The return 5045 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5046 ** 5047 ** ^Strings returned by sqlite3_column_text16() always have the endianness 5048 ** which is native to the platform, regardless of the text encoding set 5049 ** for the database. 5050 ** 5051 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5052 ** [unprotected sqlite3_value] object. In a multithreaded environment, 5053 ** an unprotected sqlite3_value object may only be used safely with 5054 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5055 ** If the [unprotected sqlite3_value] object returned by 5056 ** [sqlite3_column_value()] is used in any other way, including calls 5057 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5058 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5059 ** Hence, the sqlite3_column_value() interface 5060 ** is normally only useful within the implementation of 5061 ** [application-defined SQL functions] or [virtual tables], not within 5062 ** top-level application code. 5063 ** 5064 ** These routines may attempt to convert the datatype of the result. 5065 ** ^For example, if the internal representation is FLOAT and a text result 5066 ** is requested, [sqlite3_snprintf()] is used internally to perform the 5067 ** conversion automatically. ^(The following table details the conversions 5068 ** that are applied: 5069 ** 5070 ** <blockquote> 5071 ** <table border="1"> 5072 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5073 ** 5074 ** <tr><td> NULL <td> INTEGER <td> Result is 0 5075 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5076 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5077 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5078 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5079 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5080 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5081 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5082 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5083 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5084 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5085 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5086 ** <tr><td> TEXT <td> BLOB <td> No change 5087 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5088 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5089 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5090 ** </table> 5091 ** </blockquote>)^ 5092 ** 5093 ** Note that when type conversions occur, pointers returned by prior 5094 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5095 ** sqlite3_column_text16() may be invalidated. 5096 ** Type conversions and pointer invalidations might occur 5097 ** in the following cases: 5098 ** 5099 ** <ul> 5100 ** <li> The initial content is a BLOB and sqlite3_column_text() or 5101 ** sqlite3_column_text16() is called. A zero-terminator might 5102 ** need to be added to the string.</li> 5103 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5104 ** sqlite3_column_text16() is called. The content must be converted 5105 ** to UTF-16.</li> 5106 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5107 ** sqlite3_column_text() is called. The content must be converted 5108 ** to UTF-8.</li> 5109 ** </ul> 5110 ** 5111 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5112 ** not invalidate a prior pointer, though of course the content of the buffer 5113 ** that the prior pointer references will have been modified. Other kinds 5114 ** of conversion are done in place when it is possible, but sometimes they 5115 ** are not possible and in those cases prior pointers are invalidated. 5116 ** 5117 ** The safest policy is to invoke these routines 5118 ** in one of the following ways: 5119 ** 5120 ** <ul> 5121 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5122 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5123 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5124 ** </ul> 5125 ** 5126 ** In other words, you should call sqlite3_column_text(), 5127 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5128 ** into the desired format, then invoke sqlite3_column_bytes() or 5129 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5130 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5131 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5132 ** with calls to sqlite3_column_bytes(). 5133 ** 5134 ** ^The pointers returned are valid until a type conversion occurs as 5135 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5136 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5137 ** and BLOBs is freed automatically. Do not pass the pointers returned 5138 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5139 ** [sqlite3_free()]. 5140 ** 5141 ** As long as the input parameters are correct, these routines will only 5142 ** fail if an out-of-memory error occurs during a format conversion. 5143 ** Only the following subset of interfaces are subject to out-of-memory 5144 ** errors: 5145 ** 5146 ** <ul> 5147 ** <li> sqlite3_column_blob() 5148 ** <li> sqlite3_column_text() 5149 ** <li> sqlite3_column_text16() 5150 ** <li> sqlite3_column_bytes() 5151 ** <li> sqlite3_column_bytes16() 5152 ** </ul> 5153 ** 5154 ** If an out-of-memory error occurs, then the return value from these 5155 ** routines is the same as if the column had contained an SQL NULL value. 5156 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5157 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5158 ** return value is obtained and before any 5159 ** other SQLite interface is called on the same [database connection]. 5160 */ 5161 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5162 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5163 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5164 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5165 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5166 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5167 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5168 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5169 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5170 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5171 5172 /* 5173 ** CAPI3REF: Destroy A Prepared Statement Object 5174 ** DESTRUCTOR: sqlite3_stmt 5175 ** 5176 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5177 ** ^If the most recent evaluation of the statement encountered no errors 5178 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 5179 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5180 ** sqlite3_finalize(S) returns the appropriate [error code] or 5181 ** [extended error code]. 5182 ** 5183 ** ^The sqlite3_finalize(S) routine can be called at any point during 5184 ** the life cycle of [prepared statement] S: 5185 ** before statement S is ever evaluated, after 5186 ** one or more calls to [sqlite3_reset()], or after any call 5187 ** to [sqlite3_step()] regardless of whether or not the statement has 5188 ** completed execution. 5189 ** 5190 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5191 ** 5192 ** The application must finalize every [prepared statement] in order to avoid 5193 ** resource leaks. It is a grievous error for the application to try to use 5194 ** a prepared statement after it has been finalized. Any use of a prepared 5195 ** statement after it has been finalized can result in undefined and 5196 ** undesirable behavior such as segfaults and heap corruption. 5197 */ 5198 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5199 5200 /* 5201 ** CAPI3REF: Reset A Prepared Statement Object 5202 ** METHOD: sqlite3_stmt 5203 ** 5204 ** The sqlite3_reset() function is called to reset a [prepared statement] 5205 ** object back to its initial state, ready to be re-executed. 5206 ** ^Any SQL statement variables that had values bound to them using 5207 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5208 ** Use [sqlite3_clear_bindings()] to reset the bindings. 5209 ** 5210 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5211 ** back to the beginning of its program. 5212 ** 5213 ** ^If the most recent call to [sqlite3_step(S)] for the 5214 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5215 ** or if [sqlite3_step(S)] has never before been called on S, 5216 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5217 ** 5218 ** ^If the most recent call to [sqlite3_step(S)] for the 5219 ** [prepared statement] S indicated an error, then 5220 ** [sqlite3_reset(S)] returns an appropriate [error code]. 5221 ** 5222 ** ^The [sqlite3_reset(S)] interface does not change the values 5223 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5224 */ 5225 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5226 5227 /* 5228 ** CAPI3REF: Create Or Redefine SQL Functions 5229 ** KEYWORDS: {function creation routines} 5230 ** METHOD: sqlite3 5231 ** 5232 ** ^These functions (collectively known as "function creation routines") 5233 ** are used to add SQL functions or aggregates or to redefine the behavior 5234 ** of existing SQL functions or aggregates. The only differences between 5235 ** the three "sqlite3_create_function*" routines are the text encoding 5236 ** expected for the second parameter (the name of the function being 5237 ** created) and the presence or absence of a destructor callback for 5238 ** the application data pointer. Function sqlite3_create_window_function() 5239 ** is similar, but allows the user to supply the extra callback functions 5240 ** needed by [aggregate window functions]. 5241 ** 5242 ** ^The first parameter is the [database connection] to which the SQL 5243 ** function is to be added. ^If an application uses more than one database 5244 ** connection then application-defined SQL functions must be added 5245 ** to each database connection separately. 5246 ** 5247 ** ^The second parameter is the name of the SQL function to be created or 5248 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5249 ** representation, exclusive of the zero-terminator. ^Note that the name 5250 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5251 ** ^Any attempt to create a function with a longer name 5252 ** will result in [SQLITE_MISUSE] being returned. 5253 ** 5254 ** ^The third parameter (nArg) 5255 ** is the number of arguments that the SQL function or 5256 ** aggregate takes. ^If this parameter is -1, then the SQL function or 5257 ** aggregate may take any number of arguments between 0 and the limit 5258 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5259 ** parameter is less than -1 or greater than 127 then the behavior is 5260 ** undefined. 5261 ** 5262 ** ^The fourth parameter, eTextRep, specifies what 5263 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5264 ** its parameters. The application should set this parameter to 5265 ** [SQLITE_UTF16LE] if the function implementation invokes 5266 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5267 ** implementation invokes [sqlite3_value_text16be()] on an input, or 5268 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5269 ** otherwise. ^The same SQL function may be registered multiple times using 5270 ** different preferred text encodings, with different implementations for 5271 ** each encoding. 5272 ** ^When multiple implementations of the same function are available, SQLite 5273 ** will pick the one that involves the least amount of data conversion. 5274 ** 5275 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5276 ** to signal that the function will always return the same result given 5277 ** the same inputs within a single SQL statement. Most SQL functions are 5278 ** deterministic. The built-in [random()] SQL function is an example of a 5279 ** function that is not deterministic. The SQLite query planner is able to 5280 ** perform additional optimizations on deterministic functions, so use 5281 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5282 ** 5283 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5284 ** flag, which if present prevents the function from being invoked from 5285 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5286 ** index expressions, or the WHERE clause of partial indexes. 5287 ** 5288 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5289 ** all application-defined SQL functions that do not need to be 5290 ** used inside of triggers, view, CHECK constraints, or other elements of 5291 ** the database schema. This flags is especially recommended for SQL 5292 ** functions that have side effects or reveal internal application state. 5293 ** Without this flag, an attacker might be able to modify the schema of 5294 ** a database file to include invocations of the function with parameters 5295 ** chosen by the attacker, which the application will then execute when 5296 ** the database file is opened and read. 5297 ** 5298 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5299 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 5300 ** 5301 ** ^The sixth, seventh and eighth parameters passed to the three 5302 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5303 ** pointers to C-language functions that implement the SQL function or 5304 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5305 ** callback only; NULL pointers must be passed as the xStep and xFinal 5306 ** parameters. ^An aggregate SQL function requires an implementation of xStep 5307 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5308 ** SQL function or aggregate, pass NULL pointers for all three function 5309 ** callbacks. 5310 ** 5311 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5312 ** and xInverse) passed to sqlite3_create_window_function are pointers to 5313 ** C-language callbacks that implement the new function. xStep and xFinal 5314 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 5315 ** which case a regular aggregate function is created, or must both be 5316 ** non-NULL, in which case the new function may be used as either an aggregate 5317 ** or aggregate window function. More details regarding the implementation 5318 ** of aggregate window functions are 5319 ** [user-defined window functions|available here]. 5320 ** 5321 ** ^(If the final parameter to sqlite3_create_function_v2() or 5322 ** sqlite3_create_window_function() is not NULL, then it is destructor for 5323 ** the application data pointer. The destructor is invoked when the function 5324 ** is deleted, either by being overloaded or when the database connection 5325 ** closes.)^ ^The destructor is also invoked if the call to 5326 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 5327 ** invoked, it is passed a single argument which is a copy of the application 5328 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5329 ** 5330 ** ^It is permitted to register multiple implementations of the same 5331 ** functions with the same name but with either differing numbers of 5332 ** arguments or differing preferred text encodings. ^SQLite will use 5333 ** the implementation that most closely matches the way in which the 5334 ** SQL function is used. ^A function implementation with a non-negative 5335 ** nArg parameter is a better match than a function implementation with 5336 ** a negative nArg. ^A function where the preferred text encoding 5337 ** matches the database encoding is a better 5338 ** match than a function where the encoding is different. 5339 ** ^A function where the encoding difference is between UTF16le and UTF16be 5340 ** is a closer match than a function where the encoding difference is 5341 ** between UTF8 and UTF16. 5342 ** 5343 ** ^Built-in functions may be overloaded by new application-defined functions. 5344 ** 5345 ** ^An application-defined function is permitted to call other 5346 ** SQLite interfaces. However, such calls must not 5347 ** close the database connection nor finalize or reset the prepared 5348 ** statement in which the function is running. 5349 */ 5350 SQLITE_API int sqlite3_create_function( 5351 sqlite3 *db, 5352 const char *zFunctionName, 5353 int nArg, 5354 int eTextRep, 5355 void *pApp, 5356 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5357 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5358 void (*xFinal)(sqlite3_context*) 5359 ); 5360 SQLITE_API int sqlite3_create_function16( 5361 sqlite3 *db, 5362 const void *zFunctionName, 5363 int nArg, 5364 int eTextRep, 5365 void *pApp, 5366 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5367 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5368 void (*xFinal)(sqlite3_context*) 5369 ); 5370 SQLITE_API int sqlite3_create_function_v2( 5371 sqlite3 *db, 5372 const char *zFunctionName, 5373 int nArg, 5374 int eTextRep, 5375 void *pApp, 5376 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5377 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5378 void (*xFinal)(sqlite3_context*), 5379 void(*xDestroy)(void*) 5380 ); 5381 SQLITE_API int sqlite3_create_window_function( 5382 sqlite3 *db, 5383 const char *zFunctionName, 5384 int nArg, 5385 int eTextRep, 5386 void *pApp, 5387 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5388 void (*xFinal)(sqlite3_context*), 5389 void (*xValue)(sqlite3_context*), 5390 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5391 void(*xDestroy)(void*) 5392 ); 5393 5394 /* 5395 ** CAPI3REF: Text Encodings 5396 ** 5397 ** These constant define integer codes that represent the various 5398 ** text encodings supported by SQLite. 5399 */ 5400 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5401 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5402 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5403 #define SQLITE_UTF16 4 /* Use native byte order */ 5404 #define SQLITE_ANY 5 /* Deprecated */ 5405 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5406 5407 /* 5408 ** CAPI3REF: Function Flags 5409 ** 5410 ** These constants may be ORed together with the 5411 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5412 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5413 ** [sqlite3_create_function_v2()]. 5414 ** 5415 ** <dl> 5416 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5417 ** The SQLITE_DETERMINISTIC flag means that the new function always gives 5418 ** the same output when the input parameters are the same. 5419 ** The [abs|abs() function] is deterministic, for example, but 5420 ** [randomblob|randomblob()] is not. Functions must 5421 ** be deterministic in order to be used in certain contexts such as 5422 ** with the WHERE clause of [partial indexes] or in [generated columns]. 5423 ** SQLite might also optimize deterministic functions by factoring them 5424 ** out of inner loops. 5425 ** </dd> 5426 ** 5427 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5428 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5429 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5430 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5431 ** [expression indexes], [partial indexes], or [generated columns]. 5432 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5433 ** for all [application-defined SQL functions], and especially for functions 5434 ** that have side-effects or that could potentially leak sensitive 5435 ** information. 5436 ** </dd> 5437 ** 5438 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5439 ** The SQLITE_INNOCUOUS flag means that the function is unlikely 5440 ** to cause problems even if misused. An innocuous function should have 5441 ** no side effects and should not depend on any values other than its 5442 ** input parameters. The [abs|abs() function] is an example of an 5443 ** innocuous function. 5444 ** The [load_extension() SQL function] is not innocuous because of its 5445 ** side effects. 5446 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5447 ** exactly the same. The [random|random() function] is an example of a 5448 ** function that is innocuous but not deterministic. 5449 ** <p>Some heightened security settings 5450 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5451 ** disable the use of SQL functions inside views and triggers and in 5452 ** schema structures such as [CHECK constraints], [DEFAULT clauses], 5453 ** [expression indexes], [partial indexes], and [generated columns] unless 5454 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5455 ** are innocuous. Developers are advised to avoid using the 5456 ** SQLITE_INNOCUOUS flag for application-defined functions unless the 5457 ** function has been carefully audited and found to be free of potentially 5458 ** security-adverse side-effects and information-leaks. 5459 ** </dd> 5460 ** 5461 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5462 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5463 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5464 ** Specifying this flag makes no difference for scalar or aggregate user 5465 ** functions. However, if it is not specified for a user-defined window 5466 ** function, then any sub-types belonging to arguments passed to the window 5467 ** function may be discarded before the window function is called (i.e. 5468 ** sqlite3_value_subtype() will always return 0). 5469 ** </dd> 5470 ** </dl> 5471 */ 5472 #define SQLITE_DETERMINISTIC 0x000000800 5473 #define SQLITE_DIRECTONLY 0x000080000 5474 #define SQLITE_SUBTYPE 0x000100000 5475 #define SQLITE_INNOCUOUS 0x000200000 5476 5477 /* 5478 ** CAPI3REF: Deprecated Functions 5479 ** DEPRECATED 5480 ** 5481 ** These functions are [deprecated]. In order to maintain 5482 ** backwards compatibility with older code, these functions continue 5483 ** to be supported. However, new applications should avoid 5484 ** the use of these functions. To encourage programmers to avoid 5485 ** these functions, we will not explain what they do. 5486 */ 5487 #ifndef SQLITE_OMIT_DEPRECATED 5488 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5489 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5490 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5491 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5492 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5493 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5494 void*,sqlite3_int64); 5495 #endif 5496 5497 /* 5498 ** CAPI3REF: Obtaining SQL Values 5499 ** METHOD: sqlite3_value 5500 ** 5501 ** <b>Summary:</b> 5502 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5503 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5504 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5505 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5506 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5507 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5508 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5509 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5510 ** the native byteorder 5511 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5512 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5513 ** <tr><td> <td> <td> 5514 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5515 ** or a UTF-8 TEXT in bytes 5516 ** <tr><td><b>sqlite3_value_bytes16 </b> 5517 ** <td>→ <td>Size of UTF-16 5518 ** TEXT in bytes 5519 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5520 ** datatype of the value 5521 ** <tr><td><b>sqlite3_value_numeric_type </b> 5522 ** <td>→ <td>Best numeric datatype of the value 5523 ** <tr><td><b>sqlite3_value_nochange </b> 5524 ** <td>→ <td>True if the column is unchanged in an UPDATE 5525 ** against a virtual table. 5526 ** <tr><td><b>sqlite3_value_frombind </b> 5527 ** <td>→ <td>True if value originated from a [bound parameter] 5528 ** </table></blockquote> 5529 ** 5530 ** <b>Details:</b> 5531 ** 5532 ** These routines extract type, size, and content information from 5533 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 5534 ** are used to pass parameter information into the functions that 5535 ** implement [application-defined SQL functions] and [virtual tables]. 5536 ** 5537 ** These routines work only with [protected sqlite3_value] objects. 5538 ** Any attempt to use these routines on an [unprotected sqlite3_value] 5539 ** is not threadsafe. 5540 ** 5541 ** ^These routines work just like the corresponding [column access functions] 5542 ** except that these routines take a single [protected sqlite3_value] object 5543 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5544 ** 5545 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5546 ** in the native byte-order of the host machine. ^The 5547 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5548 ** extract UTF-16 strings as big-endian and little-endian respectively. 5549 ** 5550 ** ^If [sqlite3_value] object V was initialized 5551 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5552 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 5553 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5554 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5555 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5556 ** 5557 ** ^(The sqlite3_value_type(V) interface returns the 5558 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5559 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5560 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5561 ** Other interfaces might change the datatype for an sqlite3_value object. 5562 ** For example, if the datatype is initially SQLITE_INTEGER and 5563 ** sqlite3_value_text(V) is called to extract a text value for that 5564 ** integer, then subsequent calls to sqlite3_value_type(V) might return 5565 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5566 ** occurs is undefined and may change from one release of SQLite to the next. 5567 ** 5568 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 5569 ** numeric affinity to the value. This means that an attempt is 5570 ** made to convert the value to an integer or floating point. If 5571 ** such a conversion is possible without loss of information (in other 5572 ** words, if the value is a string that looks like a number) 5573 ** then the conversion is performed. Otherwise no conversion occurs. 5574 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5575 ** 5576 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5577 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current encoding 5578 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5579 ** returns something other than SQLITE_TEXT, then the return value from 5580 ** sqlite3_value_encoding(X) is meaningless. ^Calls to 5581 ** sqlite3_value_text(X), sqlite3_value_text16(X), sqlite3_value_text16be(X), 5582 ** sqlite3_value_text16le(X), sqlite3_value_bytes(X), or 5583 ** sqlite3_value_bytes16(X) might change the encoding of the value X and 5584 ** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5585 ** 5586 ** ^Within the [xUpdate] method of a [virtual table], the 5587 ** sqlite3_value_nochange(X) interface returns true if and only if 5588 ** the column corresponding to X is unchanged by the UPDATE operation 5589 ** that the xUpdate method call was invoked to implement and if 5590 ** and the prior [xColumn] method call that was invoked to extracted 5591 ** the value for that column returned without setting a result (probably 5592 ** because it queried [sqlite3_vtab_nochange()] and found that the column 5593 ** was unchanging). ^Within an [xUpdate] method, any value for which 5594 ** sqlite3_value_nochange(X) is true will in all other respects appear 5595 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5596 ** than within an [xUpdate] method call for an UPDATE statement, then 5597 ** the return value is arbitrary and meaningless. 5598 ** 5599 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5600 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5601 ** interfaces. ^If X comes from an SQL literal value, or a table column, 5602 ** or an expression, then sqlite3_value_frombind(X) returns zero. 5603 ** 5604 ** Please pay particular attention to the fact that the pointer returned 5605 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5606 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5607 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5608 ** or [sqlite3_value_text16()]. 5609 ** 5610 ** These routines must be called from the same thread as 5611 ** the SQL function that supplied the [sqlite3_value*] parameters. 5612 ** 5613 ** As long as the input parameter is correct, these routines can only 5614 ** fail if an out-of-memory error occurs during a format conversion. 5615 ** Only the following subset of interfaces are subject to out-of-memory 5616 ** errors: 5617 ** 5618 ** <ul> 5619 ** <li> sqlite3_value_blob() 5620 ** <li> sqlite3_value_text() 5621 ** <li> sqlite3_value_text16() 5622 ** <li> sqlite3_value_text16le() 5623 ** <li> sqlite3_value_text16be() 5624 ** <li> sqlite3_value_bytes() 5625 ** <li> sqlite3_value_bytes16() 5626 ** </ul> 5627 ** 5628 ** If an out-of-memory error occurs, then the return value from these 5629 ** routines is the same as if the column had contained an SQL NULL value. 5630 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5631 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5632 ** return value is obtained and before any 5633 ** other SQLite interface is called on the same [database connection]. 5634 */ 5635 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5636 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5637 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5638 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5639 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5640 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5641 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5642 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5643 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5644 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5645 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5646 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5647 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5648 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5649 SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5650 SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5651 5652 /* 5653 ** CAPI3REF: Finding The Subtype Of SQL Values 5654 ** METHOD: sqlite3_value 5655 ** 5656 ** The sqlite3_value_subtype(V) function returns the subtype for 5657 ** an [application-defined SQL function] argument V. The subtype 5658 ** information can be used to pass a limited amount of context from 5659 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5660 ** routine to set the subtype for the return value of an SQL function. 5661 */ 5662 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5663 5664 /* 5665 ** CAPI3REF: Copy And Free SQL Values 5666 ** METHOD: sqlite3_value 5667 ** 5668 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5669 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5670 ** is a [protected sqlite3_value] object even if the input is not. 5671 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5672 ** memory allocation fails. ^If V is a [pointer value], then the result 5673 ** of sqlite3_value_dup(V) is a NULL value. 5674 ** 5675 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5676 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5677 ** then sqlite3_value_free(V) is a harmless no-op. 5678 */ 5679 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5680 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5681 5682 /* 5683 ** CAPI3REF: Obtain Aggregate Function Context 5684 ** METHOD: sqlite3_context 5685 ** 5686 ** Implementations of aggregate SQL functions use this 5687 ** routine to allocate memory for storing their state. 5688 ** 5689 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5690 ** for a particular aggregate function, SQLite allocates 5691 ** N bytes of memory, zeroes out that memory, and returns a pointer 5692 ** to the new memory. ^On second and subsequent calls to 5693 ** sqlite3_aggregate_context() for the same aggregate function instance, 5694 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5695 ** called once for each invocation of the xStep callback and then one 5696 ** last time when the xFinal callback is invoked. ^(When no rows match 5697 ** an aggregate query, the xStep() callback of the aggregate function 5698 ** implementation is never called and xFinal() is called exactly once. 5699 ** In those cases, sqlite3_aggregate_context() might be called for the 5700 ** first time from within xFinal().)^ 5701 ** 5702 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5703 ** when first called if N is less than or equal to zero or if a memory 5704 ** allocation error occurs. 5705 ** 5706 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5707 ** determined by the N parameter on first successful call. Changing the 5708 ** value of N in any subsequent call to sqlite3_aggregate_context() within 5709 ** the same aggregate function instance will not resize the memory 5710 ** allocation.)^ Within the xFinal callback, it is customary to set 5711 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5712 ** pointless memory allocations occur. 5713 ** 5714 ** ^SQLite automatically frees the memory allocated by 5715 ** sqlite3_aggregate_context() when the aggregate query concludes. 5716 ** 5717 ** The first parameter must be a copy of the 5718 ** [sqlite3_context | SQL function context] that is the first parameter 5719 ** to the xStep or xFinal callback routine that implements the aggregate 5720 ** function. 5721 ** 5722 ** This routine must be called from the same thread in which 5723 ** the aggregate SQL function is running. 5724 */ 5725 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5726 5727 /* 5728 ** CAPI3REF: User Data For Functions 5729 ** METHOD: sqlite3_context 5730 ** 5731 ** ^The sqlite3_user_data() interface returns a copy of 5732 ** the pointer that was the pUserData parameter (the 5th parameter) 5733 ** of the [sqlite3_create_function()] 5734 ** and [sqlite3_create_function16()] routines that originally 5735 ** registered the application defined function. 5736 ** 5737 ** This routine must be called from the same thread in which 5738 ** the application-defined function is running. 5739 */ 5740 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5741 5742 /* 5743 ** CAPI3REF: Database Connection For Functions 5744 ** METHOD: sqlite3_context 5745 ** 5746 ** ^The sqlite3_context_db_handle() interface returns a copy of 5747 ** the pointer to the [database connection] (the 1st parameter) 5748 ** of the [sqlite3_create_function()] 5749 ** and [sqlite3_create_function16()] routines that originally 5750 ** registered the application defined function. 5751 */ 5752 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5753 5754 /* 5755 ** CAPI3REF: Function Auxiliary Data 5756 ** METHOD: sqlite3_context 5757 ** 5758 ** These functions may be used by (non-aggregate) SQL functions to 5759 ** associate metadata with argument values. If the same value is passed to 5760 ** multiple invocations of the same SQL function during query execution, under 5761 ** some circumstances the associated metadata may be preserved. An example 5762 ** of where this might be useful is in a regular-expression matching 5763 ** function. The compiled version of the regular expression can be stored as 5764 ** metadata associated with the pattern string. 5765 ** Then as long as the pattern string remains the same, 5766 ** the compiled regular expression can be reused on multiple 5767 ** invocations of the same function. 5768 ** 5769 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5770 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5771 ** value to the application-defined function. ^N is zero for the left-most 5772 ** function argument. ^If there is no metadata 5773 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5774 ** returns a NULL pointer. 5775 ** 5776 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5777 ** argument of the application-defined function. ^Subsequent 5778 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5779 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5780 ** NULL if the metadata has been discarded. 5781 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5782 ** SQLite will invoke the destructor function X with parameter P exactly 5783 ** once, when the metadata is discarded. 5784 ** SQLite is free to discard the metadata at any time, including: <ul> 5785 ** <li> ^(when the corresponding function parameter changes)^, or 5786 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5787 ** SQL statement)^, or 5788 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5789 ** parameter)^, or 5790 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5791 ** allocation error occurs.)^ </ul> 5792 ** 5793 ** Note the last bullet in particular. The destructor X in 5794 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5795 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5796 ** should be called near the end of the function implementation and the 5797 ** function implementation should not make any use of P after 5798 ** sqlite3_set_auxdata() has been called. 5799 ** 5800 ** ^(In practice, metadata is preserved between function calls for 5801 ** function parameters that are compile-time constants, including literal 5802 ** values and [parameters] and expressions composed from the same.)^ 5803 ** 5804 ** The value of the N parameter to these interfaces should be non-negative. 5805 ** Future enhancements may make use of negative N values to define new 5806 ** kinds of function caching behavior. 5807 ** 5808 ** These routines must be called from the same thread in which 5809 ** the SQL function is running. 5810 */ 5811 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5812 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5813 5814 5815 /* 5816 ** CAPI3REF: Constants Defining Special Destructor Behavior 5817 ** 5818 ** These are special values for the destructor that is passed in as the 5819 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5820 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5821 ** and will never change. It does not need to be destroyed. ^The 5822 ** SQLITE_TRANSIENT value means that the content will likely change in 5823 ** the near future and that SQLite should make its own private copy of 5824 ** the content before returning. 5825 ** 5826 ** The typedef is necessary to work around problems in certain 5827 ** C++ compilers. 5828 */ 5829 typedef void (*sqlite3_destructor_type)(void*); 5830 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5831 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5832 5833 /* 5834 ** CAPI3REF: Setting The Result Of An SQL Function 5835 ** METHOD: sqlite3_context 5836 ** 5837 ** These routines are used by the xFunc or xFinal callbacks that 5838 ** implement SQL functions and aggregates. See 5839 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5840 ** for additional information. 5841 ** 5842 ** These functions work very much like the [parameter binding] family of 5843 ** functions used to bind values to host parameters in prepared statements. 5844 ** Refer to the [SQL parameter] documentation for additional information. 5845 ** 5846 ** ^The sqlite3_result_blob() interface sets the result from 5847 ** an application-defined function to be the BLOB whose content is pointed 5848 ** to by the second parameter and which is N bytes long where N is the 5849 ** third parameter. 5850 ** 5851 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5852 ** interfaces set the result of the application-defined function to be 5853 ** a BLOB containing all zero bytes and N bytes in size. 5854 ** 5855 ** ^The sqlite3_result_double() interface sets the result from 5856 ** an application-defined function to be a floating point value specified 5857 ** by its 2nd argument. 5858 ** 5859 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5860 ** cause the implemented SQL function to throw an exception. 5861 ** ^SQLite uses the string pointed to by the 5862 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5863 ** as the text of an error message. ^SQLite interprets the error 5864 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5865 ** interprets the string from sqlite3_result_error16() as UTF-16 using 5866 ** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5867 ** ^If the third parameter to sqlite3_result_error() 5868 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5869 ** message all text up through the first zero character. 5870 ** ^If the third parameter to sqlite3_result_error() or 5871 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5872 ** bytes (not characters) from the 2nd parameter as the error message. 5873 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5874 ** routines make a private copy of the error message text before 5875 ** they return. Hence, the calling function can deallocate or 5876 ** modify the text after they return without harm. 5877 ** ^The sqlite3_result_error_code() function changes the error code 5878 ** returned by SQLite as a result of an error in a function. ^By default, 5879 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5880 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5881 ** 5882 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5883 ** error indicating that a string or BLOB is too long to represent. 5884 ** 5885 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5886 ** error indicating that a memory allocation failed. 5887 ** 5888 ** ^The sqlite3_result_int() interface sets the return value 5889 ** of the application-defined function to be the 32-bit signed integer 5890 ** value given in the 2nd argument. 5891 ** ^The sqlite3_result_int64() interface sets the return value 5892 ** of the application-defined function to be the 64-bit signed integer 5893 ** value given in the 2nd argument. 5894 ** 5895 ** ^The sqlite3_result_null() interface sets the return value 5896 ** of the application-defined function to be NULL. 5897 ** 5898 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5899 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5900 ** set the return value of the application-defined function to be 5901 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5902 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5903 ** ^The sqlite3_result_text64() interface sets the return value of an 5904 ** application-defined function to be a text string in an encoding 5905 ** specified by the fifth (and last) parameter, which must be one 5906 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5907 ** ^SQLite takes the text result from the application from 5908 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5909 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 5910 ** other than sqlite3_result_text64() is negative, then SQLite computes 5911 ** the string length itself by searching the 2nd parameter for the first 5912 ** zero character. 5913 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5914 ** is non-negative, then as many bytes (not characters) of the text 5915 ** pointed to by the 2nd parameter are taken as the application-defined 5916 ** function result. If the 3rd parameter is non-negative, then it 5917 ** must be the byte offset into the string where the NUL terminator would 5918 ** appear if the string where NUL terminated. If any NUL characters occur 5919 ** in the string at a byte offset that is less than the value of the 3rd 5920 ** parameter, then the resulting string will contain embedded NULs and the 5921 ** result of expressions operating on strings with embedded NULs is undefined. 5922 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5923 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5924 ** function as the destructor on the text or BLOB result when it has 5925 ** finished using that result. 5926 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5927 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5928 ** assumes that the text or BLOB result is in constant space and does not 5929 ** copy the content of the parameter nor call a destructor on the content 5930 ** when it has finished using that result. 5931 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5932 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5933 ** then SQLite makes a copy of the result into space obtained 5934 ** from [sqlite3_malloc()] before it returns. 5935 ** 5936 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5937 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5938 ** when the encoding is not UTF8, if the input UTF16 begins with a 5939 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5940 ** string and the rest of the string is interpreted according to the 5941 ** byte-order specified by the BOM. ^The byte-order specified by 5942 ** the BOM at the beginning of the text overrides the byte-order 5943 ** specified by the interface procedure. ^So, for example, if 5944 ** sqlite3_result_text16le() is invoked with text that begins 5945 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5946 ** first two bytes of input are skipped and the remaining input 5947 ** is interpreted as UTF16BE text. 5948 ** 5949 ** ^For UTF16 input text to the sqlite3_result_text16(), 5950 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5951 ** sqlite3_result_text64() routines, if the text contains invalid 5952 ** UTF16 characters, the invalid characters might be converted 5953 ** into the unicode replacement character, U+FFFD. 5954 ** 5955 ** ^The sqlite3_result_value() interface sets the result of 5956 ** the application-defined function to be a copy of the 5957 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5958 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5959 ** so that the [sqlite3_value] specified in the parameter may change or 5960 ** be deallocated after sqlite3_result_value() returns without harm. 5961 ** ^A [protected sqlite3_value] object may always be used where an 5962 ** [unprotected sqlite3_value] object is required, so either 5963 ** kind of [sqlite3_value] object can be used with this interface. 5964 ** 5965 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5966 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5967 ** also associates the host-language pointer P or type T with that 5968 ** NULL value such that the pointer can be retrieved within an 5969 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5970 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5971 ** for the P parameter. ^SQLite invokes D with P as its only argument 5972 ** when SQLite is finished with P. The T parameter should be a static 5973 ** string and preferably a string literal. The sqlite3_result_pointer() 5974 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5975 ** 5976 ** If these routines are called from within the different thread 5977 ** than the one containing the application-defined function that received 5978 ** the [sqlite3_context] pointer, the results are undefined. 5979 */ 5980 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5981 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5982 sqlite3_uint64,void(*)(void*)); 5983 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5984 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5985 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5986 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5987 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5988 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5989 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5990 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5991 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5992 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5993 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5994 void(*)(void*), unsigned char encoding); 5995 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5996 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5997 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5998 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5999 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 6000 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 6001 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 6002 6003 6004 /* 6005 ** CAPI3REF: Setting The Subtype Of An SQL Function 6006 ** METHOD: sqlite3_context 6007 ** 6008 ** The sqlite3_result_subtype(C,T) function causes the subtype of 6009 ** the result from the [application-defined SQL function] with 6010 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 6011 ** of the subtype T are preserved in current versions of SQLite; 6012 ** higher order bits are discarded. 6013 ** The number of subtype bytes preserved by SQLite might increase 6014 ** in future releases of SQLite. 6015 */ 6016 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6017 6018 /* 6019 ** CAPI3REF: Define New Collating Sequences 6020 ** METHOD: sqlite3 6021 ** 6022 ** ^These functions add, remove, or modify a [collation] associated 6023 ** with the [database connection] specified as the first argument. 6024 ** 6025 ** ^The name of the collation is a UTF-8 string 6026 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6027 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6028 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6029 ** considered to be the same name. 6030 ** 6031 ** ^(The third argument (eTextRep) must be one of the constants: 6032 ** <ul> 6033 ** <li> [SQLITE_UTF8], 6034 ** <li> [SQLITE_UTF16LE], 6035 ** <li> [SQLITE_UTF16BE], 6036 ** <li> [SQLITE_UTF16], or 6037 ** <li> [SQLITE_UTF16_ALIGNED]. 6038 ** </ul>)^ 6039 ** ^The eTextRep argument determines the encoding of strings passed 6040 ** to the collating function callback, xCompare. 6041 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6042 ** force strings to be UTF16 with native byte order. 6043 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6044 ** on an even byte address. 6045 ** 6046 ** ^The fourth argument, pArg, is an application data pointer that is passed 6047 ** through as the first argument to the collating function callback. 6048 ** 6049 ** ^The fifth argument, xCompare, is a pointer to the collating function. 6050 ** ^Multiple collating functions can be registered using the same name but 6051 ** with different eTextRep parameters and SQLite will use whichever 6052 ** function requires the least amount of data transformation. 6053 ** ^If the xCompare argument is NULL then the collating function is 6054 ** deleted. ^When all collating functions having the same name are deleted, 6055 ** that collation is no longer usable. 6056 ** 6057 ** ^The collating function callback is invoked with a copy of the pArg 6058 ** application data pointer and with two strings in the encoding specified 6059 ** by the eTextRep argument. The two integer parameters to the collating 6060 ** function callback are the length of the two strings, in bytes. The collating 6061 ** function must return an integer that is negative, zero, or positive 6062 ** if the first string is less than, equal to, or greater than the second, 6063 ** respectively. A collating function must always return the same answer 6064 ** given the same inputs. If two or more collating functions are registered 6065 ** to the same collation name (using different eTextRep values) then all 6066 ** must give an equivalent answer when invoked with equivalent strings. 6067 ** The collating function must obey the following properties for all 6068 ** strings A, B, and C: 6069 ** 6070 ** <ol> 6071 ** <li> If A==B then B==A. 6072 ** <li> If A==B and B==C then A==C. 6073 ** <li> If A<B THEN B>A. 6074 ** <li> If A<B and B<C then A<C. 6075 ** </ol> 6076 ** 6077 ** If a collating function fails any of the above constraints and that 6078 ** collating function is registered and used, then the behavior of SQLite 6079 ** is undefined. 6080 ** 6081 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6082 ** with the addition that the xDestroy callback is invoked on pArg when 6083 ** the collating function is deleted. 6084 ** ^Collating functions are deleted when they are overridden by later 6085 ** calls to the collation creation functions or when the 6086 ** [database connection] is closed using [sqlite3_close()]. 6087 ** 6088 ** ^The xDestroy callback is <u>not</u> called if the 6089 ** sqlite3_create_collation_v2() function fails. Applications that invoke 6090 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6091 ** check the return code and dispose of the application data pointer 6092 ** themselves rather than expecting SQLite to deal with it for them. 6093 ** This is different from every other SQLite interface. The inconsistency 6094 ** is unfortunate but cannot be changed without breaking backwards 6095 ** compatibility. 6096 ** 6097 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6098 */ 6099 SQLITE_API int sqlite3_create_collation( 6100 sqlite3*, 6101 const char *zName, 6102 int eTextRep, 6103 void *pArg, 6104 int(*xCompare)(void*,int,const void*,int,const void*) 6105 ); 6106 SQLITE_API int sqlite3_create_collation_v2( 6107 sqlite3*, 6108 const char *zName, 6109 int eTextRep, 6110 void *pArg, 6111 int(*xCompare)(void*,int,const void*,int,const void*), 6112 void(*xDestroy)(void*) 6113 ); 6114 SQLITE_API int sqlite3_create_collation16( 6115 sqlite3*, 6116 const void *zName, 6117 int eTextRep, 6118 void *pArg, 6119 int(*xCompare)(void*,int,const void*,int,const void*) 6120 ); 6121 6122 /* 6123 ** CAPI3REF: Collation Needed Callbacks 6124 ** METHOD: sqlite3 6125 ** 6126 ** ^To avoid having to register all collation sequences before a database 6127 ** can be used, a single callback function may be registered with the 6128 ** [database connection] to be invoked whenever an undefined collation 6129 ** sequence is required. 6130 ** 6131 ** ^If the function is registered using the sqlite3_collation_needed() API, 6132 ** then it is passed the names of undefined collation sequences as strings 6133 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6134 ** the names are passed as UTF-16 in machine native byte order. 6135 ** ^A call to either function replaces the existing collation-needed callback. 6136 ** 6137 ** ^(When the callback is invoked, the first argument passed is a copy 6138 ** of the second argument to sqlite3_collation_needed() or 6139 ** sqlite3_collation_needed16(). The second argument is the database 6140 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6141 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6142 ** sequence function required. The fourth parameter is the name of the 6143 ** required collation sequence.)^ 6144 ** 6145 ** The callback function should register the desired collation using 6146 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6147 ** [sqlite3_create_collation_v2()]. 6148 */ 6149 SQLITE_API int sqlite3_collation_needed( 6150 sqlite3*, 6151 void*, 6152 void(*)(void*,sqlite3*,int eTextRep,const char*) 6153 ); 6154 SQLITE_API int sqlite3_collation_needed16( 6155 sqlite3*, 6156 void*, 6157 void(*)(void*,sqlite3*,int eTextRep,const void*) 6158 ); 6159 6160 #ifdef SQLITE_HAS_CODEC 6161 /* 6162 ** Specify the key for an encrypted database. This routine should be 6163 ** called right after sqlite3_open(). 6164 ** 6165 ** The code to implement this API is not available in the public release 6166 ** of SQLite. 6167 */ 6168 SQLITE_API int sqlite3_key( 6169 sqlite3 *db, /* Database to be rekeyed */ 6170 const void *pKey, int nKey /* The key */ 6171 ); 6172 SQLITE_API int sqlite3_key_v2( 6173 sqlite3 *db, /* Database to be rekeyed */ 6174 const char *zDbName, /* Name of the database */ 6175 const void *pKey, int nKey /* The key */ 6176 ); 6177 6178 /* 6179 ** Change the key on an open database. If the current database is not 6180 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 6181 ** database is decrypted. 6182 ** 6183 ** The code to implement this API is not available in the public release 6184 ** of SQLite. 6185 */ 6186 SQLITE_API int sqlite3_rekey( 6187 sqlite3 *db, /* Database to be rekeyed */ 6188 const void *pKey, int nKey /* The new key */ 6189 ); 6190 SQLITE_API int sqlite3_rekey_v2( 6191 sqlite3 *db, /* Database to be rekeyed */ 6192 const char *zDbName, /* Name of the database */ 6193 const void *pKey, int nKey /* The new key */ 6194 ); 6195 6196 #endif 6197 6198 #ifdef SQLITE_ENABLE_CEROD 6199 /* 6200 ** Specify the activation key for a CEROD database. Unless 6201 ** activated, none of the CEROD routines will work. 6202 */ 6203 SQLITE_API void sqlite3_activate_cerod( 6204 const char *zPassPhrase /* Activation phrase */ 6205 ); 6206 #endif 6207 6208 /* 6209 ** CAPI3REF: Suspend Execution For A Short Time 6210 ** 6211 ** The sqlite3_sleep() function causes the current thread to suspend execution 6212 ** for at least a number of milliseconds specified in its parameter. 6213 ** 6214 ** If the operating system does not support sleep requests with 6215 ** millisecond time resolution, then the time will be rounded up to 6216 ** the nearest second. The number of milliseconds of sleep actually 6217 ** requested from the operating system is returned. 6218 ** 6219 ** ^SQLite implements this interface by calling the xSleep() 6220 ** method of the default [sqlite3_vfs] object. If the xSleep() method 6221 ** of the default VFS is not implemented correctly, or not implemented at 6222 ** all, then the behavior of sqlite3_sleep() may deviate from the description 6223 ** in the previous paragraphs. 6224 */ 6225 SQLITE_API int sqlite3_sleep(int); 6226 6227 /* 6228 ** CAPI3REF: Name Of The Folder Holding Temporary Files 6229 ** 6230 ** ^(If this global variable is made to point to a string which is 6231 ** the name of a folder (a.k.a. directory), then all temporary files 6232 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6233 ** will be placed in that directory.)^ ^If this variable 6234 ** is a NULL pointer, then SQLite performs a search for an appropriate 6235 ** temporary file directory. 6236 ** 6237 ** Applications are strongly discouraged from using this global variable. 6238 ** It is required to set a temporary folder on Windows Runtime (WinRT). 6239 ** But for all other platforms, it is highly recommended that applications 6240 ** neither read nor write this variable. This global variable is a relic 6241 ** that exists for backwards compatibility of legacy applications and should 6242 ** be avoided in new projects. 6243 ** 6244 ** It is not safe to read or modify this variable in more than one 6245 ** thread at a time. It is not safe to read or modify this variable 6246 ** if a [database connection] is being used at the same time in a separate 6247 ** thread. 6248 ** It is intended that this variable be set once 6249 ** as part of process initialization and before any SQLite interface 6250 ** routines have been called and that this variable remain unchanged 6251 ** thereafter. 6252 ** 6253 ** ^The [temp_store_directory pragma] may modify this variable and cause 6254 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6255 ** the [temp_store_directory pragma] always assumes that any string 6256 ** that this variable points to is held in memory obtained from 6257 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6258 ** using [sqlite3_free]. 6259 ** Hence, if this variable is modified directly, either it should be 6260 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6261 ** or else the use of the [temp_store_directory pragma] should be avoided. 6262 ** Except when requested by the [temp_store_directory pragma], SQLite 6263 ** does not free the memory that sqlite3_temp_directory points to. If 6264 ** the application wants that memory to be freed, it must do 6265 ** so itself, taking care to only do so after all [database connection] 6266 ** objects have been destroyed. 6267 ** 6268 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6269 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6270 ** features that require the use of temporary files may fail. Here is an 6271 ** example of how to do this using C++ with the Windows Runtime: 6272 ** 6273 ** <blockquote><pre> 6274 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6275 ** TemporaryFolder->Path->Data(); 6276 ** char zPathBuf[MAX_PATH + 1]; 6277 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 6278 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6279 ** NULL, NULL); 6280 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6281 ** </pre></blockquote> 6282 */ 6283 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6284 6285 /* 6286 ** CAPI3REF: Name Of The Folder Holding Database Files 6287 ** 6288 ** ^(If this global variable is made to point to a string which is 6289 ** the name of a folder (a.k.a. directory), then all database files 6290 ** specified with a relative pathname and created or accessed by 6291 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6292 ** to be relative to that directory.)^ ^If this variable is a NULL 6293 ** pointer, then SQLite assumes that all database files specified 6294 ** with a relative pathname are relative to the current directory 6295 ** for the process. Only the windows VFS makes use of this global 6296 ** variable; it is ignored by the unix VFS. 6297 ** 6298 ** Changing the value of this variable while a database connection is 6299 ** open can result in a corrupt database. 6300 ** 6301 ** It is not safe to read or modify this variable in more than one 6302 ** thread at a time. It is not safe to read or modify this variable 6303 ** if a [database connection] is being used at the same time in a separate 6304 ** thread. 6305 ** It is intended that this variable be set once 6306 ** as part of process initialization and before any SQLite interface 6307 ** routines have been called and that this variable remain unchanged 6308 ** thereafter. 6309 ** 6310 ** ^The [data_store_directory pragma] may modify this variable and cause 6311 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6312 ** the [data_store_directory pragma] always assumes that any string 6313 ** that this variable points to is held in memory obtained from 6314 ** [sqlite3_malloc] and the pragma may attempt to free that memory 6315 ** using [sqlite3_free]. 6316 ** Hence, if this variable is modified directly, either it should be 6317 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 6318 ** or else the use of the [data_store_directory pragma] should be avoided. 6319 */ 6320 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6321 6322 /* 6323 ** CAPI3REF: Win32 Specific Interface 6324 ** 6325 ** These interfaces are available only on Windows. The 6326 ** [sqlite3_win32_set_directory] interface is used to set the value associated 6327 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6328 ** zValue, depending on the value of the type parameter. The zValue parameter 6329 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6330 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6331 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 6332 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6333 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6334 ** [sqlite3_data_directory] variable is intended to act as a replacement for 6335 ** the current directory on the sub-platforms of Win32 where that concept is 6336 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6337 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6338 ** sqlite3_win32_set_directory interface except the string parameter must be 6339 ** UTF-8 or UTF-16, respectively. 6340 */ 6341 SQLITE_API int sqlite3_win32_set_directory( 6342 unsigned long type, /* Identifier for directory being set or reset */ 6343 void *zValue /* New value for directory being set or reset */ 6344 ); 6345 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6346 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6347 6348 /* 6349 ** CAPI3REF: Win32 Directory Types 6350 ** 6351 ** These macros are only available on Windows. They define the allowed values 6352 ** for the type argument to the [sqlite3_win32_set_directory] interface. 6353 */ 6354 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6355 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6356 6357 /* 6358 ** CAPI3REF: Test For Auto-Commit Mode 6359 ** KEYWORDS: {autocommit mode} 6360 ** METHOD: sqlite3 6361 ** 6362 ** ^The sqlite3_get_autocommit() interface returns non-zero or 6363 ** zero if the given database connection is or is not in autocommit mode, 6364 ** respectively. ^Autocommit mode is on by default. 6365 ** ^Autocommit mode is disabled by a [BEGIN] statement. 6366 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6367 ** 6368 ** If certain kinds of errors occur on a statement within a multi-statement 6369 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6370 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6371 ** transaction might be rolled back automatically. The only way to 6372 ** find out whether SQLite automatically rolled back the transaction after 6373 ** an error is to use this function. 6374 ** 6375 ** If another thread changes the autocommit status of the database 6376 ** connection while this routine is running, then the return value 6377 ** is undefined. 6378 */ 6379 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6380 6381 /* 6382 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 6383 ** METHOD: sqlite3_stmt 6384 ** 6385 ** ^The sqlite3_db_handle interface returns the [database connection] handle 6386 ** to which a [prepared statement] belongs. ^The [database connection] 6387 ** returned by sqlite3_db_handle is the same [database connection] 6388 ** that was the first argument 6389 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6390 ** create the statement in the first place. 6391 */ 6392 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6393 6394 /* 6395 ** CAPI3REF: Return The Schema Name For A Database Connection 6396 ** METHOD: sqlite3 6397 ** 6398 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6399 ** for the N-th database on database connection D, or a NULL pointer of N is 6400 ** out of range. An N value of 0 means the main database file. An N of 1 is 6401 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6402 ** databases. 6403 ** 6404 ** Space to hold the string that is returned by sqlite3_db_name() is managed 6405 ** by SQLite itself. The string might be deallocated by any operation that 6406 ** changes the schema, including [ATTACH] or [DETACH] or calls to 6407 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6408 ** occur on a different thread. Applications that need to 6409 ** remember the string long-term should make their own copy. Applications that 6410 ** are accessing the same database connection simultaneously on multiple 6411 ** threads should mutex-protect calls to this API and should make their own 6412 ** private copy of the result prior to releasing the mutex. 6413 */ 6414 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6415 6416 /* 6417 ** CAPI3REF: Return The Filename For A Database Connection 6418 ** METHOD: sqlite3 6419 ** 6420 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6421 ** associated with database N of connection D. 6422 ** ^If there is no attached database N on the database 6423 ** connection D, or if database N is a temporary or in-memory database, then 6424 ** this function will return either a NULL pointer or an empty string. 6425 ** 6426 ** ^The string value returned by this routine is owned and managed by 6427 ** the database connection. ^The value will be valid until the database N 6428 ** is [DETACH]-ed or until the database connection closes. 6429 ** 6430 ** ^The filename returned by this function is the output of the 6431 ** xFullPathname method of the [VFS]. ^In other words, the filename 6432 ** will be an absolute pathname, even if the filename used 6433 ** to open the database originally was a URI or relative pathname. 6434 ** 6435 ** If the filename pointer returned by this routine is not NULL, then it 6436 ** can be used as the filename input parameter to these routines: 6437 ** <ul> 6438 ** <li> [sqlite3_uri_parameter()] 6439 ** <li> [sqlite3_uri_boolean()] 6440 ** <li> [sqlite3_uri_int64()] 6441 ** <li> [sqlite3_filename_database()] 6442 ** <li> [sqlite3_filename_journal()] 6443 ** <li> [sqlite3_filename_wal()] 6444 ** </ul> 6445 */ 6446 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6447 6448 /* 6449 ** CAPI3REF: Determine if a database is read-only 6450 ** METHOD: sqlite3 6451 ** 6452 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6453 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6454 ** the name of a database on connection D. 6455 */ 6456 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6457 6458 /* 6459 ** CAPI3REF: Determine the transaction state of a database 6460 ** METHOD: sqlite3 6461 ** 6462 ** ^The sqlite3_txn_state(D,S) interface returns the current 6463 ** [transaction state] of schema S in database connection D. ^If S is NULL, 6464 ** then the highest transaction state of any schema on database connection D 6465 ** is returned. Transaction states are (in order of lowest to highest): 6466 ** <ol> 6467 ** <li value="0"> SQLITE_TXN_NONE 6468 ** <li value="1"> SQLITE_TXN_READ 6469 ** <li value="2"> SQLITE_TXN_WRITE 6470 ** </ol> 6471 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6472 ** a valid schema, then -1 is returned. 6473 */ 6474 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6475 6476 /* 6477 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6478 ** KEYWORDS: {transaction state} 6479 ** 6480 ** These constants define the current transaction state of a database file. 6481 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6482 ** constants in order to describe the transaction state of schema S 6483 ** in [database connection] D. 6484 ** 6485 ** <dl> 6486 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6487 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6488 ** pending.</dd> 6489 ** 6490 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6491 ** <dd>The SQLITE_TXN_READ state means that the database is currently 6492 ** in a read transaction. Content has been read from the database file 6493 ** but nothing in the database file has changed. The transaction state 6494 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6495 ** no other conflicting concurrent write transactions. The transaction 6496 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6497 ** [COMMIT].</dd> 6498 ** 6499 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6500 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6501 ** in a write transaction. Content has been written to the database file 6502 ** but has not yet committed. The transaction state will change to 6503 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6504 */ 6505 #define SQLITE_TXN_NONE 0 6506 #define SQLITE_TXN_READ 1 6507 #define SQLITE_TXN_WRITE 2 6508 6509 /* 6510 ** CAPI3REF: Find the next prepared statement 6511 ** METHOD: sqlite3 6512 ** 6513 ** ^This interface returns a pointer to the next [prepared statement] after 6514 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6515 ** then this interface returns a pointer to the first prepared statement 6516 ** associated with the database connection pDb. ^If no prepared statement 6517 ** satisfies the conditions of this routine, it returns NULL. 6518 ** 6519 ** The [database connection] pointer D in a call to 6520 ** [sqlite3_next_stmt(D,S)] must refer to an open database 6521 ** connection and in particular must not be a NULL pointer. 6522 */ 6523 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6524 6525 /* 6526 ** CAPI3REF: Commit And Rollback Notification Callbacks 6527 ** METHOD: sqlite3 6528 ** 6529 ** ^The sqlite3_commit_hook() interface registers a callback 6530 ** function to be invoked whenever a transaction is [COMMIT | committed]. 6531 ** ^Any callback set by a previous call to sqlite3_commit_hook() 6532 ** for the same database connection is overridden. 6533 ** ^The sqlite3_rollback_hook() interface registers a callback 6534 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6535 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 6536 ** for the same database connection is overridden. 6537 ** ^The pArg argument is passed through to the callback. 6538 ** ^If the callback on a commit hook function returns non-zero, 6539 ** then the commit is converted into a rollback. 6540 ** 6541 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6542 ** return the P argument from the previous call of the same function 6543 ** on the same [database connection] D, or NULL for 6544 ** the first call for each function on D. 6545 ** 6546 ** The commit and rollback hook callbacks are not reentrant. 6547 ** The callback implementation must not do anything that will modify 6548 ** the database connection that invoked the callback. Any actions 6549 ** to modify the database connection must be deferred until after the 6550 ** completion of the [sqlite3_step()] call that triggered the commit 6551 ** or rollback hook in the first place. 6552 ** Note that running any other SQL statements, including SELECT statements, 6553 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6554 ** the database connections for the meaning of "modify" in this paragraph. 6555 ** 6556 ** ^Registering a NULL function disables the callback. 6557 ** 6558 ** ^When the commit hook callback routine returns zero, the [COMMIT] 6559 ** operation is allowed to continue normally. ^If the commit hook 6560 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6561 ** ^The rollback hook is invoked on a rollback that results from a commit 6562 ** hook returning non-zero, just as it would be with any other rollback. 6563 ** 6564 ** ^For the purposes of this API, a transaction is said to have been 6565 ** rolled back if an explicit "ROLLBACK" statement is executed, or 6566 ** an error or constraint causes an implicit rollback to occur. 6567 ** ^The rollback callback is not invoked if a transaction is 6568 ** automatically rolled back because the database connection is closed. 6569 ** 6570 ** See also the [sqlite3_update_hook()] interface. 6571 */ 6572 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6573 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6574 6575 /* 6576 ** CAPI3REF: Autovacuum Compaction Amount Callback 6577 ** METHOD: sqlite3 6578 ** 6579 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6580 ** function C that is invoked prior to each autovacuum of the database 6581 ** file. ^The callback is passed a copy of the generic data pointer (P), 6582 ** the schema-name of the attached database that is being autovacuumed, 6583 ** the size of the database file in pages, the number of free pages, 6584 ** and the number of bytes per page, respectively. The callback should 6585 ** return the number of free pages that should be removed by the 6586 ** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6587 ** ^If the value returned is greater than or equal to the number of 6588 ** free pages, then a complete autovacuum happens. 6589 ** 6590 ** <p>^If there are multiple ATTACH-ed database files that are being 6591 ** modified as part of a transaction commit, then the autovacuum pages 6592 ** callback is invoked separately for each file. 6593 ** 6594 ** <p><b>The callback is not reentrant.</b> The callback function should 6595 ** not attempt to invoke any other SQLite interface. If it does, bad 6596 ** things may happen, including segmentation faults and corrupt database 6597 ** files. The callback function should be a simple function that 6598 ** does some arithmetic on its input parameters and returns a result. 6599 ** 6600 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6601 ** destructor for the P parameter. ^If X is not NULL, then X(P) is 6602 ** invoked whenever the database connection closes or when the callback 6603 ** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6604 ** 6605 ** <p>^There is only one autovacuum pages callback per database connection. 6606 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6607 ** previous invocations for that database connection. ^If the callback 6608 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6609 ** then the autovacuum steps callback is cancelled. The return value 6610 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6611 ** be some other error code if something goes wrong. The current 6612 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6613 ** return codes might be added in future releases. 6614 ** 6615 ** <p>If no autovacuum pages callback is specified (the usual case) or 6616 ** a NULL pointer is provided for the callback, 6617 ** then the default behavior is to vacuum all free pages. So, in other 6618 ** words, the default behavior is the same as if the callback function 6619 ** were something like this: 6620 ** 6621 ** <blockquote><pre> 6622 ** unsigned int demonstration_autovac_pages_callback( 6623 ** void *pClientData, 6624 ** const char *zSchema, 6625 ** unsigned int nDbPage, 6626 ** unsigned int nFreePage, 6627 ** unsigned int nBytePerPage 6628 ** ){ 6629 ** return nFreePage; 6630 ** } 6631 ** </pre></blockquote> 6632 */ 6633 SQLITE_API int sqlite3_autovacuum_pages( 6634 sqlite3 *db, 6635 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6636 void*, 6637 void(*)(void*) 6638 ); 6639 6640 6641 /* 6642 ** CAPI3REF: Data Change Notification Callbacks 6643 ** METHOD: sqlite3 6644 ** 6645 ** ^The sqlite3_update_hook() interface registers a callback function 6646 ** with the [database connection] identified by the first argument 6647 ** to be invoked whenever a row is updated, inserted or deleted in 6648 ** a [rowid table]. 6649 ** ^Any callback set by a previous call to this function 6650 ** for the same database connection is overridden. 6651 ** 6652 ** ^The second argument is a pointer to the function to invoke when a 6653 ** row is updated, inserted or deleted in a rowid table. 6654 ** ^The first argument to the callback is a copy of the third argument 6655 ** to sqlite3_update_hook(). 6656 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6657 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 6658 ** to be invoked. 6659 ** ^The third and fourth arguments to the callback contain pointers to the 6660 ** database and table name containing the affected row. 6661 ** ^The final callback parameter is the [rowid] of the row. 6662 ** ^In the case of an update, this is the [rowid] after the update takes place. 6663 ** 6664 ** ^(The update hook is not invoked when internal system tables are 6665 ** modified (i.e. sqlite_sequence).)^ 6666 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6667 ** 6668 ** ^In the current implementation, the update hook 6669 ** is not invoked when conflicting rows are deleted because of an 6670 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6671 ** invoked when rows are deleted using the [truncate optimization]. 6672 ** The exceptions defined in this paragraph might change in a future 6673 ** release of SQLite. 6674 ** 6675 ** The update hook implementation must not do anything that will modify 6676 ** the database connection that invoked the update hook. Any actions 6677 ** to modify the database connection must be deferred until after the 6678 ** completion of the [sqlite3_step()] call that triggered the update hook. 6679 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6680 ** database connections for the meaning of "modify" in this paragraph. 6681 ** 6682 ** ^The sqlite3_update_hook(D,C,P) function 6683 ** returns the P argument from the previous call 6684 ** on the same [database connection] D, or NULL for 6685 ** the first call on D. 6686 ** 6687 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6688 ** and [sqlite3_preupdate_hook()] interfaces. 6689 */ 6690 SQLITE_API void *sqlite3_update_hook( 6691 sqlite3*, 6692 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6693 void* 6694 ); 6695 6696 /* 6697 ** CAPI3REF: Enable Or Disable Shared Pager Cache 6698 ** 6699 ** ^(This routine enables or disables the sharing of the database cache 6700 ** and schema data structures between [database connection | connections] 6701 ** to the same database. Sharing is enabled if the argument is true 6702 ** and disabled if the argument is false.)^ 6703 ** 6704 ** This interface is omitted if SQLite is compiled with 6705 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6706 ** compile-time option is recommended because the 6707 ** [use of shared cache mode is discouraged]. 6708 ** 6709 ** ^Cache sharing is enabled and disabled for an entire process. 6710 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6711 ** In prior versions of SQLite, 6712 ** sharing was enabled or disabled for each thread separately. 6713 ** 6714 ** ^(The cache sharing mode set by this interface effects all subsequent 6715 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6716 ** Existing database connections continue to use the sharing mode 6717 ** that was in effect at the time they were opened.)^ 6718 ** 6719 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6720 ** successfully. An [error code] is returned otherwise.)^ 6721 ** 6722 ** ^Shared cache is disabled by default. It is recommended that it stay 6723 ** that way. In other words, do not use this routine. This interface 6724 ** continues to be provided for historical compatibility, but its use is 6725 ** discouraged. Any use of shared cache is discouraged. If shared cache 6726 ** must be used, it is recommended that shared cache only be enabled for 6727 ** individual database connections using the [sqlite3_open_v2()] interface 6728 ** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6729 ** 6730 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6731 ** and will always return SQLITE_MISUSE. On those systems, 6732 ** shared cache mode should be enabled per-database connection via 6733 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6734 ** 6735 ** This interface is threadsafe on processors where writing a 6736 ** 32-bit integer is atomic. 6737 ** 6738 ** See Also: [SQLite Shared-Cache Mode] 6739 */ 6740 SQLITE_API int sqlite3_enable_shared_cache(int); 6741 6742 /* 6743 ** CAPI3REF: Attempt To Free Heap Memory 6744 ** 6745 ** ^The sqlite3_release_memory() interface attempts to free N bytes 6746 ** of heap memory by deallocating non-essential memory allocations 6747 ** held by the database library. Memory used to cache database 6748 ** pages to improve performance is an example of non-essential memory. 6749 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 6750 ** which might be more or less than the amount requested. 6751 ** ^The sqlite3_release_memory() routine is a no-op returning zero 6752 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6753 ** 6754 ** See also: [sqlite3_db_release_memory()] 6755 */ 6756 SQLITE_API int sqlite3_release_memory(int); 6757 6758 /* 6759 ** CAPI3REF: Free Memory Used By A Database Connection 6760 ** METHOD: sqlite3 6761 ** 6762 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6763 ** memory as possible from database connection D. Unlike the 6764 ** [sqlite3_release_memory()] interface, this interface is in effect even 6765 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6766 ** omitted. 6767 ** 6768 ** See also: [sqlite3_release_memory()] 6769 */ 6770 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6771 6772 /* 6773 ** CAPI3REF: Impose A Limit On Heap Size 6774 ** 6775 ** These interfaces impose limits on the amount of heap memory that will be 6776 ** by all database connections within a single process. 6777 ** 6778 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6779 ** soft limit on the amount of heap memory that may be allocated by SQLite. 6780 ** ^SQLite strives to keep heap memory utilization below the soft heap 6781 ** limit by reducing the number of pages held in the page cache 6782 ** as heap memory usages approaches the limit. 6783 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 6784 ** below the limit, it will exceed the limit rather than generate 6785 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6786 ** is advisory only. 6787 ** 6788 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6789 ** N bytes on the amount of memory that will be allocated. ^The 6790 ** sqlite3_hard_heap_limit64(N) interface is similar to 6791 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6792 ** when the hard heap limit is reached. 6793 ** 6794 ** ^The return value from both sqlite3_soft_heap_limit64() and 6795 ** sqlite3_hard_heap_limit64() is the size of 6796 ** the heap limit prior to the call, or negative in the case of an 6797 ** error. ^If the argument N is negative 6798 ** then no change is made to the heap limit. Hence, the current 6799 ** size of heap limits can be determined by invoking 6800 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6801 ** 6802 ** ^Setting the heap limits to zero disables the heap limiter mechanism. 6803 ** 6804 ** ^The soft heap limit may not be greater than the hard heap limit. 6805 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6806 ** is invoked with a value of N that is greater than the hard heap limit, 6807 ** the soft heap limit is set to the value of the hard heap limit. 6808 ** ^The soft heap limit is automatically enabled whenever the hard heap 6809 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6810 ** the soft heap limit is outside the range of 1..N, then the soft heap 6811 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6812 ** hard heap limit is enabled makes the soft heap limit equal to the 6813 ** hard heap limit. 6814 ** 6815 ** The memory allocation limits can also be adjusted using 6816 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6817 ** 6818 ** ^(The heap limits are not enforced in the current implementation 6819 ** if one or more of following conditions are true: 6820 ** 6821 ** <ul> 6822 ** <li> The limit value is set to zero. 6823 ** <li> Memory accounting is disabled using a combination of the 6824 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6825 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6826 ** <li> An alternative page cache implementation is specified using 6827 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6828 ** <li> The page cache allocates from its own memory pool supplied 6829 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6830 ** from the heap. 6831 ** </ul>)^ 6832 ** 6833 ** The circumstances under which SQLite will enforce the heap limits may 6834 ** changes in future releases of SQLite. 6835 */ 6836 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6837 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6838 6839 /* 6840 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6841 ** DEPRECATED 6842 ** 6843 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6844 ** interface. This routine is provided for historical compatibility 6845 ** only. All new applications should use the 6846 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6847 */ 6848 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6849 6850 6851 /* 6852 ** CAPI3REF: Extract Metadata About A Column Of A Table 6853 ** METHOD: sqlite3 6854 ** 6855 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6856 ** information about column C of table T in database D 6857 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6858 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6859 ** the final five arguments with appropriate values if the specified 6860 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6861 ** SQLITE_ERROR if the specified column does not exist. 6862 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6863 ** NULL pointer, then this routine simply checks for the existence of the 6864 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6865 ** does not. If the table name parameter T in a call to 6866 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6867 ** undefined behavior. 6868 ** 6869 ** ^The column is identified by the second, third and fourth parameters to 6870 ** this function. ^(The second parameter is either the name of the database 6871 ** (i.e. "main", "temp", or an attached database) containing the specified 6872 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6873 ** for the table using the same algorithm used by the database engine to 6874 ** resolve unqualified table references. 6875 ** 6876 ** ^The third and fourth parameters to this function are the table and column 6877 ** name of the desired column, respectively. 6878 ** 6879 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6880 ** and subsequent parameters to this function. ^Any of these arguments may be 6881 ** NULL, in which case the corresponding element of metadata is omitted. 6882 ** 6883 ** ^(<blockquote> 6884 ** <table border="1"> 6885 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6886 ** 6887 ** <tr><td> 5th <td> const char* <td> Data type 6888 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6889 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6890 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6891 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6892 ** </table> 6893 ** </blockquote>)^ 6894 ** 6895 ** ^The memory pointed to by the character pointers returned for the 6896 ** declaration type and collation sequence is valid until the next 6897 ** call to any SQLite API function. 6898 ** 6899 ** ^If the specified table is actually a view, an [error code] is returned. 6900 ** 6901 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6902 ** is not a [WITHOUT ROWID] table and an 6903 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6904 ** parameters are set for the explicitly declared column. ^(If there is no 6905 ** [INTEGER PRIMARY KEY] column, then the outputs 6906 ** for the [rowid] are set as follows: 6907 ** 6908 ** <pre> 6909 ** data type: "INTEGER" 6910 ** collation sequence: "BINARY" 6911 ** not null: 0 6912 ** primary key: 1 6913 ** auto increment: 0 6914 ** </pre>)^ 6915 ** 6916 ** ^This function causes all database schemas to be read from disk and 6917 ** parsed, if that has not already been done, and returns an error if 6918 ** any errors are encountered while loading the schema. 6919 */ 6920 SQLITE_API int sqlite3_table_column_metadata( 6921 sqlite3 *db, /* Connection handle */ 6922 const char *zDbName, /* Database name or NULL */ 6923 const char *zTableName, /* Table name */ 6924 const char *zColumnName, /* Column name */ 6925 char const **pzDataType, /* OUTPUT: Declared data type */ 6926 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6927 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6928 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6929 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6930 ); 6931 6932 /* 6933 ** CAPI3REF: Load An Extension 6934 ** METHOD: sqlite3 6935 ** 6936 ** ^This interface loads an SQLite extension library from the named file. 6937 ** 6938 ** ^The sqlite3_load_extension() interface attempts to load an 6939 ** [SQLite extension] library contained in the file zFile. If 6940 ** the file cannot be loaded directly, attempts are made to load 6941 ** with various operating-system specific extensions added. 6942 ** So for example, if "samplelib" cannot be loaded, then names like 6943 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6944 ** be tried also. 6945 ** 6946 ** ^The entry point is zProc. 6947 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6948 ** entry point name on its own. It first tries "sqlite3_extension_init". 6949 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6950 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6951 ** characters in the filename from the last "/" to the first following 6952 ** "." and omitting any initial "lib".)^ 6953 ** ^The sqlite3_load_extension() interface returns 6954 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6955 ** ^If an error occurs and pzErrMsg is not 0, then the 6956 ** [sqlite3_load_extension()] interface shall attempt to 6957 ** fill *pzErrMsg with error message text stored in memory 6958 ** obtained from [sqlite3_malloc()]. The calling function 6959 ** should free this memory by calling [sqlite3_free()]. 6960 ** 6961 ** ^Extension loading must be enabled using 6962 ** [sqlite3_enable_load_extension()] or 6963 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6964 ** prior to calling this API, 6965 ** otherwise an error will be returned. 6966 ** 6967 ** <b>Security warning:</b> It is recommended that the 6968 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6969 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6970 ** should be avoided. This will keep the SQL function [load_extension()] 6971 ** disabled and prevent SQL injections from giving attackers 6972 ** access to extension loading capabilities. 6973 ** 6974 ** See also the [load_extension() SQL function]. 6975 */ 6976 SQLITE_API int sqlite3_load_extension( 6977 sqlite3 *db, /* Load the extension into this database connection */ 6978 const char *zFile, /* Name of the shared library containing extension */ 6979 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6980 char **pzErrMsg /* Put error message here if not 0 */ 6981 ); 6982 6983 /* 6984 ** CAPI3REF: Enable Or Disable Extension Loading 6985 ** METHOD: sqlite3 6986 ** 6987 ** ^So as not to open security holes in older applications that are 6988 ** unprepared to deal with [extension loading], and as a means of disabling 6989 ** [extension loading] while evaluating user-entered SQL, the following API 6990 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6991 ** 6992 ** ^Extension loading is off by default. 6993 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6994 ** to turn extension loading on and call it with onoff==0 to turn 6995 ** it back off again. 6996 ** 6997 ** ^This interface enables or disables both the C-API 6998 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6999 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 7000 ** to enable or disable only the C-API.)^ 7001 ** 7002 ** <b>Security warning:</b> It is recommended that extension loading 7003 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 7004 ** rather than this interface, so the [load_extension()] SQL function 7005 ** remains disabled. This will prevent SQL injections from giving attackers 7006 ** access to extension loading capabilities. 7007 */ 7008 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 7009 7010 /* 7011 ** CAPI3REF: Automatically Load Statically Linked Extensions 7012 ** 7013 ** ^This interface causes the xEntryPoint() function to be invoked for 7014 ** each new [database connection] that is created. The idea here is that 7015 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 7016 ** that is to be automatically loaded into all new database connections. 7017 ** 7018 ** ^(Even though the function prototype shows that xEntryPoint() takes 7019 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 7020 ** arguments and expects an integer result as if the signature of the 7021 ** entry point where as follows: 7022 ** 7023 ** <blockquote><pre> 7024 ** int xEntryPoint( 7025 ** sqlite3 *db, 7026 ** const char **pzErrMsg, 7027 ** const struct sqlite3_api_routines *pThunk 7028 ** ); 7029 ** </pre></blockquote>)^ 7030 ** 7031 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7032 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7033 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7034 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7035 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7036 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7037 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7038 ** 7039 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7040 ** on the list of automatic extensions is a harmless no-op. ^No entry point 7041 ** will be called more than once for each database connection that is opened. 7042 ** 7043 ** See also: [sqlite3_reset_auto_extension()] 7044 ** and [sqlite3_cancel_auto_extension()] 7045 */ 7046 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7047 7048 /* 7049 ** CAPI3REF: Cancel Automatic Extension Loading 7050 ** 7051 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7052 ** initialization routine X that was registered using a prior call to 7053 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7054 ** routine returns 1 if initialization routine X was successfully 7055 ** unregistered and it returns 0 if X was not on the list of initialization 7056 ** routines. 7057 */ 7058 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7059 7060 /* 7061 ** CAPI3REF: Reset Automatic Extension Loading 7062 ** 7063 ** ^This interface disables all automatic extensions previously 7064 ** registered using [sqlite3_auto_extension()]. 7065 */ 7066 SQLITE_API void sqlite3_reset_auto_extension(void); 7067 7068 /* 7069 ** The interface to the virtual-table mechanism is currently considered 7070 ** to be experimental. The interface might change in incompatible ways. 7071 ** If this is a problem for you, do not use the interface at this time. 7072 ** 7073 ** When the virtual-table mechanism stabilizes, we will declare the 7074 ** interface fixed, support it indefinitely, and remove this comment. 7075 */ 7076 7077 /* 7078 ** Structures used by the virtual table interface 7079 */ 7080 typedef struct sqlite3_vtab sqlite3_vtab; 7081 typedef struct sqlite3_index_info sqlite3_index_info; 7082 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7083 typedef struct sqlite3_module sqlite3_module; 7084 7085 /* 7086 ** CAPI3REF: Virtual Table Object 7087 ** KEYWORDS: sqlite3_module {virtual table module} 7088 ** 7089 ** This structure, sometimes called a "virtual table module", 7090 ** defines the implementation of a [virtual table]. 7091 ** This structure consists mostly of methods for the module. 7092 ** 7093 ** ^A virtual table module is created by filling in a persistent 7094 ** instance of this structure and passing a pointer to that instance 7095 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7096 ** ^The registration remains valid until it is replaced by a different 7097 ** module or until the [database connection] closes. The content 7098 ** of this structure must not change while it is registered with 7099 ** any database connection. 7100 */ 7101 struct sqlite3_module { 7102 int iVersion; 7103 int (*xCreate)(sqlite3*, void *pAux, 7104 int argc, const char *const*argv, 7105 sqlite3_vtab **ppVTab, char**); 7106 int (*xConnect)(sqlite3*, void *pAux, 7107 int argc, const char *const*argv, 7108 sqlite3_vtab **ppVTab, char**); 7109 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7110 int (*xDisconnect)(sqlite3_vtab *pVTab); 7111 int (*xDestroy)(sqlite3_vtab *pVTab); 7112 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7113 int (*xClose)(sqlite3_vtab_cursor*); 7114 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7115 int argc, sqlite3_value **argv); 7116 int (*xNext)(sqlite3_vtab_cursor*); 7117 int (*xEof)(sqlite3_vtab_cursor*); 7118 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7119 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7120 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7121 int (*xBegin)(sqlite3_vtab *pVTab); 7122 int (*xSync)(sqlite3_vtab *pVTab); 7123 int (*xCommit)(sqlite3_vtab *pVTab); 7124 int (*xRollback)(sqlite3_vtab *pVTab); 7125 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7126 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7127 void **ppArg); 7128 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7129 /* The methods above are in version 1 of the sqlite_module object. Those 7130 ** below are for version 2 and greater. */ 7131 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7132 int (*xRelease)(sqlite3_vtab *pVTab, int); 7133 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7134 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7135 ** Those below are for version 3 and greater. */ 7136 int (*xShadowName)(const char*); 7137 }; 7138 7139 /* 7140 ** CAPI3REF: Virtual Table Indexing Information 7141 ** KEYWORDS: sqlite3_index_info 7142 ** 7143 ** The sqlite3_index_info structure and its substructures is used as part 7144 ** of the [virtual table] interface to 7145 ** pass information into and receive the reply from the [xBestIndex] 7146 ** method of a [virtual table module]. The fields under **Inputs** are the 7147 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 7148 ** results into the **Outputs** fields. 7149 ** 7150 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 7151 ** 7152 ** <blockquote>column OP expr</blockquote> 7153 ** 7154 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7155 ** stored in aConstraint[].op using one of the 7156 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7157 ** ^(The index of the column is stored in 7158 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7159 ** expr on the right-hand side can be evaluated (and thus the constraint 7160 ** is usable) and false if it cannot.)^ 7161 ** 7162 ** ^The optimizer automatically inverts terms of the form "expr OP column" 7163 ** and makes other simplifications to the WHERE clause in an attempt to 7164 ** get as many WHERE clause terms into the form shown above as possible. 7165 ** ^The aConstraint[] array only reports WHERE clause terms that are 7166 ** relevant to the particular virtual table being queried. 7167 ** 7168 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7169 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 7170 ** 7171 ** The colUsed field indicates which columns of the virtual table may be 7172 ** required by the current scan. Virtual table columns are numbered from 7173 ** zero in the order in which they appear within the CREATE TABLE statement 7174 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7175 ** the corresponding bit is set within the colUsed mask if the column may be 7176 ** required by SQLite. If the table has at least 64 columns and any column 7177 ** to the right of the first 63 is required, then bit 63 of colUsed is also 7178 ** set. In other words, column iCol may be required if the expression 7179 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7180 ** non-zero. 7181 ** 7182 ** The [xBestIndex] method must fill aConstraintUsage[] with information 7183 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 7184 ** the right-hand side of the corresponding aConstraint[] is evaluated 7185 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7186 ** is true, then the constraint is assumed to be fully handled by the 7187 ** virtual table and might not be checked again by the byte code.)^ ^(The 7188 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7189 ** is left in its default setting of false, the constraint will always be 7190 ** checked separately in byte code. If the omit flag is change to true, then 7191 ** the constraint may or may not be checked in byte code. In other words, 7192 ** when the omit flag is true there is no guarantee that the constraint will 7193 ** not be checked again using byte code.)^ 7194 ** 7195 ** ^The idxNum and idxPtr values are recorded and passed into the 7196 ** [xFilter] method. 7197 ** ^[sqlite3_free()] is used to free idxPtr if and only if 7198 ** needToFreeIdxPtr is true. 7199 ** 7200 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7201 ** the correct order to satisfy the ORDER BY clause so that no separate 7202 ** sorting step is required. 7203 ** 7204 ** ^The estimatedCost value is an estimate of the cost of a particular 7205 ** strategy. A cost of N indicates that the cost of the strategy is similar 7206 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 7207 ** indicates that the expense of the operation is similar to that of a 7208 ** binary search on a unique indexed field of an SQLite table with N rows. 7209 ** 7210 ** ^The estimatedRows value is an estimate of the number of rows that 7211 ** will be returned by the strategy. 7212 ** 7213 ** The xBestIndex method may optionally populate the idxFlags field with a 7214 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7215 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7216 ** assumes that the strategy may visit at most one row. 7217 ** 7218 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7219 ** SQLite also assumes that if a call to the xUpdate() method is made as 7220 ** part of the same statement to delete or update a virtual table row and the 7221 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7222 ** any database changes. In other words, if the xUpdate() returns 7223 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7224 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7225 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7226 ** the xUpdate method are automatically rolled back by SQLite. 7227 ** 7228 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7229 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7230 ** If a virtual table extension is 7231 ** used with an SQLite version earlier than 3.8.2, the results of attempting 7232 ** to read or write the estimatedRows field are undefined (but are likely 7233 ** to include crashing the application). The estimatedRows field should 7234 ** therefore only be used if [sqlite3_libversion_number()] returns a 7235 ** value greater than or equal to 3008002. Similarly, the idxFlags field 7236 ** was added for [version 3.9.0] ([dateof:3.9.0]). 7237 ** It may therefore only be used if 7238 ** sqlite3_libversion_number() returns a value greater than or equal to 7239 ** 3009000. 7240 */ 7241 struct sqlite3_index_info { 7242 /* Inputs */ 7243 int nConstraint; /* Number of entries in aConstraint */ 7244 struct sqlite3_index_constraint { 7245 int iColumn; /* Column constrained. -1 for ROWID */ 7246 unsigned char op; /* Constraint operator */ 7247 unsigned char usable; /* True if this constraint is usable */ 7248 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7249 } *aConstraint; /* Table of WHERE clause constraints */ 7250 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7251 struct sqlite3_index_orderby { 7252 int iColumn; /* Column number */ 7253 unsigned char desc; /* True for DESC. False for ASC. */ 7254 } *aOrderBy; /* The ORDER BY clause */ 7255 /* Outputs */ 7256 struct sqlite3_index_constraint_usage { 7257 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7258 unsigned char omit; /* Do not code a test for this constraint */ 7259 } *aConstraintUsage; 7260 int idxNum; /* Number used to identify the index */ 7261 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7262 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7263 int orderByConsumed; /* True if output is already ordered */ 7264 double estimatedCost; /* Estimated cost of using this index */ 7265 /* Fields below are only available in SQLite 3.8.2 and later */ 7266 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7267 /* Fields below are only available in SQLite 3.9.0 and later */ 7268 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7269 /* Fields below are only available in SQLite 3.10.0 and later */ 7270 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7271 }; 7272 7273 /* 7274 ** CAPI3REF: Virtual Table Scan Flags 7275 ** 7276 ** Virtual table implementations are allowed to set the 7277 ** [sqlite3_index_info].idxFlags field to some combination of 7278 ** these bits. 7279 */ 7280 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7281 7282 /* 7283 ** CAPI3REF: Virtual Table Constraint Operator Codes 7284 ** 7285 ** These macros define the allowed values for the 7286 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 7287 ** an operator that is part of a constraint term in the WHERE clause of 7288 ** a query that uses a [virtual table]. 7289 ** 7290 ** ^The left-hand operand of the operator is given by the corresponding 7291 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7292 ** operand is the rowid. 7293 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7294 ** operators have no left-hand operand, and so for those operators the 7295 ** corresponding aConstraint[].iColumn is meaningless and should not be 7296 ** used. 7297 ** 7298 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7299 ** value 255 are reserved to represent functions that are overloaded 7300 ** by the [xFindFunction|xFindFunction method] of the virtual table 7301 ** implementation. 7302 ** 7303 ** The right-hand operands for each constraint might be accessible using 7304 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7305 ** operand is only available if it appears as a single constant literal 7306 ** in the input SQL. If the right-hand operand is another column or an 7307 ** expression (even a constant expression) or a parameter, then the 7308 ** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7309 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7310 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7311 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7312 ** always return SQLITE_NOTFOUND. 7313 ** 7314 ** The collating sequence to be used for comparison can be found using 7315 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7316 ** tables, the collating sequence of constraints does not matter (for example 7317 ** because the constraints are numeric) and so the sqlite3_vtab_collation() 7318 ** interface is no commonly needed. 7319 */ 7320 #define SQLITE_INDEX_CONSTRAINT_EQ 2 7321 #define SQLITE_INDEX_CONSTRAINT_GT 4 7322 #define SQLITE_INDEX_CONSTRAINT_LE 8 7323 #define SQLITE_INDEX_CONSTRAINT_LT 16 7324 #define SQLITE_INDEX_CONSTRAINT_GE 32 7325 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 7326 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 7327 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 7328 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7329 #define SQLITE_INDEX_CONSTRAINT_NE 68 7330 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7331 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7332 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7333 #define SQLITE_INDEX_CONSTRAINT_IS 72 7334 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7335 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7336 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7337 7338 /* 7339 ** CAPI3REF: Register A Virtual Table Implementation 7340 ** METHOD: sqlite3 7341 ** 7342 ** ^These routines are used to register a new [virtual table module] name. 7343 ** ^Module names must be registered before 7344 ** creating a new [virtual table] using the module and before using a 7345 ** preexisting [virtual table] for the module. 7346 ** 7347 ** ^The module name is registered on the [database connection] specified 7348 ** by the first parameter. ^The name of the module is given by the 7349 ** second parameter. ^The third parameter is a pointer to 7350 ** the implementation of the [virtual table module]. ^The fourth 7351 ** parameter is an arbitrary client data pointer that is passed through 7352 ** into the [xCreate] and [xConnect] methods of the virtual table module 7353 ** when a new virtual table is be being created or reinitialized. 7354 ** 7355 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7356 ** is a pointer to a destructor for the pClientData. ^SQLite will 7357 ** invoke the destructor function (if it is not NULL) when SQLite 7358 ** no longer needs the pClientData pointer. ^The destructor will also 7359 ** be invoked if the call to sqlite3_create_module_v2() fails. 7360 ** ^The sqlite3_create_module() 7361 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 7362 ** destructor. 7363 ** 7364 ** ^If the third parameter (the pointer to the sqlite3_module object) is 7365 ** NULL then no new module is created and any existing modules with the 7366 ** same name are dropped. 7367 ** 7368 ** See also: [sqlite3_drop_modules()] 7369 */ 7370 SQLITE_API int sqlite3_create_module( 7371 sqlite3 *db, /* SQLite connection to register module with */ 7372 const char *zName, /* Name of the module */ 7373 const sqlite3_module *p, /* Methods for the module */ 7374 void *pClientData /* Client data for xCreate/xConnect */ 7375 ); 7376 SQLITE_API int sqlite3_create_module_v2( 7377 sqlite3 *db, /* SQLite connection to register module with */ 7378 const char *zName, /* Name of the module */ 7379 const sqlite3_module *p, /* Methods for the module */ 7380 void *pClientData, /* Client data for xCreate/xConnect */ 7381 void(*xDestroy)(void*) /* Module destructor function */ 7382 ); 7383 7384 /* 7385 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7386 ** METHOD: sqlite3 7387 ** 7388 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7389 ** table modules from database connection D except those named on list L. 7390 ** The L parameter must be either NULL or a pointer to an array of pointers 7391 ** to strings where the array is terminated by a single NULL pointer. 7392 ** ^If the L parameter is NULL, then all virtual table modules are removed. 7393 ** 7394 ** See also: [sqlite3_create_module()] 7395 */ 7396 SQLITE_API int sqlite3_drop_modules( 7397 sqlite3 *db, /* Remove modules from this connection */ 7398 const char **azKeep /* Except, do not remove the ones named here */ 7399 ); 7400 7401 /* 7402 ** CAPI3REF: Virtual Table Instance Object 7403 ** KEYWORDS: sqlite3_vtab 7404 ** 7405 ** Every [virtual table module] implementation uses a subclass 7406 ** of this object to describe a particular instance 7407 ** of the [virtual table]. Each subclass will 7408 ** be tailored to the specific needs of the module implementation. 7409 ** The purpose of this superclass is to define certain fields that are 7410 ** common to all module implementations. 7411 ** 7412 ** ^Virtual tables methods can set an error message by assigning a 7413 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7414 ** take care that any prior string is freed by a call to [sqlite3_free()] 7415 ** prior to assigning a new string to zErrMsg. ^After the error message 7416 ** is delivered up to the client application, the string will be automatically 7417 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7418 */ 7419 struct sqlite3_vtab { 7420 const sqlite3_module *pModule; /* The module for this virtual table */ 7421 int nRef; /* Number of open cursors */ 7422 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7423 /* Virtual table implementations will typically add additional fields */ 7424 }; 7425 7426 /* 7427 ** CAPI3REF: Virtual Table Cursor Object 7428 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7429 ** 7430 ** Every [virtual table module] implementation uses a subclass of the 7431 ** following structure to describe cursors that point into the 7432 ** [virtual table] and are used 7433 ** to loop through the virtual table. Cursors are created using the 7434 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7435 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7436 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7437 ** of the module. Each module implementation will define 7438 ** the content of a cursor structure to suit its own needs. 7439 ** 7440 ** This superclass exists in order to define fields of the cursor that 7441 ** are common to all implementations. 7442 */ 7443 struct sqlite3_vtab_cursor { 7444 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7445 /* Virtual table implementations will typically add additional fields */ 7446 }; 7447 7448 /* 7449 ** CAPI3REF: Declare The Schema Of A Virtual Table 7450 ** 7451 ** ^The [xCreate] and [xConnect] methods of a 7452 ** [virtual table module] call this interface 7453 ** to declare the format (the names and datatypes of the columns) of 7454 ** the virtual tables they implement. 7455 */ 7456 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7457 7458 /* 7459 ** CAPI3REF: Overload A Function For A Virtual Table 7460 ** METHOD: sqlite3 7461 ** 7462 ** ^(Virtual tables can provide alternative implementations of functions 7463 ** using the [xFindFunction] method of the [virtual table module]. 7464 ** But global versions of those functions 7465 ** must exist in order to be overloaded.)^ 7466 ** 7467 ** ^(This API makes sure a global version of a function with a particular 7468 ** name and number of parameters exists. If no such function exists 7469 ** before this API is called, a new function is created.)^ ^The implementation 7470 ** of the new function always causes an exception to be thrown. So 7471 ** the new function is not good for anything by itself. Its only 7472 ** purpose is to be a placeholder function that can be overloaded 7473 ** by a [virtual table]. 7474 */ 7475 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7476 7477 /* 7478 ** The interface to the virtual-table mechanism defined above (back up 7479 ** to a comment remarkably similar to this one) is currently considered 7480 ** to be experimental. The interface might change in incompatible ways. 7481 ** If this is a problem for you, do not use the interface at this time. 7482 ** 7483 ** When the virtual-table mechanism stabilizes, we will declare the 7484 ** interface fixed, support it indefinitely, and remove this comment. 7485 */ 7486 7487 /* 7488 ** CAPI3REF: A Handle To An Open BLOB 7489 ** KEYWORDS: {BLOB handle} {BLOB handles} 7490 ** 7491 ** An instance of this object represents an open BLOB on which 7492 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7493 ** ^Objects of this type are created by [sqlite3_blob_open()] 7494 ** and destroyed by [sqlite3_blob_close()]. 7495 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7496 ** can be used to read or write small subsections of the BLOB. 7497 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7498 */ 7499 typedef struct sqlite3_blob sqlite3_blob; 7500 7501 /* 7502 ** CAPI3REF: Open A BLOB For Incremental I/O 7503 ** METHOD: sqlite3 7504 ** CONSTRUCTOR: sqlite3_blob 7505 ** 7506 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7507 ** in row iRow, column zColumn, table zTable in database zDb; 7508 ** in other words, the same BLOB that would be selected by: 7509 ** 7510 ** <pre> 7511 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7512 ** </pre>)^ 7513 ** 7514 ** ^(Parameter zDb is not the filename that contains the database, but 7515 ** rather the symbolic name of the database. For attached databases, this is 7516 ** the name that appears after the AS keyword in the [ATTACH] statement. 7517 ** For the main database file, the database name is "main". For TEMP 7518 ** tables, the database name is "temp".)^ 7519 ** 7520 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 7521 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 7522 ** read-only access. 7523 ** 7524 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7525 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7526 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7527 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7528 ** on *ppBlob after this function it returns. 7529 ** 7530 ** This function fails with SQLITE_ERROR if any of the following are true: 7531 ** <ul> 7532 ** <li> ^(Database zDb does not exist)^, 7533 ** <li> ^(Table zTable does not exist within database zDb)^, 7534 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7535 ** <li> ^(Column zColumn does not exist)^, 7536 ** <li> ^(Row iRow is not present in the table)^, 7537 ** <li> ^(The specified column of row iRow contains a value that is not 7538 ** a TEXT or BLOB value)^, 7539 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7540 ** constraint and the blob is being opened for read/write access)^, 7541 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7542 ** column zColumn is part of a [child key] definition and the blob is 7543 ** being opened for read/write access)^. 7544 ** </ul> 7545 ** 7546 ** ^Unless it returns SQLITE_MISUSE, this function sets the 7547 ** [database connection] error code and message accessible via 7548 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7549 ** 7550 ** A BLOB referenced by sqlite3_blob_open() may be read using the 7551 ** [sqlite3_blob_read()] interface and modified by using 7552 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7553 ** different row of the same table using the [sqlite3_blob_reopen()] 7554 ** interface. However, the column, table, or database of a [BLOB handle] 7555 ** cannot be changed after the [BLOB handle] is opened. 7556 ** 7557 ** ^(If the row that a BLOB handle points to is modified by an 7558 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7559 ** then the BLOB handle is marked as "expired". 7560 ** This is true if any column of the row is changed, even a column 7561 ** other than the one the BLOB handle is open on.)^ 7562 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7563 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7564 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 7565 ** rolled back by the expiration of the BLOB. Such changes will eventually 7566 ** commit if the transaction continues to completion.)^ 7567 ** 7568 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7569 ** the opened blob. ^The size of a blob may not be changed by this 7570 ** interface. Use the [UPDATE] SQL command to change the size of a 7571 ** blob. 7572 ** 7573 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7574 ** and the built-in [zeroblob] SQL function may be used to create a 7575 ** zero-filled blob to read or write using the incremental-blob interface. 7576 ** 7577 ** To avoid a resource leak, every open [BLOB handle] should eventually 7578 ** be released by a call to [sqlite3_blob_close()]. 7579 ** 7580 ** See also: [sqlite3_blob_close()], 7581 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7582 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7583 */ 7584 SQLITE_API int sqlite3_blob_open( 7585 sqlite3*, 7586 const char *zDb, 7587 const char *zTable, 7588 const char *zColumn, 7589 sqlite3_int64 iRow, 7590 int flags, 7591 sqlite3_blob **ppBlob 7592 ); 7593 7594 /* 7595 ** CAPI3REF: Move a BLOB Handle to a New Row 7596 ** METHOD: sqlite3_blob 7597 ** 7598 ** ^This function is used to move an existing [BLOB handle] so that it points 7599 ** to a different row of the same database table. ^The new row is identified 7600 ** by the rowid value passed as the second argument. Only the row can be 7601 ** changed. ^The database, table and column on which the blob handle is open 7602 ** remain the same. Moving an existing [BLOB handle] to a new row is 7603 ** faster than closing the existing handle and opening a new one. 7604 ** 7605 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7606 ** it must exist and there must be either a blob or text value stored in 7607 ** the nominated column.)^ ^If the new row is not present in the table, or if 7608 ** it does not contain a blob or text value, or if another error occurs, an 7609 ** SQLite error code is returned and the blob handle is considered aborted. 7610 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7611 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7612 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7613 ** always returns zero. 7614 ** 7615 ** ^This function sets the database handle error code and message. 7616 */ 7617 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7618 7619 /* 7620 ** CAPI3REF: Close A BLOB Handle 7621 ** DESTRUCTOR: sqlite3_blob 7622 ** 7623 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7624 ** unconditionally. Even if this routine returns an error code, the 7625 ** handle is still closed.)^ 7626 ** 7627 ** ^If the blob handle being closed was opened for read-write access, and if 7628 ** the database is in auto-commit mode and there are no other open read-write 7629 ** blob handles or active write statements, the current transaction is 7630 ** committed. ^If an error occurs while committing the transaction, an error 7631 ** code is returned and the transaction rolled back. 7632 ** 7633 ** Calling this function with an argument that is not a NULL pointer or an 7634 ** open blob handle results in undefined behaviour. ^Calling this routine 7635 ** with a null pointer (such as would be returned by a failed call to 7636 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7637 ** is passed a valid open blob handle, the values returned by the 7638 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7639 */ 7640 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7641 7642 /* 7643 ** CAPI3REF: Return The Size Of An Open BLOB 7644 ** METHOD: sqlite3_blob 7645 ** 7646 ** ^Returns the size in bytes of the BLOB accessible via the 7647 ** successfully opened [BLOB handle] in its only argument. ^The 7648 ** incremental blob I/O routines can only read or overwriting existing 7649 ** blob content; they cannot change the size of a blob. 7650 ** 7651 ** This routine only works on a [BLOB handle] which has been created 7652 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7653 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7654 ** to this routine results in undefined and probably undesirable behavior. 7655 */ 7656 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7657 7658 /* 7659 ** CAPI3REF: Read Data From A BLOB Incrementally 7660 ** METHOD: sqlite3_blob 7661 ** 7662 ** ^(This function is used to read data from an open [BLOB handle] into a 7663 ** caller-supplied buffer. N bytes of data are copied into buffer Z 7664 ** from the open BLOB, starting at offset iOffset.)^ 7665 ** 7666 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7667 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7668 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 7669 ** ^The size of the blob (and hence the maximum value of N+iOffset) 7670 ** can be determined using the [sqlite3_blob_bytes()] interface. 7671 ** 7672 ** ^An attempt to read from an expired [BLOB handle] fails with an 7673 ** error code of [SQLITE_ABORT]. 7674 ** 7675 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7676 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7677 ** 7678 ** This routine only works on a [BLOB handle] which has been created 7679 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7680 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7681 ** to this routine results in undefined and probably undesirable behavior. 7682 ** 7683 ** See also: [sqlite3_blob_write()]. 7684 */ 7685 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7686 7687 /* 7688 ** CAPI3REF: Write Data Into A BLOB Incrementally 7689 ** METHOD: sqlite3_blob 7690 ** 7691 ** ^(This function is used to write data into an open [BLOB handle] from a 7692 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 7693 ** into the open BLOB, starting at offset iOffset.)^ 7694 ** 7695 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7696 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 7697 ** ^Unless SQLITE_MISUSE is returned, this function sets the 7698 ** [database connection] error code and message accessible via 7699 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7700 ** 7701 ** ^If the [BLOB handle] passed as the first argument was not opened for 7702 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7703 ** this function returns [SQLITE_READONLY]. 7704 ** 7705 ** This function may only modify the contents of the BLOB; it is 7706 ** not possible to increase the size of a BLOB using this API. 7707 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 7708 ** [SQLITE_ERROR] is returned and no data is written. The size of the 7709 ** BLOB (and hence the maximum value of N+iOffset) can be determined 7710 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7711 ** than zero [SQLITE_ERROR] is returned and no data is written. 7712 ** 7713 ** ^An attempt to write to an expired [BLOB handle] fails with an 7714 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7715 ** before the [BLOB handle] expired are not rolled back by the 7716 ** expiration of the handle, though of course those changes might 7717 ** have been overwritten by the statement that expired the BLOB handle 7718 ** or by other independent statements. 7719 ** 7720 ** This routine only works on a [BLOB handle] which has been created 7721 ** by a prior successful call to [sqlite3_blob_open()] and which has not 7722 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7723 ** to this routine results in undefined and probably undesirable behavior. 7724 ** 7725 ** See also: [sqlite3_blob_read()]. 7726 */ 7727 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7728 7729 /* 7730 ** CAPI3REF: Virtual File System Objects 7731 ** 7732 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7733 ** that SQLite uses to interact 7734 ** with the underlying operating system. Most SQLite builds come with a 7735 ** single default VFS that is appropriate for the host computer. 7736 ** New VFSes can be registered and existing VFSes can be unregistered. 7737 ** The following interfaces are provided. 7738 ** 7739 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7740 ** ^Names are case sensitive. 7741 ** ^Names are zero-terminated UTF-8 strings. 7742 ** ^If there is no match, a NULL pointer is returned. 7743 ** ^If zVfsName is NULL then the default VFS is returned. 7744 ** 7745 ** ^New VFSes are registered with sqlite3_vfs_register(). 7746 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7747 ** ^The same VFS can be registered multiple times without injury. 7748 ** ^To make an existing VFS into the default VFS, register it again 7749 ** with the makeDflt flag set. If two different VFSes with the 7750 ** same name are registered, the behavior is undefined. If a 7751 ** VFS is registered with a name that is NULL or an empty string, 7752 ** then the behavior is undefined. 7753 ** 7754 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7755 ** ^(If the default VFS is unregistered, another VFS is chosen as 7756 ** the default. The choice for the new VFS is arbitrary.)^ 7757 */ 7758 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7759 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7760 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7761 7762 /* 7763 ** CAPI3REF: Mutexes 7764 ** 7765 ** The SQLite core uses these routines for thread 7766 ** synchronization. Though they are intended for internal 7767 ** use by SQLite, code that links against SQLite is 7768 ** permitted to use any of these routines. 7769 ** 7770 ** The SQLite source code contains multiple implementations 7771 ** of these mutex routines. An appropriate implementation 7772 ** is selected automatically at compile-time. The following 7773 ** implementations are available in the SQLite core: 7774 ** 7775 ** <ul> 7776 ** <li> SQLITE_MUTEX_PTHREADS 7777 ** <li> SQLITE_MUTEX_W32 7778 ** <li> SQLITE_MUTEX_NOOP 7779 ** </ul> 7780 ** 7781 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 7782 ** that does no real locking and is appropriate for use in 7783 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7784 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7785 ** and Windows. 7786 ** 7787 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7788 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7789 ** implementation is included with the library. In this case the 7790 ** application must supply a custom mutex implementation using the 7791 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7792 ** before calling sqlite3_initialize() or any other public sqlite3_ 7793 ** function that calls sqlite3_initialize(). 7794 ** 7795 ** ^The sqlite3_mutex_alloc() routine allocates a new 7796 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7797 ** routine returns NULL if it is unable to allocate the requested 7798 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 7799 ** integer constants: 7800 ** 7801 ** <ul> 7802 ** <li> SQLITE_MUTEX_FAST 7803 ** <li> SQLITE_MUTEX_RECURSIVE 7804 ** <li> SQLITE_MUTEX_STATIC_MAIN 7805 ** <li> SQLITE_MUTEX_STATIC_MEM 7806 ** <li> SQLITE_MUTEX_STATIC_OPEN 7807 ** <li> SQLITE_MUTEX_STATIC_PRNG 7808 ** <li> SQLITE_MUTEX_STATIC_LRU 7809 ** <li> SQLITE_MUTEX_STATIC_PMEM 7810 ** <li> SQLITE_MUTEX_STATIC_APP1 7811 ** <li> SQLITE_MUTEX_STATIC_APP2 7812 ** <li> SQLITE_MUTEX_STATIC_APP3 7813 ** <li> SQLITE_MUTEX_STATIC_VFS1 7814 ** <li> SQLITE_MUTEX_STATIC_VFS2 7815 ** <li> SQLITE_MUTEX_STATIC_VFS3 7816 ** </ul> 7817 ** 7818 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7819 ** cause sqlite3_mutex_alloc() to create 7820 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7821 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7822 ** The mutex implementation does not need to make a distinction 7823 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7824 ** not want to. SQLite will only request a recursive mutex in 7825 ** cases where it really needs one. If a faster non-recursive mutex 7826 ** implementation is available on the host platform, the mutex subsystem 7827 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 7828 ** 7829 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7830 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7831 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 7832 ** used by the current version of SQLite. Future versions of SQLite 7833 ** may add additional static mutexes. Static mutexes are for internal 7834 ** use by SQLite only. Applications that use SQLite mutexes should 7835 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7836 ** SQLITE_MUTEX_RECURSIVE. 7837 ** 7838 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7839 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7840 ** returns a different mutex on every call. ^For the static 7841 ** mutex types, the same mutex is returned on every call that has 7842 ** the same type number. 7843 ** 7844 ** ^The sqlite3_mutex_free() routine deallocates a previously 7845 ** allocated dynamic mutex. Attempting to deallocate a static 7846 ** mutex results in undefined behavior. 7847 ** 7848 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7849 ** to enter a mutex. ^If another thread is already within the mutex, 7850 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7851 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7852 ** upon successful entry. ^(Mutexes created using 7853 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7854 ** In such cases, the 7855 ** mutex must be exited an equal number of times before another thread 7856 ** can enter.)^ If the same thread tries to enter any mutex other 7857 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7858 ** 7859 ** ^(Some systems (for example, Windows 95) do not support the operation 7860 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7861 ** will always return SQLITE_BUSY. The SQLite core only ever uses 7862 ** sqlite3_mutex_try() as an optimization so this is acceptable 7863 ** behavior.)^ 7864 ** 7865 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 7866 ** previously entered by the same thread. The behavior 7867 ** is undefined if the mutex is not currently entered by the 7868 ** calling thread or is not currently allocated. 7869 ** 7870 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7871 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7872 ** behave as no-ops. 7873 ** 7874 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7875 */ 7876 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7877 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7878 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7879 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7880 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7881 7882 /* 7883 ** CAPI3REF: Mutex Methods Object 7884 ** 7885 ** An instance of this structure defines the low-level routines 7886 ** used to allocate and use mutexes. 7887 ** 7888 ** Usually, the default mutex implementations provided by SQLite are 7889 ** sufficient, however the application has the option of substituting a custom 7890 ** implementation for specialized deployments or systems for which SQLite 7891 ** does not provide a suitable implementation. In this case, the application 7892 ** creates and populates an instance of this structure to pass 7893 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7894 ** Additionally, an instance of this structure can be used as an 7895 ** output variable when querying the system for the current mutex 7896 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7897 ** 7898 ** ^The xMutexInit method defined by this structure is invoked as 7899 ** part of system initialization by the sqlite3_initialize() function. 7900 ** ^The xMutexInit routine is called by SQLite exactly once for each 7901 ** effective call to [sqlite3_initialize()]. 7902 ** 7903 ** ^The xMutexEnd method defined by this structure is invoked as 7904 ** part of system shutdown by the sqlite3_shutdown() function. The 7905 ** implementation of this method is expected to release all outstanding 7906 ** resources obtained by the mutex methods implementation, especially 7907 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7908 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7909 ** 7910 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7911 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7912 ** xMutexNotheld) implement the following interfaces (respectively): 7913 ** 7914 ** <ul> 7915 ** <li> [sqlite3_mutex_alloc()] </li> 7916 ** <li> [sqlite3_mutex_free()] </li> 7917 ** <li> [sqlite3_mutex_enter()] </li> 7918 ** <li> [sqlite3_mutex_try()] </li> 7919 ** <li> [sqlite3_mutex_leave()] </li> 7920 ** <li> [sqlite3_mutex_held()] </li> 7921 ** <li> [sqlite3_mutex_notheld()] </li> 7922 ** </ul>)^ 7923 ** 7924 ** The only difference is that the public sqlite3_XXX functions enumerated 7925 ** above silently ignore any invocations that pass a NULL pointer instead 7926 ** of a valid mutex handle. The implementations of the methods defined 7927 ** by this structure are not required to handle this case. The results 7928 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7929 ** (i.e. it is acceptable to provide an implementation that segfaults if 7930 ** it is passed a NULL pointer). 7931 ** 7932 ** The xMutexInit() method must be threadsafe. It must be harmless to 7933 ** invoke xMutexInit() multiple times within the same process and without 7934 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7935 ** xMutexInit() must be no-ops. 7936 ** 7937 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7938 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7939 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7940 ** memory allocation for a fast or recursive mutex. 7941 ** 7942 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7943 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7944 ** If xMutexInit fails in any way, it is expected to clean up after itself 7945 ** prior to returning. 7946 */ 7947 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7948 struct sqlite3_mutex_methods { 7949 int (*xMutexInit)(void); 7950 int (*xMutexEnd)(void); 7951 sqlite3_mutex *(*xMutexAlloc)(int); 7952 void (*xMutexFree)(sqlite3_mutex *); 7953 void (*xMutexEnter)(sqlite3_mutex *); 7954 int (*xMutexTry)(sqlite3_mutex *); 7955 void (*xMutexLeave)(sqlite3_mutex *); 7956 int (*xMutexHeld)(sqlite3_mutex *); 7957 int (*xMutexNotheld)(sqlite3_mutex *); 7958 }; 7959 7960 /* 7961 ** CAPI3REF: Mutex Verification Routines 7962 ** 7963 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7964 ** are intended for use inside assert() statements. The SQLite core 7965 ** never uses these routines except inside an assert() and applications 7966 ** are advised to follow the lead of the core. The SQLite core only 7967 ** provides implementations for these routines when it is compiled 7968 ** with the SQLITE_DEBUG flag. External mutex implementations 7969 ** are only required to provide these routines if SQLITE_DEBUG is 7970 ** defined and if NDEBUG is not defined. 7971 ** 7972 ** These routines should return true if the mutex in their argument 7973 ** is held or not held, respectively, by the calling thread. 7974 ** 7975 ** The implementation is not required to provide versions of these 7976 ** routines that actually work. If the implementation does not provide working 7977 ** versions of these routines, it should at least provide stubs that always 7978 ** return true so that one does not get spurious assertion failures. 7979 ** 7980 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7981 ** the routine should return 1. This seems counter-intuitive since 7982 ** clearly the mutex cannot be held if it does not exist. But 7983 ** the reason the mutex does not exist is because the build is not 7984 ** using mutexes. And we do not want the assert() containing the 7985 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7986 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7987 ** interface should also return 1 when given a NULL pointer. 7988 */ 7989 #ifndef NDEBUG 7990 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7991 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7992 #endif 7993 7994 /* 7995 ** CAPI3REF: Mutex Types 7996 ** 7997 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7998 ** which is one of these integer constants. 7999 ** 8000 ** The set of static mutexes may change from one SQLite release to the 8001 ** next. Applications that override the built-in mutex logic must be 8002 ** prepared to accommodate additional static mutexes. 8003 */ 8004 #define SQLITE_MUTEX_FAST 0 8005 #define SQLITE_MUTEX_RECURSIVE 1 8006 #define SQLITE_MUTEX_STATIC_MAIN 2 8007 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 8008 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 8009 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 8010 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 8011 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 8012 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 8013 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 8014 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 8015 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 8016 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8017 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8018 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8019 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8020 8021 /* Legacy compatibility: */ 8022 #define SQLITE_MUTEX_STATIC_MASTER 2 8023 8024 8025 /* 8026 ** CAPI3REF: Retrieve the mutex for a database connection 8027 ** METHOD: sqlite3 8028 ** 8029 ** ^This interface returns a pointer the [sqlite3_mutex] object that 8030 ** serializes access to the [database connection] given in the argument 8031 ** when the [threading mode] is Serialized. 8032 ** ^If the [threading mode] is Single-thread or Multi-thread then this 8033 ** routine returns a NULL pointer. 8034 */ 8035 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8036 8037 /* 8038 ** CAPI3REF: Low-Level Control Of Database Files 8039 ** METHOD: sqlite3 8040 ** KEYWORDS: {file control} 8041 ** 8042 ** ^The [sqlite3_file_control()] interface makes a direct call to the 8043 ** xFileControl method for the [sqlite3_io_methods] object associated 8044 ** with a particular database identified by the second argument. ^The 8045 ** name of the database is "main" for the main database or "temp" for the 8046 ** TEMP database, or the name that appears after the AS keyword for 8047 ** databases that are added using the [ATTACH] SQL command. 8048 ** ^A NULL pointer can be used in place of "main" to refer to the 8049 ** main database file. 8050 ** ^The third and fourth parameters to this routine 8051 ** are passed directly through to the second and third parameters of 8052 ** the xFileControl method. ^The return value of the xFileControl 8053 ** method becomes the return value of this routine. 8054 ** 8055 ** A few opcodes for [sqlite3_file_control()] are handled directly 8056 ** by the SQLite core and never invoke the 8057 ** sqlite3_io_methods.xFileControl method. 8058 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8059 ** a pointer to the underlying [sqlite3_file] object to be written into 8060 ** the space pointed to by the 4th parameter. The 8061 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8062 ** the [sqlite3_file] object associated with the journal file instead of 8063 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8064 ** a pointer to the underlying [sqlite3_vfs] object for the file. 8065 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8066 ** from the pager. 8067 ** 8068 ** ^If the second parameter (zDbName) does not match the name of any 8069 ** open database file, then SQLITE_ERROR is returned. ^This error 8070 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 8071 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 8072 ** also return SQLITE_ERROR. There is no way to distinguish between 8073 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8074 ** xFileControl method. 8075 ** 8076 ** See also: [file control opcodes] 8077 */ 8078 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8079 8080 /* 8081 ** CAPI3REF: Testing Interface 8082 ** 8083 ** ^The sqlite3_test_control() interface is used to read out internal 8084 ** state of SQLite and to inject faults into SQLite for testing 8085 ** purposes. ^The first parameter is an operation code that determines 8086 ** the number, meaning, and operation of all subsequent parameters. 8087 ** 8088 ** This interface is not for use by applications. It exists solely 8089 ** for verifying the correct operation of the SQLite library. Depending 8090 ** on how the SQLite library is compiled, this interface might not exist. 8091 ** 8092 ** The details of the operation codes, their meanings, the parameters 8093 ** they take, and what they do are all subject to change without notice. 8094 ** Unlike most of the SQLite API, this function is not guaranteed to 8095 ** operate consistently from one release to the next. 8096 */ 8097 SQLITE_API int sqlite3_test_control(int op, ...); 8098 8099 /* 8100 ** CAPI3REF: Testing Interface Operation Codes 8101 ** 8102 ** These constants are the valid operation code parameters used 8103 ** as the first argument to [sqlite3_test_control()]. 8104 ** 8105 ** These parameters and their meanings are subject to change 8106 ** without notice. These values are for testing purposes only. 8107 ** Applications should not use any of these parameters or the 8108 ** [sqlite3_test_control()] interface. 8109 */ 8110 #define SQLITE_TESTCTRL_FIRST 5 8111 #define SQLITE_TESTCTRL_PRNG_SAVE 5 8112 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 8113 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8114 #define SQLITE_TESTCTRL_BITVEC_TEST 8 8115 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 8116 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8117 #define SQLITE_TESTCTRL_PENDING_BYTE 11 8118 #define SQLITE_TESTCTRL_ASSERT 12 8119 #define SQLITE_TESTCTRL_ALWAYS 13 8120 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8121 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8122 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8123 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8124 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8125 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8126 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8127 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8128 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8129 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8130 #define SQLITE_TESTCTRL_BYTEORDER 22 8131 #define SQLITE_TESTCTRL_ISINIT 23 8132 #define SQLITE_TESTCTRL_SORTER_MMAP 24 8133 #define SQLITE_TESTCTRL_IMPOSTER 25 8134 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8135 #define SQLITE_TESTCTRL_RESULT_INTREAL 27 8136 #define SQLITE_TESTCTRL_PRNG_SEED 28 8137 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8138 #define SQLITE_TESTCTRL_SEEK_COUNT 30 8139 #define SQLITE_TESTCTRL_TRACEFLAGS 31 8140 #define SQLITE_TESTCTRL_TUNE 32 8141 #define SQLITE_TESTCTRL_LOGEST 33 8142 #define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ 8143 8144 /* 8145 ** CAPI3REF: SQL Keyword Checking 8146 ** 8147 ** These routines provide access to the set of SQL language keywords 8148 ** recognized by SQLite. Applications can uses these routines to determine 8149 ** whether or not a specific identifier needs to be escaped (for example, 8150 ** by enclosing in double-quotes) so as not to confuse the parser. 8151 ** 8152 ** The sqlite3_keyword_count() interface returns the number of distinct 8153 ** keywords understood by SQLite. 8154 ** 8155 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8156 ** makes *Z point to that keyword expressed as UTF8 and writes the number 8157 ** of bytes in the keyword into *L. The string that *Z points to is not 8158 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8159 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8160 ** or L are NULL or invalid pointers then calls to 8161 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8162 ** 8163 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8164 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8165 ** if it is and zero if not. 8166 ** 8167 ** The parser used by SQLite is forgiving. It is often possible to use 8168 ** a keyword as an identifier as long as such use does not result in a 8169 ** parsing ambiguity. For example, the statement 8170 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8171 ** creates a new table named "BEGIN" with three columns named 8172 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8173 ** using keywords as identifiers. Common techniques used to avoid keyword 8174 ** name collisions include: 8175 ** <ul> 8176 ** <li> Put all identifier names inside double-quotes. This is the official 8177 ** SQL way to escape identifier names. 8178 ** <li> Put identifier names inside [...]. This is not standard SQL, 8179 ** but it is what SQL Server does and so lots of programmers use this 8180 ** technique. 8181 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8182 ** with "Z". 8183 ** <li> Include a digit somewhere in every identifier name. 8184 ** </ul> 8185 ** 8186 ** Note that the number of keywords understood by SQLite can depend on 8187 ** compile-time options. For example, "VACUUM" is not a keyword if 8188 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8189 ** new keywords may be added to future releases of SQLite. 8190 */ 8191 SQLITE_API int sqlite3_keyword_count(void); 8192 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8193 SQLITE_API int sqlite3_keyword_check(const char*,int); 8194 8195 /* 8196 ** CAPI3REF: Dynamic String Object 8197 ** KEYWORDS: {dynamic string} 8198 ** 8199 ** An instance of the sqlite3_str object contains a dynamically-sized 8200 ** string under construction. 8201 ** 8202 ** The lifecycle of an sqlite3_str object is as follows: 8203 ** <ol> 8204 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8205 ** <li> ^Text is appended to the sqlite3_str object using various 8206 ** methods, such as [sqlite3_str_appendf()]. 8207 ** <li> ^The sqlite3_str object is destroyed and the string it created 8208 ** is returned using the [sqlite3_str_finish()] interface. 8209 ** </ol> 8210 */ 8211 typedef struct sqlite3_str sqlite3_str; 8212 8213 /* 8214 ** CAPI3REF: Create A New Dynamic String Object 8215 ** CONSTRUCTOR: sqlite3_str 8216 ** 8217 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 8218 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8219 ** [sqlite3_str_new()] must be freed by a subsequent call to 8220 ** [sqlite3_str_finish(X)]. 8221 ** 8222 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8223 ** valid [sqlite3_str] object, though in the event of an out-of-memory 8224 ** error the returned object might be a special singleton that will 8225 ** silently reject new text, always return SQLITE_NOMEM from 8226 ** [sqlite3_str_errcode()], always return 0 for 8227 ** [sqlite3_str_length()], and always return NULL from 8228 ** [sqlite3_str_finish(X)]. It is always safe to use the value 8229 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8230 ** to any of the other [sqlite3_str] methods. 8231 ** 8232 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8233 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8234 ** length of the string contained in the [sqlite3_str] object will be 8235 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8236 ** of [SQLITE_MAX_LENGTH]. 8237 */ 8238 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8239 8240 /* 8241 ** CAPI3REF: Finalize A Dynamic String 8242 ** DESTRUCTOR: sqlite3_str 8243 ** 8244 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8245 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8246 ** that contains the constructed string. The calling application should 8247 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8248 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8249 ** errors were encountered during construction of the string. ^The 8250 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8251 ** string in [sqlite3_str] object X is zero bytes long. 8252 */ 8253 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8254 8255 /* 8256 ** CAPI3REF: Add Content To A Dynamic String 8257 ** METHOD: sqlite3_str 8258 ** 8259 ** These interfaces add content to an sqlite3_str object previously obtained 8260 ** from [sqlite3_str_new()]. 8261 ** 8262 ** ^The [sqlite3_str_appendf(X,F,...)] and 8263 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8264 ** functionality of SQLite to append formatted text onto the end of 8265 ** [sqlite3_str] object X. 8266 ** 8267 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8268 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 8269 ** S must contain at least N non-zero bytes of content. To append a 8270 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8271 ** method instead. 8272 ** 8273 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8274 ** zero-terminated string S onto the end of [sqlite3_str] object X. 8275 ** 8276 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8277 ** single-byte character C onto the end of [sqlite3_str] object X. 8278 ** ^This method can be used, for example, to add whitespace indentation. 8279 ** 8280 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 8281 ** inside [sqlite3_str] object X back to zero bytes in length. 8282 ** 8283 ** These methods do not return a result code. ^If an error occurs, that fact 8284 ** is recorded in the [sqlite3_str] object and can be recovered by a 8285 ** subsequent call to [sqlite3_str_errcode(X)]. 8286 */ 8287 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8288 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8289 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8290 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8291 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8292 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8293 8294 /* 8295 ** CAPI3REF: Status Of A Dynamic String 8296 ** METHOD: sqlite3_str 8297 ** 8298 ** These interfaces return the current status of an [sqlite3_str] object. 8299 ** 8300 ** ^If any prior errors have occurred while constructing the dynamic string 8301 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8302 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8303 ** [SQLITE_NOMEM] following any out-of-memory error, or 8304 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8305 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8306 ** 8307 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8308 ** of the dynamic string under construction in [sqlite3_str] object X. 8309 ** ^The length returned by [sqlite3_str_length(X)] does not include the 8310 ** zero-termination byte. 8311 ** 8312 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8313 ** content of the dynamic string under construction in X. The value 8314 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8315 ** and might be freed or altered by any subsequent method on the same 8316 ** [sqlite3_str] object. Applications must not used the pointer returned 8317 ** [sqlite3_str_value(X)] after any subsequent method call on the same 8318 ** object. ^Applications may change the content of the string returned 8319 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8320 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8321 ** write any byte after any subsequent sqlite3_str method call. 8322 */ 8323 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8324 SQLITE_API int sqlite3_str_length(sqlite3_str*); 8325 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8326 8327 /* 8328 ** CAPI3REF: SQLite Runtime Status 8329 ** 8330 ** ^These interfaces are used to retrieve runtime status information 8331 ** about the performance of SQLite, and optionally to reset various 8332 ** highwater marks. ^The first argument is an integer code for 8333 ** the specific parameter to measure. ^(Recognized integer codes 8334 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 8335 ** ^The current value of the parameter is returned into *pCurrent. 8336 ** ^The highest recorded value is returned in *pHighwater. ^If the 8337 ** resetFlag is true, then the highest record value is reset after 8338 ** *pHighwater is written. ^(Some parameters do not record the highest 8339 ** value. For those parameters 8340 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8341 ** ^(Other parameters record only the highwater mark and not the current 8342 ** value. For these latter parameters nothing is written into *pCurrent.)^ 8343 ** 8344 ** ^The sqlite3_status() and sqlite3_status64() routines return 8345 ** SQLITE_OK on success and a non-zero [error code] on failure. 8346 ** 8347 ** If either the current value or the highwater mark is too large to 8348 ** be represented by a 32-bit integer, then the values returned by 8349 ** sqlite3_status() are undefined. 8350 ** 8351 ** See also: [sqlite3_db_status()] 8352 */ 8353 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8354 SQLITE_API int sqlite3_status64( 8355 int op, 8356 sqlite3_int64 *pCurrent, 8357 sqlite3_int64 *pHighwater, 8358 int resetFlag 8359 ); 8360 8361 8362 /* 8363 ** CAPI3REF: Status Parameters 8364 ** KEYWORDS: {status parameters} 8365 ** 8366 ** These integer constants designate various run-time status parameters 8367 ** that can be returned by [sqlite3_status()]. 8368 ** 8369 ** <dl> 8370 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8371 ** <dd>This parameter is the current amount of memory checked out 8372 ** using [sqlite3_malloc()], either directly or indirectly. The 8373 ** figure includes calls made to [sqlite3_malloc()] by the application 8374 ** and internal memory usage by the SQLite library. Auxiliary page-cache 8375 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8376 ** this parameter. The amount returned is the sum of the allocation 8377 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8378 ** 8379 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8380 ** <dd>This parameter records the largest memory allocation request 8381 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8382 ** internal equivalents). Only the value returned in the 8383 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8384 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8385 ** 8386 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8387 ** <dd>This parameter records the number of separate memory allocations 8388 ** currently checked out.</dd>)^ 8389 ** 8390 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8391 ** <dd>This parameter returns the number of pages used out of the 8392 ** [pagecache memory allocator] that was configured using 8393 ** [SQLITE_CONFIG_PAGECACHE]. The 8394 ** value returned is in pages, not in bytes.</dd>)^ 8395 ** 8396 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8397 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8398 ** <dd>This parameter returns the number of bytes of page cache 8399 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8400 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 8401 ** returned value includes allocations that overflowed because they 8402 ** where too large (they were larger than the "sz" parameter to 8403 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8404 ** no space was left in the page cache.</dd>)^ 8405 ** 8406 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8407 ** <dd>This parameter records the largest memory allocation request 8408 ** handed to the [pagecache memory allocator]. Only the value returned in the 8409 ** *pHighwater parameter to [sqlite3_status()] is of interest. 8410 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 8411 ** 8412 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8413 ** <dd>No longer used.</dd> 8414 ** 8415 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8416 ** <dd>No longer used.</dd> 8417 ** 8418 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8419 ** <dd>No longer used.</dd> 8420 ** 8421 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8422 ** <dd>The *pHighwater parameter records the deepest parser stack. 8423 ** The *pCurrent value is undefined. The *pHighwater value is only 8424 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8425 ** </dl> 8426 ** 8427 ** New status parameters may be added from time to time. 8428 */ 8429 #define SQLITE_STATUS_MEMORY_USED 0 8430 #define SQLITE_STATUS_PAGECACHE_USED 1 8431 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8432 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8433 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8434 #define SQLITE_STATUS_MALLOC_SIZE 5 8435 #define SQLITE_STATUS_PARSER_STACK 6 8436 #define SQLITE_STATUS_PAGECACHE_SIZE 7 8437 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8438 #define SQLITE_STATUS_MALLOC_COUNT 9 8439 8440 /* 8441 ** CAPI3REF: Database Connection Status 8442 ** METHOD: sqlite3 8443 ** 8444 ** ^This interface is used to retrieve runtime status information 8445 ** about a single [database connection]. ^The first argument is the 8446 ** database connection object to be interrogated. ^The second argument 8447 ** is an integer constant, taken from the set of 8448 ** [SQLITE_DBSTATUS options], that 8449 ** determines the parameter to interrogate. The set of 8450 ** [SQLITE_DBSTATUS options] is likely 8451 ** to grow in future releases of SQLite. 8452 ** 8453 ** ^The current value of the requested parameter is written into *pCur 8454 ** and the highest instantaneous value is written into *pHiwtr. ^If 8455 ** the resetFlg is true, then the highest instantaneous value is 8456 ** reset back down to the current value. 8457 ** 8458 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8459 ** non-zero [error code] on failure. 8460 ** 8461 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8462 */ 8463 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8464 8465 /* 8466 ** CAPI3REF: Status Parameters for database connections 8467 ** KEYWORDS: {SQLITE_DBSTATUS options} 8468 ** 8469 ** These constants are the available integer "verbs" that can be passed as 8470 ** the second argument to the [sqlite3_db_status()] interface. 8471 ** 8472 ** New verbs may be added in future releases of SQLite. Existing verbs 8473 ** might be discontinued. Applications should check the return code from 8474 ** [sqlite3_db_status()] to make sure that the call worked. 8475 ** The [sqlite3_db_status()] interface will return a non-zero error code 8476 ** if a discontinued or unsupported verb is invoked. 8477 ** 8478 ** <dl> 8479 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8480 ** <dd>This parameter returns the number of lookaside memory slots currently 8481 ** checked out.</dd>)^ 8482 ** 8483 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8484 ** <dd>This parameter returns the number of malloc attempts that were 8485 ** satisfied using lookaside memory. Only the high-water value is meaningful; 8486 ** the current value is always zero.)^ 8487 ** 8488 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8489 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8490 ** <dd>This parameter returns the number malloc attempts that might have 8491 ** been satisfied using lookaside memory but failed due to the amount of 8492 ** memory requested being larger than the lookaside slot size. 8493 ** Only the high-water value is meaningful; 8494 ** the current value is always zero.)^ 8495 ** 8496 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8497 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8498 ** <dd>This parameter returns the number malloc attempts that might have 8499 ** been satisfied using lookaside memory but failed due to all lookaside 8500 ** memory already being in use. 8501 ** Only the high-water value is meaningful; 8502 ** the current value is always zero.)^ 8503 ** 8504 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8505 ** <dd>This parameter returns the approximate number of bytes of heap 8506 ** memory used by all pager caches associated with the database connection.)^ 8507 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8508 ** 8509 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8510 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8511 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8512 ** pager cache is shared between two or more connections the bytes of heap 8513 ** memory used by that pager cache is divided evenly between the attached 8514 ** connections.)^ In other words, if none of the pager caches associated 8515 ** with the database connection are shared, this request returns the same 8516 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8517 ** shared, the value returned by this call will be smaller than that returned 8518 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8519 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8520 ** 8521 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8522 ** <dd>This parameter returns the approximate number of bytes of heap 8523 ** memory used to store the schema for all databases associated 8524 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8525 ** ^The full amount of memory used by the schemas is reported, even if the 8526 ** schema memory is shared with other database connections due to 8527 ** [shared cache mode] being enabled. 8528 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8529 ** 8530 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8531 ** <dd>This parameter returns the approximate number of bytes of heap 8532 ** and lookaside memory used by all prepared statements associated with 8533 ** the database connection.)^ 8534 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8535 ** </dd> 8536 ** 8537 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8538 ** <dd>This parameter returns the number of pager cache hits that have 8539 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8540 ** is always 0. 8541 ** </dd> 8542 ** 8543 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8544 ** <dd>This parameter returns the number of pager cache misses that have 8545 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8546 ** is always 0. 8547 ** </dd> 8548 ** 8549 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8550 ** <dd>This parameter returns the number of dirty cache entries that have 8551 ** been written to disk. Specifically, the number of pages written to the 8552 ** wal file in wal mode databases, or the number of pages written to the 8553 ** database file in rollback mode databases. Any pages written as part of 8554 ** transaction rollback or database recovery operations are not included. 8555 ** If an IO or other error occurs while writing a page to disk, the effect 8556 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8557 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8558 ** </dd> 8559 ** 8560 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8561 ** <dd>This parameter returns the number of dirty cache entries that have 8562 ** been written to disk in the middle of a transaction due to the page 8563 ** cache overflowing. Transactions are more efficient if they are written 8564 ** to disk all at once. When pages spill mid-transaction, that introduces 8565 ** additional overhead. This parameter can be used help identify 8566 ** inefficiencies that can be resolved by increasing the cache size. 8567 ** </dd> 8568 ** 8569 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8570 ** <dd>This parameter returns zero for the current value if and only if 8571 ** all foreign key constraints (deferred or immediate) have been 8572 ** resolved.)^ ^The highwater mark is always 0. 8573 ** </dd> 8574 ** </dl> 8575 */ 8576 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8577 #define SQLITE_DBSTATUS_CACHE_USED 1 8578 #define SQLITE_DBSTATUS_SCHEMA_USED 2 8579 #define SQLITE_DBSTATUS_STMT_USED 3 8580 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8581 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8582 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8583 #define SQLITE_DBSTATUS_CACHE_HIT 7 8584 #define SQLITE_DBSTATUS_CACHE_MISS 8 8585 #define SQLITE_DBSTATUS_CACHE_WRITE 9 8586 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 8587 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8588 #define SQLITE_DBSTATUS_CACHE_SPILL 12 8589 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8590 8591 8592 /* 8593 ** CAPI3REF: Prepared Statement Status 8594 ** METHOD: sqlite3_stmt 8595 ** 8596 ** ^(Each prepared statement maintains various 8597 ** [SQLITE_STMTSTATUS counters] that measure the number 8598 ** of times it has performed specific operations.)^ These counters can 8599 ** be used to monitor the performance characteristics of the prepared 8600 ** statements. For example, if the number of table steps greatly exceeds 8601 ** the number of table searches or result rows, that would tend to indicate 8602 ** that the prepared statement is using a full table scan rather than 8603 ** an index. 8604 ** 8605 ** ^(This interface is used to retrieve and reset counter values from 8606 ** a [prepared statement]. The first argument is the prepared statement 8607 ** object to be interrogated. The second argument 8608 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8609 ** to be interrogated.)^ 8610 ** ^The current value of the requested counter is returned. 8611 ** ^If the resetFlg is true, then the counter is reset to zero after this 8612 ** interface call returns. 8613 ** 8614 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8615 */ 8616 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8617 8618 /* 8619 ** CAPI3REF: Status Parameters for prepared statements 8620 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8621 ** 8622 ** These preprocessor macros define integer codes that name counter 8623 ** values associated with the [sqlite3_stmt_status()] interface. 8624 ** The meanings of the various counters are as follows: 8625 ** 8626 ** <dl> 8627 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8628 ** <dd>^This is the number of times that SQLite has stepped forward in 8629 ** a table as part of a full table scan. Large numbers for this counter 8630 ** may indicate opportunities for performance improvement through 8631 ** careful use of indices.</dd> 8632 ** 8633 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8634 ** <dd>^This is the number of sort operations that have occurred. 8635 ** A non-zero value in this counter may indicate an opportunity to 8636 ** improvement performance through careful use of indices.</dd> 8637 ** 8638 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8639 ** <dd>^This is the number of rows inserted into transient indices that 8640 ** were created automatically in order to help joins run faster. 8641 ** A non-zero value in this counter may indicate an opportunity to 8642 ** improvement performance by adding permanent indices that do not 8643 ** need to be reinitialized each time the statement is run.</dd> 8644 ** 8645 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8646 ** <dd>^This is the number of virtual machine operations executed 8647 ** by the prepared statement if that number is less than or equal 8648 ** to 2147483647. The number of virtual machine operations can be 8649 ** used as a proxy for the total work done by the prepared statement. 8650 ** If the number of virtual machine operations exceeds 2147483647 8651 ** then the value returned by this statement status code is undefined. 8652 ** 8653 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8654 ** <dd>^This is the number of times that the prepare statement has been 8655 ** automatically regenerated due to schema changes or changes to 8656 ** [bound parameters] that might affect the query plan. 8657 ** 8658 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8659 ** <dd>^This is the number of times that the prepared statement has 8660 ** been run. A single "run" for the purposes of this counter is one 8661 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8662 ** The counter is incremented on the first [sqlite3_step()] call of each 8663 ** cycle. 8664 ** 8665 ** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8666 ** [[SQLITE_STMTSTATUS_FILTER HIT]] 8667 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8668 ** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8669 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8670 ** step was bypassed because a Bloom filter returned not-found. The 8671 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8672 ** times that the Bloom filter returned a find, and thus the join step 8673 ** had to be processed as normal. 8674 ** 8675 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8676 ** <dd>^This is the approximate number of bytes of heap memory 8677 ** used to store the prepared statement. ^This value is not actually 8678 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8679 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8680 ** </dd> 8681 ** </dl> 8682 */ 8683 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8684 #define SQLITE_STMTSTATUS_SORT 2 8685 #define SQLITE_STMTSTATUS_AUTOINDEX 3 8686 #define SQLITE_STMTSTATUS_VM_STEP 4 8687 #define SQLITE_STMTSTATUS_REPREPARE 5 8688 #define SQLITE_STMTSTATUS_RUN 6 8689 #define SQLITE_STMTSTATUS_FILTER_MISS 7 8690 #define SQLITE_STMTSTATUS_FILTER_HIT 8 8691 #define SQLITE_STMTSTATUS_MEMUSED 99 8692 8693 /* 8694 ** CAPI3REF: Custom Page Cache Object 8695 ** 8696 ** The sqlite3_pcache type is opaque. It is implemented by 8697 ** the pluggable module. The SQLite core has no knowledge of 8698 ** its size or internal structure and never deals with the 8699 ** sqlite3_pcache object except by holding and passing pointers 8700 ** to the object. 8701 ** 8702 ** See [sqlite3_pcache_methods2] for additional information. 8703 */ 8704 typedef struct sqlite3_pcache sqlite3_pcache; 8705 8706 /* 8707 ** CAPI3REF: Custom Page Cache Object 8708 ** 8709 ** The sqlite3_pcache_page object represents a single page in the 8710 ** page cache. The page cache will allocate instances of this 8711 ** object. Various methods of the page cache use pointers to instances 8712 ** of this object as parameters or as their return value. 8713 ** 8714 ** See [sqlite3_pcache_methods2] for additional information. 8715 */ 8716 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8717 struct sqlite3_pcache_page { 8718 void *pBuf; /* The content of the page */ 8719 void *pExtra; /* Extra information associated with the page */ 8720 }; 8721 8722 /* 8723 ** CAPI3REF: Application Defined Page Cache. 8724 ** KEYWORDS: {page cache} 8725 ** 8726 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8727 ** register an alternative page cache implementation by passing in an 8728 ** instance of the sqlite3_pcache_methods2 structure.)^ 8729 ** In many applications, most of the heap memory allocated by 8730 ** SQLite is used for the page cache. 8731 ** By implementing a 8732 ** custom page cache using this API, an application can better control 8733 ** the amount of memory consumed by SQLite, the way in which 8734 ** that memory is allocated and released, and the policies used to 8735 ** determine exactly which parts of a database file are cached and for 8736 ** how long. 8737 ** 8738 ** The alternative page cache mechanism is an 8739 ** extreme measure that is only needed by the most demanding applications. 8740 ** The built-in page cache is recommended for most uses. 8741 ** 8742 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8743 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8744 ** the application may discard the parameter after the call to 8745 ** [sqlite3_config()] returns.)^ 8746 ** 8747 ** [[the xInit() page cache method]] 8748 ** ^(The xInit() method is called once for each effective 8749 ** call to [sqlite3_initialize()])^ 8750 ** (usually only once during the lifetime of the process). ^(The xInit() 8751 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8752 ** The intent of the xInit() method is to set up global data structures 8753 ** required by the custom page cache implementation. 8754 ** ^(If the xInit() method is NULL, then the 8755 ** built-in default page cache is used instead of the application defined 8756 ** page cache.)^ 8757 ** 8758 ** [[the xShutdown() page cache method]] 8759 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8760 ** It can be used to clean up 8761 ** any outstanding resources before process shutdown, if required. 8762 ** ^The xShutdown() method may be NULL. 8763 ** 8764 ** ^SQLite automatically serializes calls to the xInit method, 8765 ** so the xInit method need not be threadsafe. ^The 8766 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 8767 ** not need to be threadsafe either. All other methods must be threadsafe 8768 ** in multithreaded applications. 8769 ** 8770 ** ^SQLite will never invoke xInit() more than once without an intervening 8771 ** call to xShutdown(). 8772 ** 8773 ** [[the xCreate() page cache methods]] 8774 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 8775 ** SQLite will typically create one cache instance for each open database file, 8776 ** though this is not guaranteed. ^The 8777 ** first parameter, szPage, is the size in bytes of the pages that must 8778 ** be allocated by the cache. ^szPage will always a power of two. ^The 8779 ** second parameter szExtra is a number of bytes of extra storage 8780 ** associated with each page cache entry. ^The szExtra parameter will 8781 ** a number less than 250. SQLite will use the 8782 ** extra szExtra bytes on each page to store metadata about the underlying 8783 ** database page on disk. The value passed into szExtra depends 8784 ** on the SQLite version, the target platform, and how SQLite was compiled. 8785 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8786 ** created will be used to cache database pages of a file stored on disk, or 8787 ** false if it is used for an in-memory database. The cache implementation 8788 ** does not have to do anything special based with the value of bPurgeable; 8789 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8790 ** never invoke xUnpin() except to deliberately delete a page. 8791 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8792 ** false will always have the "discard" flag set to true. 8793 ** ^Hence, a cache created with bPurgeable false will 8794 ** never contain any unpinned pages. 8795 ** 8796 ** [[the xCachesize() page cache method]] 8797 ** ^(The xCachesize() method may be called at any time by SQLite to set the 8798 ** suggested maximum cache-size (number of pages stored by) the cache 8799 ** instance passed as the first argument. This is the value configured using 8800 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8801 ** parameter, the implementation is not required to do anything with this 8802 ** value; it is advisory only. 8803 ** 8804 ** [[the xPagecount() page cache methods]] 8805 ** The xPagecount() method must return the number of pages currently 8806 ** stored in the cache, both pinned and unpinned. 8807 ** 8808 ** [[the xFetch() page cache methods]] 8809 ** The xFetch() method locates a page in the cache and returns a pointer to 8810 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8811 ** The pBuf element of the returned sqlite3_pcache_page object will be a 8812 ** pointer to a buffer of szPage bytes used to store the content of a 8813 ** single database page. The pExtra element of sqlite3_pcache_page will be 8814 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 8815 ** for each entry in the page cache. 8816 ** 8817 ** The page to be fetched is determined by the key. ^The minimum key value 8818 ** is 1. After it has been retrieved using xFetch, the page is considered 8819 ** to be "pinned". 8820 ** 8821 ** If the requested page is already in the page cache, then the page cache 8822 ** implementation must return a pointer to the page buffer with its content 8823 ** intact. If the requested page is not already in the cache, then the 8824 ** cache implementation should use the value of the createFlag 8825 ** parameter to help it determined what action to take: 8826 ** 8827 ** <table border=1 width=85% align=center> 8828 ** <tr><th> createFlag <th> Behavior when page is not already in cache 8829 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8830 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8831 ** Otherwise return NULL. 8832 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8833 ** NULL if allocating a new page is effectively impossible. 8834 ** </table> 8835 ** 8836 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8837 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 8838 ** failed.)^ In between the xFetch() calls, SQLite may 8839 ** attempt to unpin one or more cache pages by spilling the content of 8840 ** pinned pages to disk and synching the operating system disk cache. 8841 ** 8842 ** [[the xUnpin() page cache method]] 8843 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8844 ** as its second argument. If the third parameter, discard, is non-zero, 8845 ** then the page must be evicted from the cache. 8846 ** ^If the discard parameter is 8847 ** zero, then the page may be discarded or retained at the discretion of 8848 ** page cache implementation. ^The page cache implementation 8849 ** may choose to evict unpinned pages at any time. 8850 ** 8851 ** The cache must not perform any reference counting. A single 8852 ** call to xUnpin() unpins the page regardless of the number of prior calls 8853 ** to xFetch(). 8854 ** 8855 ** [[the xRekey() page cache methods]] 8856 ** The xRekey() method is used to change the key value associated with the 8857 ** page passed as the second argument. If the cache 8858 ** previously contains an entry associated with newKey, it must be 8859 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8860 ** to be pinned. 8861 ** 8862 ** When SQLite calls the xTruncate() method, the cache must discard all 8863 ** existing cache entries with page numbers (keys) greater than or equal 8864 ** to the value of the iLimit parameter passed to xTruncate(). If any 8865 ** of these pages are pinned, they are implicitly unpinned, meaning that 8866 ** they can be safely discarded. 8867 ** 8868 ** [[the xDestroy() page cache method]] 8869 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8870 ** All resources associated with the specified cache should be freed. ^After 8871 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8872 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8873 ** functions. 8874 ** 8875 ** [[the xShrink() page cache method]] 8876 ** ^SQLite invokes the xShrink() method when it wants the page cache to 8877 ** free up as much of heap memory as possible. The page cache implementation 8878 ** is not obligated to free any memory, but well-behaved implementations should 8879 ** do their best. 8880 */ 8881 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8882 struct sqlite3_pcache_methods2 { 8883 int iVersion; 8884 void *pArg; 8885 int (*xInit)(void*); 8886 void (*xShutdown)(void*); 8887 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8888 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8889 int (*xPagecount)(sqlite3_pcache*); 8890 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8891 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8892 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8893 unsigned oldKey, unsigned newKey); 8894 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8895 void (*xDestroy)(sqlite3_pcache*); 8896 void (*xShrink)(sqlite3_pcache*); 8897 }; 8898 8899 /* 8900 ** This is the obsolete pcache_methods object that has now been replaced 8901 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8902 ** retained in the header file for backwards compatibility only. 8903 */ 8904 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8905 struct sqlite3_pcache_methods { 8906 void *pArg; 8907 int (*xInit)(void*); 8908 void (*xShutdown)(void*); 8909 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8910 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8911 int (*xPagecount)(sqlite3_pcache*); 8912 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8913 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8914 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8915 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8916 void (*xDestroy)(sqlite3_pcache*); 8917 }; 8918 8919 8920 /* 8921 ** CAPI3REF: Online Backup Object 8922 ** 8923 ** The sqlite3_backup object records state information about an ongoing 8924 ** online backup operation. ^The sqlite3_backup object is created by 8925 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8926 ** [sqlite3_backup_finish()]. 8927 ** 8928 ** See Also: [Using the SQLite Online Backup API] 8929 */ 8930 typedef struct sqlite3_backup sqlite3_backup; 8931 8932 /* 8933 ** CAPI3REF: Online Backup API. 8934 ** 8935 ** The backup API copies the content of one database into another. 8936 ** It is useful either for creating backups of databases or 8937 ** for copying in-memory databases to or from persistent files. 8938 ** 8939 ** See Also: [Using the SQLite Online Backup API] 8940 ** 8941 ** ^SQLite holds a write transaction open on the destination database file 8942 ** for the duration of the backup operation. 8943 ** ^The source database is read-locked only while it is being read; 8944 ** it is not locked continuously for the entire backup operation. 8945 ** ^Thus, the backup may be performed on a live source database without 8946 ** preventing other database connections from 8947 ** reading or writing to the source database while the backup is underway. 8948 ** 8949 ** ^(To perform a backup operation: 8950 ** <ol> 8951 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8952 ** backup, 8953 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8954 ** the data between the two databases, and finally 8955 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8956 ** associated with the backup operation. 8957 ** </ol>)^ 8958 ** There should be exactly one call to sqlite3_backup_finish() for each 8959 ** successful call to sqlite3_backup_init(). 8960 ** 8961 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8962 ** 8963 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8964 ** [database connection] associated with the destination database 8965 ** and the database name, respectively. 8966 ** ^The database name is "main" for the main database, "temp" for the 8967 ** temporary database, or the name specified after the AS keyword in 8968 ** an [ATTACH] statement for an attached database. 8969 ** ^The S and M arguments passed to 8970 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8971 ** and database name of the source database, respectively. 8972 ** ^The source and destination [database connections] (parameters S and D) 8973 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8974 ** an error. 8975 ** 8976 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8977 ** there is already a read or read-write transaction open on the 8978 ** destination database. 8979 ** 8980 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8981 ** returned and an error code and error message are stored in the 8982 ** destination [database connection] D. 8983 ** ^The error code and message for the failed call to sqlite3_backup_init() 8984 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8985 ** [sqlite3_errmsg16()] functions. 8986 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8987 ** [sqlite3_backup] object. 8988 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8989 ** sqlite3_backup_finish() functions to perform the specified backup 8990 ** operation. 8991 ** 8992 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8993 ** 8994 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8995 ** the source and destination databases specified by [sqlite3_backup] object B. 8996 ** ^If N is negative, all remaining source pages are copied. 8997 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8998 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8999 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 9000 ** from source to destination, then it returns [SQLITE_DONE]. 9001 ** ^If an error occurs while running sqlite3_backup_step(B,N), 9002 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 9003 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 9004 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 9005 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 9006 ** 9007 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 9008 ** <ol> 9009 ** <li> the destination database was opened read-only, or 9010 ** <li> the destination database is using write-ahead-log journaling 9011 ** and the destination and source page sizes differ, or 9012 ** <li> the destination database is an in-memory database and the 9013 ** destination and source page sizes differ. 9014 ** </ol>)^ 9015 ** 9016 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9017 ** the [sqlite3_busy_handler | busy-handler function] 9018 ** is invoked (if one is specified). ^If the 9019 ** busy-handler returns non-zero before the lock is available, then 9020 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9021 ** sqlite3_backup_step() can be retried later. ^If the source 9022 ** [database connection] 9023 ** is being used to write to the source database when sqlite3_backup_step() 9024 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9025 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 9026 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9027 ** [SQLITE_READONLY] is returned, then 9028 ** there is no point in retrying the call to sqlite3_backup_step(). These 9029 ** errors are considered fatal.)^ The application must accept 9030 ** that the backup operation has failed and pass the backup operation handle 9031 ** to the sqlite3_backup_finish() to release associated resources. 9032 ** 9033 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9034 ** on the destination file. ^The exclusive lock is not released until either 9035 ** sqlite3_backup_finish() is called or the backup operation is complete 9036 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9037 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 9038 ** lasts for the duration of the sqlite3_backup_step() call. 9039 ** ^Because the source database is not locked between calls to 9040 ** sqlite3_backup_step(), the source database may be modified mid-way 9041 ** through the backup process. ^If the source database is modified by an 9042 ** external process or via a database connection other than the one being 9043 ** used by the backup operation, then the backup will be automatically 9044 ** restarted by the next call to sqlite3_backup_step(). ^If the source 9045 ** database is modified by the using the same database connection as is used 9046 ** by the backup operation, then the backup database is automatically 9047 ** updated at the same time. 9048 ** 9049 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9050 ** 9051 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9052 ** application wishes to abandon the backup operation, the application 9053 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9054 ** ^The sqlite3_backup_finish() interfaces releases all 9055 ** resources associated with the [sqlite3_backup] object. 9056 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9057 ** active write-transaction on the destination database is rolled back. 9058 ** The [sqlite3_backup] object is invalid 9059 ** and may not be used following a call to sqlite3_backup_finish(). 9060 ** 9061 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9062 ** sqlite3_backup_step() errors occurred, regardless or whether or not 9063 ** sqlite3_backup_step() completed. 9064 ** ^If an out-of-memory condition or IO error occurred during any prior 9065 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9066 ** sqlite3_backup_finish() returns the corresponding [error code]. 9067 ** 9068 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9069 ** is not a permanent error and does not affect the return value of 9070 ** sqlite3_backup_finish(). 9071 ** 9072 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9073 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9074 ** 9075 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 9076 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9077 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9078 ** in the source database at the conclusion of the most recent 9079 ** sqlite3_backup_step(). 9080 ** ^(The values returned by these functions are only updated by 9081 ** sqlite3_backup_step(). If the source database is modified in a way that 9082 ** changes the size of the source database or the number of pages remaining, 9083 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 9084 ** and sqlite3_backup_remaining() until after the next 9085 ** sqlite3_backup_step().)^ 9086 ** 9087 ** <b>Concurrent Usage of Database Handles</b> 9088 ** 9089 ** ^The source [database connection] may be used by the application for other 9090 ** purposes while a backup operation is underway or being initialized. 9091 ** ^If SQLite is compiled and configured to support threadsafe database 9092 ** connections, then the source database connection may be used concurrently 9093 ** from within other threads. 9094 ** 9095 ** However, the application must guarantee that the destination 9096 ** [database connection] is not passed to any other API (by any thread) after 9097 ** sqlite3_backup_init() is called and before the corresponding call to 9098 ** sqlite3_backup_finish(). SQLite does not currently check to see 9099 ** if the application incorrectly accesses the destination [database connection] 9100 ** and so no error code is reported, but the operations may malfunction 9101 ** nevertheless. Use of the destination database connection while a 9102 ** backup is in progress might also cause a mutex deadlock. 9103 ** 9104 ** If running in [shared cache mode], the application must 9105 ** guarantee that the shared cache used by the destination database 9106 ** is not accessed while the backup is running. In practice this means 9107 ** that the application must guarantee that the disk file being 9108 ** backed up to is not accessed by any connection within the process, 9109 ** not just the specific connection that was passed to sqlite3_backup_init(). 9110 ** 9111 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9112 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9113 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9114 ** APIs are not strictly speaking threadsafe. If they are invoked at the 9115 ** same time as another thread is invoking sqlite3_backup_step() it is 9116 ** possible that they return invalid values. 9117 */ 9118 SQLITE_API sqlite3_backup *sqlite3_backup_init( 9119 sqlite3 *pDest, /* Destination database handle */ 9120 const char *zDestName, /* Destination database name */ 9121 sqlite3 *pSource, /* Source database handle */ 9122 const char *zSourceName /* Source database name */ 9123 ); 9124 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9125 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9126 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9127 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9128 9129 /* 9130 ** CAPI3REF: Unlock Notification 9131 ** METHOD: sqlite3 9132 ** 9133 ** ^When running in shared-cache mode, a database operation may fail with 9134 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9135 ** individual tables within the shared-cache cannot be obtained. See 9136 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9137 ** ^This API may be used to register a callback that SQLite will invoke 9138 ** when the connection currently holding the required lock relinquishes it. 9139 ** ^This API is only available if the library was compiled with the 9140 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9141 ** 9142 ** See Also: [Using the SQLite Unlock Notification Feature]. 9143 ** 9144 ** ^Shared-cache locks are released when a database connection concludes 9145 ** its current transaction, either by committing it or rolling it back. 9146 ** 9147 ** ^When a connection (known as the blocked connection) fails to obtain a 9148 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9149 ** identity of the database connection (the blocking connection) that 9150 ** has locked the required resource is stored internally. ^After an 9151 ** application receives an SQLITE_LOCKED error, it may call the 9152 ** sqlite3_unlock_notify() method with the blocked connection handle as 9153 ** the first argument to register for a callback that will be invoked 9154 ** when the blocking connections current transaction is concluded. ^The 9155 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9156 ** call that concludes the blocking connection's transaction. 9157 ** 9158 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9159 ** there is a chance that the blocking connection will have already 9160 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9161 ** If this happens, then the specified callback is invoked immediately, 9162 ** from within the call to sqlite3_unlock_notify().)^ 9163 ** 9164 ** ^If the blocked connection is attempting to obtain a write-lock on a 9165 ** shared-cache table, and more than one other connection currently holds 9166 ** a read-lock on the same table, then SQLite arbitrarily selects one of 9167 ** the other connections to use as the blocking connection. 9168 ** 9169 ** ^(There may be at most one unlock-notify callback registered by a 9170 ** blocked connection. If sqlite3_unlock_notify() is called when the 9171 ** blocked connection already has a registered unlock-notify callback, 9172 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9173 ** called with a NULL pointer as its second argument, then any existing 9174 ** unlock-notify callback is canceled. ^The blocked connections 9175 ** unlock-notify callback may also be canceled by closing the blocked 9176 ** connection using [sqlite3_close()]. 9177 ** 9178 ** The unlock-notify callback is not reentrant. If an application invokes 9179 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 9180 ** crash or deadlock may be the result. 9181 ** 9182 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9183 ** returns SQLITE_OK. 9184 ** 9185 ** <b>Callback Invocation Details</b> 9186 ** 9187 ** When an unlock-notify callback is registered, the application provides a 9188 ** single void* pointer that is passed to the callback when it is invoked. 9189 ** However, the signature of the callback function allows SQLite to pass 9190 ** it an array of void* context pointers. The first argument passed to 9191 ** an unlock-notify callback is a pointer to an array of void* pointers, 9192 ** and the second is the number of entries in the array. 9193 ** 9194 ** When a blocking connection's transaction is concluded, there may be 9195 ** more than one blocked connection that has registered for an unlock-notify 9196 ** callback. ^If two or more such blocked connections have specified the 9197 ** same callback function, then instead of invoking the callback function 9198 ** multiple times, it is invoked once with the set of void* context pointers 9199 ** specified by the blocked connections bundled together into an array. 9200 ** This gives the application an opportunity to prioritize any actions 9201 ** related to the set of unblocked database connections. 9202 ** 9203 ** <b>Deadlock Detection</b> 9204 ** 9205 ** Assuming that after registering for an unlock-notify callback a 9206 ** database waits for the callback to be issued before taking any further 9207 ** action (a reasonable assumption), then using this API may cause the 9208 ** application to deadlock. For example, if connection X is waiting for 9209 ** connection Y's transaction to be concluded, and similarly connection 9210 ** Y is waiting on connection X's transaction, then neither connection 9211 ** will proceed and the system may remain deadlocked indefinitely. 9212 ** 9213 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9214 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 9215 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9216 ** unlock-notify callback is registered. The system is said to be in 9217 ** a deadlocked state if connection A has registered for an unlock-notify 9218 ** callback on the conclusion of connection B's transaction, and connection 9219 ** B has itself registered for an unlock-notify callback when connection 9220 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 9221 ** the system is also considered to be deadlocked if connection B has 9222 ** registered for an unlock-notify callback on the conclusion of connection 9223 ** C's transaction, where connection C is waiting on connection A. ^Any 9224 ** number of levels of indirection are allowed. 9225 ** 9226 ** <b>The "DROP TABLE" Exception</b> 9227 ** 9228 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9229 ** always appropriate to call sqlite3_unlock_notify(). There is however, 9230 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9231 ** SQLite checks if there are any currently executing SELECT statements 9232 ** that belong to the same connection. If there are, SQLITE_LOCKED is 9233 ** returned. In this case there is no "blocking connection", so invoking 9234 ** sqlite3_unlock_notify() results in the unlock-notify callback being 9235 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 9236 ** or "DROP INDEX" query, an infinite loop might be the result. 9237 ** 9238 ** One way around this problem is to check the extended error code returned 9239 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9240 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9241 ** the special "DROP TABLE/INDEX" case, the extended error code is just 9242 ** SQLITE_LOCKED.)^ 9243 */ 9244 SQLITE_API int sqlite3_unlock_notify( 9245 sqlite3 *pBlocked, /* Waiting connection */ 9246 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9247 void *pNotifyArg /* Argument to pass to xNotify */ 9248 ); 9249 9250 9251 /* 9252 ** CAPI3REF: String Comparison 9253 ** 9254 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9255 ** and extensions to compare the contents of two buffers containing UTF-8 9256 ** strings in a case-independent fashion, using the same definition of "case 9257 ** independence" that SQLite uses internally when comparing identifiers. 9258 */ 9259 SQLITE_API int sqlite3_stricmp(const char *, const char *); 9260 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9261 9262 /* 9263 ** CAPI3REF: String Globbing 9264 * 9265 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9266 ** string X matches the [GLOB] pattern P. 9267 ** ^The definition of [GLOB] pattern matching used in 9268 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9269 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9270 ** is case sensitive. 9271 ** 9272 ** Note that this routine returns zero on a match and non-zero if the strings 9273 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9274 ** 9275 ** See also: [sqlite3_strlike()]. 9276 */ 9277 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9278 9279 /* 9280 ** CAPI3REF: String LIKE Matching 9281 * 9282 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9283 ** string X matches the [LIKE] pattern P with escape character E. 9284 ** ^The definition of [LIKE] pattern matching used in 9285 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9286 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9287 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9288 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9289 ** insensitive - equivalent upper and lower case ASCII characters match 9290 ** one another. 9291 ** 9292 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9293 ** only ASCII characters are case folded. 9294 ** 9295 ** Note that this routine returns zero on a match and non-zero if the strings 9296 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9297 ** 9298 ** See also: [sqlite3_strglob()]. 9299 */ 9300 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9301 9302 /* 9303 ** CAPI3REF: Error Logging Interface 9304 ** 9305 ** ^The [sqlite3_log()] interface writes a message into the [error log] 9306 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9307 ** ^If logging is enabled, the zFormat string and subsequent arguments are 9308 ** used with [sqlite3_snprintf()] to generate the final output string. 9309 ** 9310 ** The sqlite3_log() interface is intended for use by extensions such as 9311 ** virtual tables, collating functions, and SQL functions. While there is 9312 ** nothing to prevent an application from calling sqlite3_log(), doing so 9313 ** is considered bad form. 9314 ** 9315 ** The zFormat string must not be NULL. 9316 ** 9317 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9318 ** will not use dynamically allocated memory. The log message is stored in 9319 ** a fixed-length buffer on the stack. If the log message is longer than 9320 ** a few hundred characters, it will be truncated to the length of the 9321 ** buffer. 9322 */ 9323 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9324 9325 /* 9326 ** CAPI3REF: Write-Ahead Log Commit Hook 9327 ** METHOD: sqlite3 9328 ** 9329 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 9330 ** is invoked each time data is committed to a database in wal mode. 9331 ** 9332 ** ^(The callback is invoked by SQLite after the commit has taken place and 9333 ** the associated write-lock on the database released)^, so the implementation 9334 ** may read, write or [checkpoint] the database as required. 9335 ** 9336 ** ^The first parameter passed to the callback function when it is invoked 9337 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 9338 ** registering the callback. ^The second is a copy of the database handle. 9339 ** ^The third parameter is the name of the database that was written to - 9340 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9341 ** is the number of pages currently in the write-ahead log file, 9342 ** including those that were just committed. 9343 ** 9344 ** The callback function should normally return [SQLITE_OK]. ^If an error 9345 ** code is returned, that error will propagate back up through the 9346 ** SQLite code base to cause the statement that provoked the callback 9347 ** to report an error, though the commit will have still occurred. If the 9348 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9349 ** that does not correspond to any valid SQLite error code, the results 9350 ** are undefined. 9351 ** 9352 ** A single database handle may have at most a single write-ahead log callback 9353 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9354 ** previously registered write-ahead log callback. ^The return value is 9355 ** a copy of the third parameter from the previous call, if any, or 0. 9356 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9357 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9358 ** overwrite any prior [sqlite3_wal_hook()] settings. 9359 */ 9360 SQLITE_API void *sqlite3_wal_hook( 9361 sqlite3*, 9362 int(*)(void *,sqlite3*,const char*,int), 9363 void* 9364 ); 9365 9366 /* 9367 ** CAPI3REF: Configure an auto-checkpoint 9368 ** METHOD: sqlite3 9369 ** 9370 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9371 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 9372 ** to automatically [checkpoint] 9373 ** after committing a transaction if there are N or 9374 ** more frames in the [write-ahead log] file. ^Passing zero or 9375 ** a negative value as the nFrame parameter disables automatic 9376 ** checkpoints entirely. 9377 ** 9378 ** ^The callback registered by this function replaces any existing callback 9379 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9380 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9381 ** configured by this function. 9382 ** 9383 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9384 ** from SQL. 9385 ** 9386 ** ^Checkpoints initiated by this mechanism are 9387 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9388 ** 9389 ** ^Every new [database connection] defaults to having the auto-checkpoint 9390 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9391 ** pages. The use of this interface 9392 ** is only necessary if the default setting is found to be suboptimal 9393 ** for a particular application. 9394 */ 9395 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9396 9397 /* 9398 ** CAPI3REF: Checkpoint a database 9399 ** METHOD: sqlite3 9400 ** 9401 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9402 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9403 ** 9404 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9405 ** [write-ahead log] for database X on [database connection] D to be 9406 ** transferred into the database file and for the write-ahead log to 9407 ** be reset. See the [checkpointing] documentation for addition 9408 ** information. 9409 ** 9410 ** This interface used to be the only way to cause a checkpoint to 9411 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9412 ** interface was added. This interface is retained for backwards 9413 ** compatibility and as a convenience for applications that need to manually 9414 ** start a callback but which do not need the full power (and corresponding 9415 ** complication) of [sqlite3_wal_checkpoint_v2()]. 9416 */ 9417 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9418 9419 /* 9420 ** CAPI3REF: Checkpoint a database 9421 ** METHOD: sqlite3 9422 ** 9423 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9424 ** operation on database X of [database connection] D in mode M. Status 9425 ** information is written back into integers pointed to by L and C.)^ 9426 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 9427 ** 9428 ** <dl> 9429 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9430 ** ^Checkpoint as many frames as possible without waiting for any database 9431 ** readers or writers to finish, then sync the database file if all frames 9432 ** in the log were checkpointed. ^The [busy-handler callback] 9433 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9434 ** ^On the other hand, passive mode might leave the checkpoint unfinished 9435 ** if there are concurrent readers or writers. 9436 ** 9437 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 9438 ** ^This mode blocks (it invokes the 9439 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 9440 ** database writer and all readers are reading from the most recent database 9441 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 9442 ** database file. ^This mode blocks new database writers while it is pending, 9443 ** but new database readers are allowed to continue unimpeded. 9444 ** 9445 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9446 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9447 ** that after checkpointing the log file it blocks (calls the 9448 ** [busy-handler callback]) 9449 ** until all readers are reading from the database file only. ^This ensures 9450 ** that the next writer will restart the log file from the beginning. 9451 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9452 ** database writer attempts while it is pending, but does not impede readers. 9453 ** 9454 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9455 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9456 ** addition that it also truncates the log file to zero bytes just prior 9457 ** to a successful return. 9458 ** </dl> 9459 ** 9460 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9461 ** the log file or to -1 if the checkpoint could not run because 9462 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9463 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9464 ** log file (including any that were already checkpointed before the function 9465 ** was called) or to -1 if the checkpoint could not run due to an error or 9466 ** because the database is not in WAL mode. ^Note that upon successful 9467 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9468 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9469 ** 9470 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9471 ** any other process is running a checkpoint operation at the same time, the 9472 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9473 ** busy-handler configured, it will not be invoked in this case. 9474 ** 9475 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9476 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9477 ** obtained immediately, and a busy-handler is configured, it is invoked and 9478 ** the writer lock retried until either the busy-handler returns 0 or the lock 9479 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 9480 ** database readers as described above. ^If the busy-handler returns 0 before 9481 ** the writer lock is obtained or while waiting for database readers, the 9482 ** checkpoint operation proceeds from that point in the same way as 9483 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9484 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 9485 ** 9486 ** ^If parameter zDb is NULL or points to a zero length string, then the 9487 ** specified operation is attempted on all WAL databases [attached] to 9488 ** [database connection] db. In this case the 9489 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9490 ** an SQLITE_BUSY error is encountered when processing one or more of the 9491 ** attached WAL databases, the operation is still attempted on any remaining 9492 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9493 ** error occurs while processing an attached database, processing is abandoned 9494 ** and the error code is returned to the caller immediately. ^If no error 9495 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9496 ** databases, SQLITE_OK is returned. 9497 ** 9498 ** ^If database zDb is the name of an attached database that is not in WAL 9499 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9500 ** zDb is not NULL (or a zero length string) and is not the name of any 9501 ** attached database, SQLITE_ERROR is returned to the caller. 9502 ** 9503 ** ^Unless it returns SQLITE_MISUSE, 9504 ** the sqlite3_wal_checkpoint_v2() interface 9505 ** sets the error information that is queried by 9506 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9507 ** 9508 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9509 ** from SQL. 9510 */ 9511 SQLITE_API int sqlite3_wal_checkpoint_v2( 9512 sqlite3 *db, /* Database handle */ 9513 const char *zDb, /* Name of attached database (or NULL) */ 9514 int eMode, /* SQLITE_CHECKPOINT_* value */ 9515 int *pnLog, /* OUT: Size of WAL log in frames */ 9516 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9517 ); 9518 9519 /* 9520 ** CAPI3REF: Checkpoint Mode Values 9521 ** KEYWORDS: {checkpoint mode} 9522 ** 9523 ** These constants define all valid values for the "checkpoint mode" passed 9524 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9525 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9526 ** meaning of each of these checkpoint modes. 9527 */ 9528 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9529 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9530 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9531 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9532 9533 /* 9534 ** CAPI3REF: Virtual Table Interface Configuration 9535 ** 9536 ** This function may be called by either the [xConnect] or [xCreate] method 9537 ** of a [virtual table] implementation to configure 9538 ** various facets of the virtual table interface. 9539 ** 9540 ** If this interface is invoked outside the context of an xConnect or 9541 ** xCreate virtual table method then the behavior is undefined. 9542 ** 9543 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9544 ** [database connection] in which the virtual table is being created and 9545 ** which is passed in as the first argument to the [xConnect] or [xCreate] 9546 ** method that is invoking sqlite3_vtab_config(). The C parameter is one 9547 ** of the [virtual table configuration options]. The presence and meaning 9548 ** of parameters after C depend on which [virtual table configuration option] 9549 ** is used. 9550 */ 9551 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9552 9553 /* 9554 ** CAPI3REF: Virtual Table Configuration Options 9555 ** KEYWORDS: {virtual table configuration options} 9556 ** KEYWORDS: {virtual table configuration option} 9557 ** 9558 ** These macros define the various options to the 9559 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 9560 ** can use to customize and optimize their behavior. 9561 ** 9562 ** <dl> 9563 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9564 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9565 ** <dd>Calls of the form 9566 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9567 ** where X is an integer. If X is zero, then the [virtual table] whose 9568 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9569 ** support constraints. In this configuration (which is the default) if 9570 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9571 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9572 ** specified as part of the users SQL statement, regardless of the actual 9573 ** ON CONFLICT mode specified. 9574 ** 9575 ** If X is non-zero, then the virtual table implementation guarantees 9576 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9577 ** any modifications to internal or persistent data structures have been made. 9578 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9579 ** is able to roll back a statement or database transaction, and abandon 9580 ** or continue processing the current SQL statement as appropriate. 9581 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9582 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9583 ** had been ABORT. 9584 ** 9585 ** Virtual table implementations that are required to handle OR REPLACE 9586 ** must do so within the [xUpdate] method. If a call to the 9587 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9588 ** CONFLICT policy is REPLACE, the virtual table implementation should 9589 ** silently replace the appropriate rows within the xUpdate callback and 9590 ** return SQLITE_OK. Or, if this is not possible, it may return 9591 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9592 ** constraint handling. 9593 ** </dd> 9594 ** 9595 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9596 ** <dd>Calls of the form 9597 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9598 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9599 ** prohibits that virtual table from being used from within triggers and 9600 ** views. 9601 ** </dd> 9602 ** 9603 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9604 ** <dd>Calls of the form 9605 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9606 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9607 ** identify that virtual table as being safe to use from within triggers 9608 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9609 ** virtual table can do no serious harm even if it is controlled by a 9610 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9611 ** flag unless absolutely necessary. 9612 ** </dd> 9613 ** </dl> 9614 */ 9615 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9616 #define SQLITE_VTAB_INNOCUOUS 2 9617 #define SQLITE_VTAB_DIRECTONLY 3 9618 9619 /* 9620 ** CAPI3REF: Determine The Virtual Table Conflict Policy 9621 ** 9622 ** This function may only be called from within a call to the [xUpdate] method 9623 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9624 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9625 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9626 ** of the SQL statement that triggered the call to the [xUpdate] method of the 9627 ** [virtual table]. 9628 */ 9629 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9630 9631 /* 9632 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9633 ** 9634 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9635 ** method of a [virtual table], then it might return true if the 9636 ** column is being fetched as part of an UPDATE operation during which the 9637 ** column value will not change. The virtual table implementation can use 9638 ** this hint as permission to substitute a return value that is less 9639 ** expensive to compute and that the corresponding 9640 ** [xUpdate] method understands as a "no-change" value. 9641 ** 9642 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9643 ** the column is not changed by the UPDATE statement, then the xColumn 9644 ** method can optionally return without setting a result, without calling 9645 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9646 ** In that case, [sqlite3_value_nochange(X)] will return true for the 9647 ** same column in the [xUpdate] method. 9648 ** 9649 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9650 ** implementations should continue to give a correct answer even if the 9651 ** sqlite3_vtab_nochange() interface were to always return false. In the 9652 ** current implementation, the sqlite3_vtab_nochange() interface does always 9653 ** returns false for the enhanced [UPDATE FROM] statement. 9654 */ 9655 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9656 9657 /* 9658 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9659 ** METHOD: sqlite3_index_info 9660 ** 9661 ** This function may only be called from within a call to the [xBestIndex] 9662 ** method of a [virtual table]. This function returns a pointer to a string 9663 ** that is the name of the appropriate collation sequence to use for text 9664 ** comparisons on the constraint identified by its arguments. 9665 ** 9666 ** The first argument must be the pointer to the [sqlite3_index_info] object 9667 ** that is the first parameter to the xBestIndex() method. The second argument 9668 ** must be an index into the aConstraint[] array belonging to the 9669 ** sqlite3_index_info structure passed to xBestIndex. 9670 ** 9671 ** Important: 9672 ** The first parameter must be the same pointer that is passed into the 9673 ** xBestMethod() method. The first parameter may not be a pointer to a 9674 ** different [sqlite3_index_info] object, even an exact copy. 9675 ** 9676 ** The return value is computed as follows: 9677 ** 9678 ** <ol> 9679 ** <li><p> If the constraint comes from a WHERE clause expression that contains 9680 ** a [COLLATE operator], then the name of the collation specified by 9681 ** that COLLATE operator is returned. 9682 ** <li><p> If there is no COLLATE operator, but the column that is the subject 9683 ** of the constraint specifies an alternative collating sequence via 9684 ** a [COLLATE clause] on the column definition within the CREATE TABLE 9685 ** statement that was passed into [sqlite3_declare_vtab()], then the 9686 ** name of that alternative collating sequence is returned. 9687 ** <li><p> Otherwise, "BINARY" is returned. 9688 ** </ol> 9689 */ 9690 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9691 9692 /* 9693 ** CAPI3REF: Determine if a virtual table query is DISTINCT 9694 ** METHOD: sqlite3_index_info 9695 ** 9696 ** This API may only be used from within an [xBestIndex|xBestIndex method] 9697 ** of a [virtual table] implementation. The result of calling this 9698 ** interface from outside of xBestIndex() is undefined and probably harmful. 9699 ** 9700 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9701 ** 3. The integer returned by sqlite3_vtab_distinct() 9702 ** gives the virtual table additional information about how the query 9703 ** planner wants the output to be ordered. As long as the virtual table 9704 ** can meet the ordering requirements of the query planner, it may set 9705 ** the "orderByConsumed" flag. 9706 ** 9707 ** <ol><li value="0"><p> 9708 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9709 ** that the query planner needs the virtual table to return all rows in the 9710 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9711 ** [sqlite3_index_info] object. This is the default expectation. If the 9712 ** virtual table outputs all rows in sorted order, then it is always safe for 9713 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9714 ** the return value from sqlite3_vtab_distinct(). 9715 ** <li value="1"><p> 9716 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9717 ** that the query planner does not need the rows to be returned in sorted order 9718 ** as long as all rows with the same values in all columns identified by the 9719 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9720 ** is doing a GROUP BY. 9721 ** <li value="2"><p> 9722 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9723 ** that the query planner does not need the rows returned in any particular 9724 ** order, as long as rows with the same values in all "aOrderBy" columns 9725 ** are adjacent.)^ ^(Furthermore, only a single row for each particular 9726 ** combination of values in the columns identified by the "aOrderBy" field 9727 ** needs to be returned.)^ ^It is always ok for two or more rows with the same 9728 ** values in all "aOrderBy" columns to be returned, as long as all such rows 9729 ** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9730 ** that have the same value for all columns identified by "aOrderBy". 9731 ** ^However omitting the extra rows is optional. 9732 ** This mode is used for a DISTINCT query. 9733 ** <li value="3"><p> 9734 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9735 ** that the query planner needs only distinct rows but it does need the 9736 ** rows to be sorted.)^ ^The virtual table implementation is free to omit 9737 ** rows that are identical in all aOrderBy columns, if it wants to, but 9738 ** it is not required to omit any rows. This mode is used for queries 9739 ** that have both DISTINCT and ORDER BY clauses. 9740 ** </ol> 9741 ** 9742 ** ^For the purposes of comparing virtual table output values to see if the 9743 ** values are same value for sorting purposes, two NULL values are considered 9744 ** to be the same. In other words, the comparison operator is "IS" 9745 ** (or "IS NOT DISTINCT FROM") and not "==". 9746 ** 9747 ** If a virtual table implementation is unable to meet the requirements 9748 ** specified above, then it must not set the "orderByConsumed" flag in the 9749 ** [sqlite3_index_info] object or an incorrect answer may result. 9750 ** 9751 ** ^A virtual table implementation is always free to return rows in any order 9752 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9753 ** the "orderByConsumed" flag is unset, the query planner will add extra 9754 ** [bytecode] to ensure that the final results returned by the SQL query are 9755 ** ordered correctly. The use of the "orderByConsumed" flag and the 9756 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9757 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9758 ** flag might help queries against a virtual table to run faster. Being 9759 ** overly aggressive and setting the "orderByConsumed" flag when it is not 9760 ** valid to do so, on the other hand, might cause SQLite to return incorrect 9761 ** results. 9762 */ 9763 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9764 9765 /* 9766 ** CAPI3REF: Identify and handle IN constraints in xBestIndex 9767 ** 9768 ** This interface may only be used from within an 9769 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9770 ** The result of invoking this interface from any other context is 9771 ** undefined and probably harmful. 9772 ** 9773 ** ^(A constraint on a virtual table of the form 9774 ** "[IN operator|column IN (...)]" is 9775 ** communicated to the xBestIndex method as a 9776 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9777 ** this constraint, it must set the corresponding 9778 ** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under 9779 ** the usual mode of handling IN operators, SQLite generates [bytecode] 9780 ** that invokes the [xFilter|xFilter() method] once for each value 9781 ** on the right-hand side of the IN operator.)^ Thus the virtual table 9782 ** only sees a single value from the right-hand side of the IN operator 9783 ** at a time. 9784 ** 9785 ** In some cases, however, it would be advantageous for the virtual 9786 ** table to see all values on the right-hand of the IN operator all at 9787 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9788 ** 9789 ** <ol> 9790 ** <li><p> 9791 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9792 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9793 ** is an [IN operator] that can be processed all at once. ^In other words, 9794 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9795 ** by which the virtual table can ask SQLite if all-at-once processing 9796 ** of the IN operator is even possible. 9797 ** 9798 ** <li><p> 9799 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9800 ** to SQLite that the virtual table does or does not want to process 9801 ** the IN operator all-at-once, respectively. ^Thus when the third 9802 ** parameter (F) is non-negative, this interface is the mechanism by 9803 ** which the virtual table tells SQLite how it wants to process the 9804 ** IN operator. 9805 ** </ol> 9806 ** 9807 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9808 ** within the same xBestIndex method call. ^For any given P,N pair, 9809 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9810 ** within the same xBestIndex call. ^If the interface returns true 9811 ** (non-zero), that means that the constraint is an IN operator 9812 ** that can be processed all-at-once. ^If the constraint is not an IN 9813 ** operator or cannot be processed all-at-once, then the interface returns 9814 ** false. 9815 ** 9816 ** ^(All-at-once processing of the IN operator is selected if both of the 9817 ** following conditions are met: 9818 ** 9819 ** <ol> 9820 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9821 ** integer. This is how the virtual table tells SQLite that it wants to 9822 ** use the N-th constraint. 9823 ** 9824 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9825 ** non-negative had F>=1. 9826 ** </ol>)^ 9827 ** 9828 ** ^If either or both of the conditions above are false, then SQLite uses 9829 ** the traditional one-at-a-time processing strategy for the IN constraint. 9830 ** ^If both conditions are true, then the argvIndex-th parameter to the 9831 ** xFilter method will be an [sqlite3_value] that appears to be NULL, 9832 ** but which can be passed to [sqlite3_vtab_in_first()] and 9833 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9834 ** of the IN constraint. 9835 */ 9836 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9837 9838 /* 9839 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9840 ** 9841 ** These interfaces are only useful from within the 9842 ** [xFilter|xFilter() method] of a [virtual table] implementation. 9843 ** The result of invoking these interfaces from any other context 9844 ** is undefined and probably harmful. 9845 ** 9846 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9847 ** sqlite3_vtab_in_next(X,P) must be one of the parameters to the 9848 ** xFilter method which invokes these routines, and specifically 9849 ** a parameter that was previously selected for all-at-once IN constraint 9850 ** processing use the [sqlite3_vtab_in()] interface in the 9851 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 9852 ** an xFilter argument that was selected for all-at-once IN constraint 9853 ** processing, then these routines return [SQLITE_MISUSE])^ or perhaps 9854 ** exhibit some other undefined or harmful behavior. 9855 ** 9856 ** ^(Use these routines to access all values on the right-hand side 9857 ** of the IN constraint using code like the following: 9858 ** 9859 ** <blockquote><pre> 9860 ** for(rc=sqlite3_vtab_in_first(pList, &pVal); 9861 ** rc==SQLITE_OK && pVal 9862 ** rc=sqlite3_vtab_in_next(pList, &pVal) 9863 ** ){ 9864 ** // do something with pVal 9865 ** } 9866 ** if( rc!=SQLITE_OK ){ 9867 ** // an error has occurred 9868 ** } 9869 ** </pre></blockquote>)^ 9870 ** 9871 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 9872 ** routines return SQLITE_OK and set *P to point to the first or next value 9873 ** on the RHS of the IN constraint. ^If there are no more values on the 9874 ** right hand side of the IN constraint, then *P is set to NULL and these 9875 ** routines return [SQLITE_DONE]. ^The return value might be 9876 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 9877 ** 9878 ** The *ppOut values returned by these routines are only valid until the 9879 ** next call to either of these routines or until the end of the xFilter 9880 ** method from which these routines were called. If the virtual table 9881 ** implementation needs to retain the *ppOut values for longer, it must make 9882 ** copies. The *ppOut values are [protected sqlite3_value|protected]. 9883 */ 9884 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 9885 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 9886 9887 /* 9888 ** CAPI3REF: Constraint values in xBestIndex() 9889 ** METHOD: sqlite3_index_info 9890 ** 9891 ** This API may only be used from within the [xBestIndex|xBestIndex method] 9892 ** of a [virtual table] implementation. The result of calling this interface 9893 ** from outside of an xBestIndex method are undefined and probably harmful. 9894 ** 9895 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 9896 ** the [xBestIndex] method of a [virtual table] implementation, with P being 9897 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 9898 ** J being a 0-based index into P->aConstraint[], then this routine 9899 ** attempts to set *V to the value of the right-hand operand of 9900 ** that constraint if the right-hand operand is known. ^If the 9901 ** right-hand operand is not known, then *V is set to a NULL pointer. 9902 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 9903 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 9904 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 9905 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 9906 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 9907 ** something goes wrong. 9908 ** 9909 ** The sqlite3_vtab_rhs_value() interface is usually only successful if 9910 ** the right-hand operand of a constraint is a literal value in the original 9911 ** SQL statement. If the right-hand operand is an expression or a reference 9912 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 9913 ** will probably return [SQLITE_NOTFOUND]. 9914 ** 9915 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 9916 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 9917 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 9918 ** 9919 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 9920 ** and remains valid for the duration of the xBestIndex method call. 9921 ** ^When xBestIndex returns, the sqlite3_value object returned by 9922 ** sqlite3_vtab_rhs_value() is automatically deallocated. 9923 ** 9924 ** The "_rhs_" in the name of this routine is an abbreviation for 9925 ** "Right-Hand Side". 9926 */ 9927 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 9928 9929 /* 9930 ** CAPI3REF: Conflict resolution modes 9931 ** KEYWORDS: {conflict resolution mode} 9932 ** 9933 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 9934 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 9935 ** is for the SQL statement being evaluated. 9936 ** 9937 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 9938 ** return value from the [sqlite3_set_authorizer()] callback and that 9939 ** [SQLITE_ABORT] is also a [result code]. 9940 */ 9941 #define SQLITE_ROLLBACK 1 9942 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9943 #define SQLITE_FAIL 3 9944 /* #define SQLITE_ABORT 4 // Also an error code */ 9945 #define SQLITE_REPLACE 5 9946 9947 /* 9948 ** CAPI3REF: Prepared Statement Scan Status Opcodes 9949 ** KEYWORDS: {scanstatus options} 9950 ** 9951 ** The following constants can be used for the T parameter to the 9952 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9953 ** different metric for sqlite3_stmt_scanstatus() to return. 9954 ** 9955 ** When the value returned to V is a string, space to hold that string is 9956 ** managed by the prepared statement S and will be automatically freed when 9957 ** S is finalized. 9958 ** 9959 ** <dl> 9960 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9961 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9962 ** set to the total number of times that the X-th loop has run.</dd> 9963 ** 9964 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9965 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9966 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 9967 ** 9968 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9969 ** <dd>^The "double" variable pointed to by the V parameter will be set to the 9970 ** query planner's estimate for the average number of rows output from each 9971 ** iteration of the X-th loop. If the query planner's estimates was accurate, 9972 ** then this value will approximate the quotient NVISIT/NLOOP and the 9973 ** product of this value for all prior loops with the same SELECTID will 9974 ** be the NLOOP value for the current loop. 9975 ** 9976 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9977 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9978 ** to a zero-terminated UTF-8 string containing the name of the index or table 9979 ** used for the X-th loop. 9980 ** 9981 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9982 ** <dd>^The "const char *" variable pointed to by the V parameter will be set 9983 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9984 ** description for the X-th loop. 9985 ** 9986 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9987 ** <dd>^The "int" variable pointed to by the V parameter will be set to the 9988 ** "select-id" for the X-th loop. The select-id identifies which query or 9989 ** subquery the loop is part of. The main query has a select-id of zero. 9990 ** The select-id is the same value as is output in the first column 9991 ** of an [EXPLAIN QUERY PLAN] query. 9992 ** </dl> 9993 */ 9994 #define SQLITE_SCANSTAT_NLOOP 0 9995 #define SQLITE_SCANSTAT_NVISIT 1 9996 #define SQLITE_SCANSTAT_EST 2 9997 #define SQLITE_SCANSTAT_NAME 3 9998 #define SQLITE_SCANSTAT_EXPLAIN 4 9999 #define SQLITE_SCANSTAT_SELECTID 5 10000 10001 /* 10002 ** CAPI3REF: Prepared Statement Scan Status 10003 ** METHOD: sqlite3_stmt 10004 ** 10005 ** This interface returns information about the predicted and measured 10006 ** performance for pStmt. Advanced applications can use this 10007 ** interface to compare the predicted and the measured performance and 10008 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 10009 ** 10010 ** Since this interface is expected to be rarely used, it is only 10011 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 10012 ** compile-time option. 10013 ** 10014 ** The "iScanStatusOp" parameter determines which status information to return. 10015 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 10016 ** of this interface is undefined. 10017 ** ^The requested measurement is written into a variable pointed to by 10018 ** the "pOut" parameter. 10019 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 10020 ** Loops are numbered starting from zero. ^If idx is out of range - less than 10021 ** zero or greater than or equal to the total number of loops used to implement 10022 ** the statement - a non-zero value is returned and the variable that pOut 10023 ** points to is unchanged. 10024 ** 10025 ** ^Statistics might not be available for all loops in all statements. ^In cases 10026 ** where there exist loops with no available statistics, this function behaves 10027 ** as if the loop did not exist - it returns non-zero and leave the variable 10028 ** that pOut points to unchanged. 10029 ** 10030 ** See also: [sqlite3_stmt_scanstatus_reset()] 10031 */ 10032 SQLITE_API int sqlite3_stmt_scanstatus( 10033 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10034 int idx, /* Index of loop to report on */ 10035 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10036 void *pOut /* Result written here */ 10037 ); 10038 10039 /* 10040 ** CAPI3REF: Zero Scan-Status Counters 10041 ** METHOD: sqlite3_stmt 10042 ** 10043 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10044 ** 10045 ** This API is only available if the library is built with pre-processor 10046 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10047 */ 10048 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10049 10050 /* 10051 ** CAPI3REF: Flush caches to disk mid-transaction 10052 ** METHOD: sqlite3 10053 ** 10054 ** ^If a write-transaction is open on [database connection] D when the 10055 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 10056 ** pages in the pager-cache that are not currently in use are written out 10057 ** to disk. A dirty page may be in use if a database cursor created by an 10058 ** active SQL statement is reading from it, or if it is page 1 of a database 10059 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10060 ** interface flushes caches for all schemas - "main", "temp", and 10061 ** any [attached] databases. 10062 ** 10063 ** ^If this function needs to obtain extra database locks before dirty pages 10064 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 10065 ** immediately and there is a busy-handler callback configured, it is invoked 10066 ** in the usual manner. ^If the required lock still cannot be obtained, then 10067 ** the database is skipped and an attempt made to flush any dirty pages 10068 ** belonging to the next (if any) database. ^If any databases are skipped 10069 ** because locks cannot be obtained, but no other error occurs, this 10070 ** function returns SQLITE_BUSY. 10071 ** 10072 ** ^If any other error occurs while flushing dirty pages to disk (for 10073 ** example an IO error or out-of-memory condition), then processing is 10074 ** abandoned and an SQLite [error code] is returned to the caller immediately. 10075 ** 10076 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10077 ** 10078 ** ^This function does not set the database handle error code or message 10079 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10080 */ 10081 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10082 10083 /* 10084 ** CAPI3REF: The pre-update hook. 10085 ** METHOD: sqlite3 10086 ** 10087 ** ^These interfaces are only available if SQLite is compiled using the 10088 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10089 ** 10090 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10091 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10092 ** on a database table. 10093 ** ^At most one preupdate hook may be registered at a time on a single 10094 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10095 ** the previous setting. 10096 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10097 ** with a NULL pointer as the second parameter. 10098 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10099 ** the first parameter to callbacks. 10100 ** 10101 ** ^The preupdate hook only fires for changes to real database tables; the 10102 ** preupdate hook is not invoked for changes to [virtual tables] or to 10103 ** system tables like sqlite_sequence or sqlite_stat1. 10104 ** 10105 ** ^The second parameter to the preupdate callback is a pointer to 10106 ** the [database connection] that registered the preupdate hook. 10107 ** ^The third parameter to the preupdate callback is one of the constants 10108 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10109 ** kind of update operation that is about to occur. 10110 ** ^(The fourth parameter to the preupdate callback is the name of the 10111 ** database within the database connection that is being modified. This 10112 ** will be "main" for the main database or "temp" for TEMP tables or 10113 ** the name given after the AS keyword in the [ATTACH] statement for attached 10114 ** databases.)^ 10115 ** ^The fifth parameter to the preupdate callback is the name of the 10116 ** table that is being modified. 10117 ** 10118 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 10119 ** parameter passed to the preupdate callback is the initial [rowid] of the 10120 ** row being modified or deleted. For an INSERT operation on a rowid table, 10121 ** or any operation on a WITHOUT ROWID table, the value of the sixth 10122 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10123 ** seventh parameter is the final rowid value of the row being inserted 10124 ** or updated. The value of the seventh parameter passed to the callback 10125 ** function is not defined for operations on WITHOUT ROWID tables, or for 10126 ** DELETE operations on rowid tables. 10127 ** 10128 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10129 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10130 ** provide additional information about a preupdate event. These routines 10131 ** may only be called from within a preupdate callback. Invoking any of 10132 ** these routines from outside of a preupdate callback or with a 10133 ** [database connection] pointer that is different from the one supplied 10134 ** to the preupdate callback results in undefined and probably undesirable 10135 ** behavior. 10136 ** 10137 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10138 ** in the row that is being inserted, updated, or deleted. 10139 ** 10140 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10141 ** a [protected sqlite3_value] that contains the value of the Nth column of 10142 ** the table row before it is updated. The N parameter must be between 0 10143 ** and one less than the number of columns or the behavior will be 10144 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10145 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10146 ** behavior is undefined. The [sqlite3_value] that P points to 10147 ** will be destroyed when the preupdate callback returns. 10148 ** 10149 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10150 ** a [protected sqlite3_value] that contains the value of the Nth column of 10151 ** the table row after it is updated. The N parameter must be between 0 10152 ** and one less than the number of columns or the behavior will be 10153 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10154 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10155 ** behavior is undefined. The [sqlite3_value] that P points to 10156 ** will be destroyed when the preupdate callback returns. 10157 ** 10158 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10159 ** callback was invoked as a result of a direct insert, update, or delete 10160 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 10161 ** triggers; or 2 for changes resulting from triggers called by top-level 10162 ** triggers; and so forth. 10163 ** 10164 ** When the [sqlite3_blob_write()] API is used to update a blob column, 10165 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10166 ** in this case the new values are not available. In this case, when a 10167 ** callback made with op==SQLITE_DELETE is actuall a write using the 10168 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10169 ** the index of the column being written. In other cases, where the 10170 ** pre-update hook is being invoked for some other reason, including a 10171 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10172 ** 10173 ** See also: [sqlite3_update_hook()] 10174 */ 10175 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10176 SQLITE_API void *sqlite3_preupdate_hook( 10177 sqlite3 *db, 10178 void(*xPreUpdate)( 10179 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10180 sqlite3 *db, /* Database handle */ 10181 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10182 char const *zDb, /* Database name */ 10183 char const *zName, /* Table name */ 10184 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10185 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10186 ), 10187 void* 10188 ); 10189 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10190 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10191 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10192 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10193 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10194 #endif 10195 10196 /* 10197 ** CAPI3REF: Low-level system error code 10198 ** METHOD: sqlite3 10199 ** 10200 ** ^Attempt to return the underlying operating system error code or error 10201 ** number that caused the most recent I/O error or failure to open a file. 10202 ** The return value is OS-dependent. For example, on unix systems, after 10203 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10204 ** called to get back the underlying "errno" that caused the problem, such 10205 ** as ENOSPC, EAUTH, EISDIR, and so forth. 10206 */ 10207 SQLITE_API int sqlite3_system_errno(sqlite3*); 10208 10209 /* 10210 ** CAPI3REF: Database Snapshot 10211 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 10212 ** 10213 ** An instance of the snapshot object records the state of a [WAL mode] 10214 ** database for some specific point in history. 10215 ** 10216 ** In [WAL mode], multiple [database connections] that are open on the 10217 ** same database file can each be reading a different historical version 10218 ** of the database file. When a [database connection] begins a read 10219 ** transaction, that connection sees an unchanging copy of the database 10220 ** as it existed for the point in time when the transaction first started. 10221 ** Subsequent changes to the database from other connections are not seen 10222 ** by the reader until a new read transaction is started. 10223 ** 10224 ** The sqlite3_snapshot object records state information about an historical 10225 ** version of the database file so that it is possible to later open a new read 10226 ** transaction that sees that historical version of the database rather than 10227 ** the most recent version. 10228 */ 10229 typedef struct sqlite3_snapshot { 10230 unsigned char hidden[48]; 10231 } sqlite3_snapshot; 10232 10233 /* 10234 ** CAPI3REF: Record A Database Snapshot 10235 ** CONSTRUCTOR: sqlite3_snapshot 10236 ** 10237 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10238 ** new [sqlite3_snapshot] object that records the current state of 10239 ** schema S in database connection D. ^On success, the 10240 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10241 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10242 ** If there is not already a read-transaction open on schema S when 10243 ** this function is called, one is opened automatically. 10244 ** 10245 ** The following must be true for this function to succeed. If any of 10246 ** the following statements are false when sqlite3_snapshot_get() is 10247 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 10248 ** in this case. 10249 ** 10250 ** <ul> 10251 ** <li> The database handle must not be in [autocommit mode]. 10252 ** 10253 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 10254 ** 10255 ** <li> There must not be a write transaction open on schema S of database 10256 ** connection D. 10257 ** 10258 ** <li> One or more transactions must have been written to the current wal 10259 ** file since it was created on disk (by any connection). This means 10260 ** that a snapshot cannot be taken on a wal mode database with no wal 10261 ** file immediately after it is first opened. At least one transaction 10262 ** must be written to it first. 10263 ** </ul> 10264 ** 10265 ** This function may also return SQLITE_NOMEM. If it is called with the 10266 ** database handle in autocommit mode but fails for some other reason, 10267 ** whether or not a read transaction is opened on schema S is undefined. 10268 ** 10269 ** The [sqlite3_snapshot] object returned from a successful call to 10270 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10271 ** to avoid a memory leak. 10272 ** 10273 ** The [sqlite3_snapshot_get()] interface is only available when the 10274 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10275 */ 10276 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10277 sqlite3 *db, 10278 const char *zSchema, 10279 sqlite3_snapshot **ppSnapshot 10280 ); 10281 10282 /* 10283 ** CAPI3REF: Start a read transaction on an historical snapshot 10284 ** METHOD: sqlite3_snapshot 10285 ** 10286 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10287 ** transaction or upgrades an existing one for schema S of 10288 ** [database connection] D such that the read transaction refers to 10289 ** historical [snapshot] P, rather than the most recent change to the 10290 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10291 ** on success or an appropriate [error code] if it fails. 10292 ** 10293 ** ^In order to succeed, the database connection must not be in 10294 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10295 ** is already a read transaction open on schema S, then the database handle 10296 ** must have no active statements (SELECT statements that have been passed 10297 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10298 ** SQLITE_ERROR is returned if either of these conditions is violated, or 10299 ** if schema S does not exist, or if the snapshot object is invalid. 10300 ** 10301 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10302 ** snapshot has been overwritten by a [checkpoint]. In this case 10303 ** SQLITE_ERROR_SNAPSHOT is returned. 10304 ** 10305 ** If there is already a read transaction open when this function is 10306 ** invoked, then the same read transaction remains open (on the same 10307 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10308 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 10309 ** SQLITE_IOERR error code - is returned, then the final state of the 10310 ** read transaction is undefined. If SQLITE_OK is returned, then the 10311 ** read transaction is now open on database snapshot P. 10312 ** 10313 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10314 ** database connection D does not know that the database file for 10315 ** schema S is in [WAL mode]. A database connection might not know 10316 ** that the database file is in [WAL mode] if there has been no prior 10317 ** I/O on that database connection, or if the database entered [WAL mode] 10318 ** after the most recent I/O on the database connection.)^ 10319 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 10320 ** database connection in order to make it ready to use snapshots.) 10321 ** 10322 ** The [sqlite3_snapshot_open()] interface is only available when the 10323 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10324 */ 10325 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10326 sqlite3 *db, 10327 const char *zSchema, 10328 sqlite3_snapshot *pSnapshot 10329 ); 10330 10331 /* 10332 ** CAPI3REF: Destroy a snapshot 10333 ** DESTRUCTOR: sqlite3_snapshot 10334 ** 10335 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10336 ** The application must eventually free every [sqlite3_snapshot] object 10337 ** using this routine to avoid a memory leak. 10338 ** 10339 ** The [sqlite3_snapshot_free()] interface is only available when the 10340 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10341 */ 10342 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10343 10344 /* 10345 ** CAPI3REF: Compare the ages of two snapshot handles. 10346 ** METHOD: sqlite3_snapshot 10347 ** 10348 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10349 ** of two valid snapshot handles. 10350 ** 10351 ** If the two snapshot handles are not associated with the same database 10352 ** file, the result of the comparison is undefined. 10353 ** 10354 ** Additionally, the result of the comparison is only valid if both of the 10355 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10356 ** last time the wal file was deleted. The wal file is deleted when the 10357 ** database is changed back to rollback mode or when the number of database 10358 ** clients drops to zero. If either snapshot handle was obtained before the 10359 ** wal file was last deleted, the value returned by this function 10360 ** is undefined. 10361 ** 10362 ** Otherwise, this API returns a negative value if P1 refers to an older 10363 ** snapshot than P2, zero if the two handles refer to the same database 10364 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 10365 ** 10366 ** This interface is only available if SQLite is compiled with the 10367 ** [SQLITE_ENABLE_SNAPSHOT] option. 10368 */ 10369 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10370 sqlite3_snapshot *p1, 10371 sqlite3_snapshot *p2 10372 ); 10373 10374 /* 10375 ** CAPI3REF: Recover snapshots from a wal file 10376 ** METHOD: sqlite3_snapshot 10377 ** 10378 ** If a [WAL file] remains on disk after all database connections close 10379 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10380 ** or because the last process to have the database opened exited without 10381 ** calling [sqlite3_close()]) and a new connection is subsequently opened 10382 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10383 ** will only be able to open the last transaction added to the WAL file 10384 ** even though the WAL file contains other valid transactions. 10385 ** 10386 ** This function attempts to scan the WAL file associated with database zDb 10387 ** of database handle db and make all valid snapshots available to 10388 ** sqlite3_snapshot_open(). It is an error if there is already a read 10389 ** transaction open on the database, or if the database is not a WAL mode 10390 ** database. 10391 ** 10392 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10393 ** 10394 ** This interface is only available if SQLite is compiled with the 10395 ** [SQLITE_ENABLE_SNAPSHOT] option. 10396 */ 10397 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10398 10399 /* 10400 ** CAPI3REF: Serialize a database 10401 ** 10402 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10403 ** that is a serialization of the S database on [database connection] D. 10404 ** If P is not a NULL pointer, then the size of the database in bytes 10405 ** is written into *P. 10406 ** 10407 ** For an ordinary on-disk database file, the serialization is just a 10408 ** copy of the disk file. For an in-memory database or a "TEMP" database, 10409 ** the serialization is the same sequence of bytes which would be written 10410 ** to disk if that database where backed up to disk. 10411 ** 10412 ** The usual case is that sqlite3_serialize() copies the serialization of 10413 ** the database into memory obtained from [sqlite3_malloc64()] and returns 10414 ** a pointer to that memory. The caller is responsible for freeing the 10415 ** returned value to avoid a memory leak. However, if the F argument 10416 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10417 ** are made, and the sqlite3_serialize() function will return a pointer 10418 ** to the contiguous memory representation of the database that SQLite 10419 ** is currently using for that database, or NULL if the no such contiguous 10420 ** memory representation of the database exists. A contiguous memory 10421 ** representation of the database will usually only exist if there has 10422 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10423 ** values of D and S. 10424 ** The size of the database is written into *P even if the 10425 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10426 ** of the database exists. 10427 ** 10428 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10429 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10430 ** allocation error occurs. 10431 ** 10432 ** This interface is omitted if SQLite is compiled with the 10433 ** [SQLITE_OMIT_DESERIALIZE] option. 10434 */ 10435 SQLITE_API unsigned char *sqlite3_serialize( 10436 sqlite3 *db, /* The database connection */ 10437 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10438 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10439 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10440 ); 10441 10442 /* 10443 ** CAPI3REF: Flags for sqlite3_serialize 10444 ** 10445 ** Zero or more of the following constants can be OR-ed together for 10446 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 10447 ** 10448 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10449 ** a pointer to contiguous in-memory database that it is currently using, 10450 ** without making a copy of the database. If SQLite is not currently using 10451 ** a contiguous in-memory database, then this option causes 10452 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10453 ** using a contiguous in-memory database if it has been initialized by a 10454 ** prior call to [sqlite3_deserialize()]. 10455 */ 10456 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10457 10458 /* 10459 ** CAPI3REF: Deserialize a database 10460 ** 10461 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10462 ** [database connection] D to disconnect from database S and then 10463 ** reopen S as an in-memory database based on the serialization contained 10464 ** in P. The serialized database P is N bytes in size. M is the size of 10465 ** the buffer P, which might be larger than N. If M is larger than N, and 10466 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10467 ** permitted to add content to the in-memory database as long as the total 10468 ** size does not exceed M bytes. 10469 ** 10470 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10471 ** invoke sqlite3_free() on the serialization buffer when the database 10472 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10473 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 10474 ** if writes on the database cause it to grow larger than M bytes. 10475 ** 10476 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10477 ** database is currently in a read transaction or is involved in a backup 10478 ** operation. 10479 ** 10480 ** It is not possible to deserialized into the TEMP database. If the 10481 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10482 ** function returns SQLITE_ERROR. 10483 ** 10484 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10485 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10486 ** [sqlite3_free()] is invoked on argument P prior to returning. 10487 ** 10488 ** This interface is omitted if SQLite is compiled with the 10489 ** [SQLITE_OMIT_DESERIALIZE] option. 10490 */ 10491 SQLITE_API int sqlite3_deserialize( 10492 sqlite3 *db, /* The database connection */ 10493 const char *zSchema, /* Which DB to reopen with the deserialization */ 10494 unsigned char *pData, /* The serialized database content */ 10495 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10496 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10497 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10498 ); 10499 10500 /* 10501 ** CAPI3REF: Flags for sqlite3_deserialize() 10502 ** 10503 ** The following are allowed values for 6th argument (the F argument) to 10504 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10505 ** 10506 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10507 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10508 ** and that SQLite should take ownership of this memory and automatically 10509 ** free it when it has finished using it. Without this flag, the caller 10510 ** is responsible for freeing any dynamically allocated memory. 10511 ** 10512 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10513 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 10514 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10515 ** Without this flag, the deserialized database cannot increase in size beyond 10516 ** the number of bytes specified by the M parameter. 10517 ** 10518 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10519 ** should be treated as read-only. 10520 */ 10521 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10522 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10523 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10524 10525 /* 10526 ** Undo the hack that converts floating point types to integer for 10527 ** builds on processors without floating point support. 10528 */ 10529 #ifdef SQLITE_OMIT_FLOATING_POINT 10530 # undef double 10531 #endif 10532 10533 #ifdef __cplusplus 10534 } /* End of the 'extern "C"' block */ 10535 #endif 10536 #endif /* SQLITE3_H */ 10537 10538 /******** Begin file sqlite3rtree.h *********/ 10539 /* 10540 ** 2010 August 30 10541 ** 10542 ** The author disclaims copyright to this source code. In place of 10543 ** a legal notice, here is a blessing: 10544 ** 10545 ** May you do good and not evil. 10546 ** May you find forgiveness for yourself and forgive others. 10547 ** May you share freely, never taking more than you give. 10548 ** 10549 ************************************************************************* 10550 */ 10551 10552 #ifndef _SQLITE3RTREE_H_ 10553 #define _SQLITE3RTREE_H_ 10554 10555 10556 #ifdef __cplusplus 10557 extern "C" { 10558 #endif 10559 10560 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10561 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10562 10563 /* The double-precision datatype used by RTree depends on the 10564 ** SQLITE_RTREE_INT_ONLY compile-time option. 10565 */ 10566 #ifdef SQLITE_RTREE_INT_ONLY 10567 typedef sqlite3_int64 sqlite3_rtree_dbl; 10568 #else 10569 typedef double sqlite3_rtree_dbl; 10570 #endif 10571 10572 /* 10573 ** Register a geometry callback named zGeom that can be used as part of an 10574 ** R-Tree geometry query as follows: 10575 ** 10576 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10577 */ 10578 SQLITE_API int sqlite3_rtree_geometry_callback( 10579 sqlite3 *db, 10580 const char *zGeom, 10581 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10582 void *pContext 10583 ); 10584 10585 10586 /* 10587 ** A pointer to a structure of the following type is passed as the first 10588 ** argument to callbacks registered using rtree_geometry_callback(). 10589 */ 10590 struct sqlite3_rtree_geometry { 10591 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10592 int nParam; /* Size of array aParam[] */ 10593 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10594 void *pUser; /* Callback implementation user data */ 10595 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10596 }; 10597 10598 /* 10599 ** Register a 2nd-generation geometry callback named zScore that can be 10600 ** used as part of an R-Tree geometry query as follows: 10601 ** 10602 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10603 */ 10604 SQLITE_API int sqlite3_rtree_query_callback( 10605 sqlite3 *db, 10606 const char *zQueryFunc, 10607 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10608 void *pContext, 10609 void (*xDestructor)(void*) 10610 ); 10611 10612 10613 /* 10614 ** A pointer to a structure of the following type is passed as the 10615 ** argument to scored geometry callback registered using 10616 ** sqlite3_rtree_query_callback(). 10617 ** 10618 ** Note that the first 5 fields of this structure are identical to 10619 ** sqlite3_rtree_geometry. This structure is a subclass of 10620 ** sqlite3_rtree_geometry. 10621 */ 10622 struct sqlite3_rtree_query_info { 10623 void *pContext; /* pContext from when function registered */ 10624 int nParam; /* Number of function parameters */ 10625 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10626 void *pUser; /* callback can use this, if desired */ 10627 void (*xDelUser)(void*); /* function to free pUser */ 10628 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10629 unsigned int *anQueue; /* Number of pending entries in the queue */ 10630 int nCoord; /* Number of coordinates */ 10631 int iLevel; /* Level of current node or entry */ 10632 int mxLevel; /* The largest iLevel value in the tree */ 10633 sqlite3_int64 iRowid; /* Rowid for current entry */ 10634 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10635 int eParentWithin; /* Visibility of parent node */ 10636 int eWithin; /* OUT: Visibility */ 10637 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10638 /* The following fields are only available in 3.8.11 and later */ 10639 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10640 }; 10641 10642 /* 10643 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10644 */ 10645 #define NOT_WITHIN 0 /* Object completely outside of query region */ 10646 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10647 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 10648 10649 10650 #ifdef __cplusplus 10651 } /* end of the 'extern "C"' block */ 10652 #endif 10653 10654 #endif /* ifndef _SQLITE3RTREE_H_ */ 10655 10656 /******** End of sqlite3rtree.h *********/ 10657 /******** Begin file sqlite3session.h *********/ 10658 10659 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10660 #define __SQLITESESSION_H_ 1 10661 10662 /* 10663 ** Make sure we can call this stuff from C++. 10664 */ 10665 #ifdef __cplusplus 10666 extern "C" { 10667 #endif 10668 10669 10670 /* 10671 ** CAPI3REF: Session Object Handle 10672 ** 10673 ** An instance of this object is a [session] that can be used to 10674 ** record changes to a database. 10675 */ 10676 typedef struct sqlite3_session sqlite3_session; 10677 10678 /* 10679 ** CAPI3REF: Changeset Iterator Handle 10680 ** 10681 ** An instance of this object acts as a cursor for iterating 10682 ** over the elements of a [changeset] or [patchset]. 10683 */ 10684 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10685 10686 /* 10687 ** CAPI3REF: Create A New Session Object 10688 ** CONSTRUCTOR: sqlite3_session 10689 ** 10690 ** Create a new session object attached to database handle db. If successful, 10691 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 10692 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10693 ** error code (e.g. SQLITE_NOMEM) is returned. 10694 ** 10695 ** It is possible to create multiple session objects attached to a single 10696 ** database handle. 10697 ** 10698 ** Session objects created using this function should be deleted using the 10699 ** [sqlite3session_delete()] function before the database handle that they 10700 ** are attached to is itself closed. If the database handle is closed before 10701 ** the session object is deleted, then the results of calling any session 10702 ** module function, including [sqlite3session_delete()] on the session object 10703 ** are undefined. 10704 ** 10705 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10706 ** is not possible for an application to register a pre-update hook on a 10707 ** database handle that has one or more session objects attached. Nor is 10708 ** it possible to create a session object attached to a database handle for 10709 ** which a pre-update hook is already defined. The results of attempting 10710 ** either of these things are undefined. 10711 ** 10712 ** The session object will be used to create changesets for tables in 10713 ** database zDb, where zDb is either "main", or "temp", or the name of an 10714 ** attached database. It is not an error if database zDb is not attached 10715 ** to the database when the session object is created. 10716 */ 10717 SQLITE_API int sqlite3session_create( 10718 sqlite3 *db, /* Database handle */ 10719 const char *zDb, /* Name of db (e.g. "main") */ 10720 sqlite3_session **ppSession /* OUT: New session object */ 10721 ); 10722 10723 /* 10724 ** CAPI3REF: Delete A Session Object 10725 ** DESTRUCTOR: sqlite3_session 10726 ** 10727 ** Delete a session object previously allocated using 10728 ** [sqlite3session_create()]. Once a session object has been deleted, the 10729 ** results of attempting to use pSession with any other session module 10730 ** function are undefined. 10731 ** 10732 ** Session objects must be deleted before the database handle to which they 10733 ** are attached is closed. Refer to the documentation for 10734 ** [sqlite3session_create()] for details. 10735 */ 10736 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10737 10738 /* 10739 ** CAPIREF: Conigure a Session Object 10740 ** METHOD: sqlite3_session 10741 ** 10742 ** This method is used to configure a session object after it has been 10743 ** created. At present the only valid value for the second parameter is 10744 ** [SQLITE_SESSION_OBJCONFIG_SIZE]. 10745 ** 10746 ** Arguments for sqlite3session_object_config() 10747 ** 10748 ** The following values may passed as the the 4th parameter to 10749 ** sqlite3session_object_config(). 10750 ** 10751 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10752 ** This option is used to set, clear or query the flag that enables 10753 ** the [sqlite3session_changeset_size()] API. Because it imposes some 10754 ** computational overhead, this API is disabled by default. Argument 10755 ** pArg must point to a value of type (int). If the value is initially 10756 ** 0, then the sqlite3session_changeset_size() API is disabled. If it 10757 ** is greater than 0, then the same API is enabled. Or, if the initial 10758 ** value is less than zero, no change is made. In all cases the (int) 10759 ** variable is set to 1 if the sqlite3session_changeset_size() API is 10760 ** enabled following the current call, or 0 otherwise. 10761 ** 10762 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10763 ** the first table has been attached to the session object. 10764 */ 10765 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10766 10767 /* 10768 */ 10769 #define SQLITE_SESSION_OBJCONFIG_SIZE 1 10770 10771 /* 10772 ** CAPI3REF: Enable Or Disable A Session Object 10773 ** METHOD: sqlite3_session 10774 ** 10775 ** Enable or disable the recording of changes by a session object. When 10776 ** enabled, a session object records changes made to the database. When 10777 ** disabled - it does not. A newly created session object is enabled. 10778 ** Refer to the documentation for [sqlite3session_changeset()] for further 10779 ** details regarding how enabling and disabling a session object affects 10780 ** the eventual changesets. 10781 ** 10782 ** Passing zero to this function disables the session. Passing a value 10783 ** greater than zero enables it. Passing a value less than zero is a 10784 ** no-op, and may be used to query the current state of the session. 10785 ** 10786 ** The return value indicates the final state of the session object: 0 if 10787 ** the session is disabled, or 1 if it is enabled. 10788 */ 10789 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10790 10791 /* 10792 ** CAPI3REF: Set Or Clear the Indirect Change Flag 10793 ** METHOD: sqlite3_session 10794 ** 10795 ** Each change recorded by a session object is marked as either direct or 10796 ** indirect. A change is marked as indirect if either: 10797 ** 10798 ** <ul> 10799 ** <li> The session object "indirect" flag is set when the change is 10800 ** made, or 10801 ** <li> The change is made by an SQL trigger or foreign key action 10802 ** instead of directly as a result of a users SQL statement. 10803 ** </ul> 10804 ** 10805 ** If a single row is affected by more than one operation within a session, 10806 ** then the change is considered indirect if all operations meet the criteria 10807 ** for an indirect change above, or direct otherwise. 10808 ** 10809 ** This function is used to set, clear or query the session object indirect 10810 ** flag. If the second argument passed to this function is zero, then the 10811 ** indirect flag is cleared. If it is greater than zero, the indirect flag 10812 ** is set. Passing a value less than zero does not modify the current value 10813 ** of the indirect flag, and may be used to query the current state of the 10814 ** indirect flag for the specified session object. 10815 ** 10816 ** The return value indicates the final state of the indirect flag: 0 if 10817 ** it is clear, or 1 if it is set. 10818 */ 10819 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10820 10821 /* 10822 ** CAPI3REF: Attach A Table To A Session Object 10823 ** METHOD: sqlite3_session 10824 ** 10825 ** If argument zTab is not NULL, then it is the name of a table to attach 10826 ** to the session object passed as the first argument. All subsequent changes 10827 ** made to the table while the session object is enabled will be recorded. See 10828 ** documentation for [sqlite3session_changeset()] for further details. 10829 ** 10830 ** Or, if argument zTab is NULL, then changes are recorded for all tables 10831 ** in the database. If additional tables are added to the database (by 10832 ** executing "CREATE TABLE" statements) after this call is made, changes for 10833 ** the new tables are also recorded. 10834 ** 10835 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10836 ** defined as part of their CREATE TABLE statement. It does not matter if the 10837 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10838 ** KEY may consist of a single column, or may be a composite key. 10839 ** 10840 ** It is not an error if the named table does not exist in the database. Nor 10841 ** is it an error if the named table does not have a PRIMARY KEY. However, 10842 ** no changes will be recorded in either of these scenarios. 10843 ** 10844 ** Changes are not recorded for individual rows that have NULL values stored 10845 ** in one or more of their PRIMARY KEY columns. 10846 ** 10847 ** SQLITE_OK is returned if the call completes without error. Or, if an error 10848 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10849 ** 10850 ** <h3>Special sqlite_stat1 Handling</h3> 10851 ** 10852 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10853 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10854 ** <pre> 10855 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10856 ** </pre> 10857 ** 10858 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10859 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10860 ** are recorded for rows for which (idx IS NULL) is true. However, for such 10861 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 10862 ** patchset instead of a NULL value. This allows such changesets to be 10863 ** manipulated by legacy implementations of sqlite3changeset_invert(), 10864 ** concat() and similar. 10865 ** 10866 ** The sqlite3changeset_apply() function automatically converts the 10867 ** zero-length blob back to a NULL value when updating the sqlite_stat1 10868 ** table. However, if the application calls sqlite3changeset_new(), 10869 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10870 ** iterator directly (including on a changeset iterator passed to a 10871 ** conflict-handler callback) then the X'' value is returned. The application 10872 ** must translate X'' to NULL itself if required. 10873 ** 10874 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10875 ** changes made to the sqlite_stat1 table. Legacy versions of the 10876 ** sqlite3changeset_apply() function silently ignore any modifications to the 10877 ** sqlite_stat1 table that are part of a changeset or patchset. 10878 */ 10879 SQLITE_API int sqlite3session_attach( 10880 sqlite3_session *pSession, /* Session object */ 10881 const char *zTab /* Table name */ 10882 ); 10883 10884 /* 10885 ** CAPI3REF: Set a table filter on a Session Object. 10886 ** METHOD: sqlite3_session 10887 ** 10888 ** The second argument (xFilter) is the "filter callback". For changes to rows 10889 ** in tables that are not attached to the Session object, the filter is called 10890 ** to determine whether changes to the table's rows should be tracked or not. 10891 ** If xFilter returns 0, changes are not tracked. Note that once a table is 10892 ** attached, xFilter will not be called again. 10893 */ 10894 SQLITE_API void sqlite3session_table_filter( 10895 sqlite3_session *pSession, /* Session object */ 10896 int(*xFilter)( 10897 void *pCtx, /* Copy of third arg to _filter_table() */ 10898 const char *zTab /* Table name */ 10899 ), 10900 void *pCtx /* First argument passed to xFilter */ 10901 ); 10902 10903 /* 10904 ** CAPI3REF: Generate A Changeset From A Session Object 10905 ** METHOD: sqlite3_session 10906 ** 10907 ** Obtain a changeset containing changes to the tables attached to the 10908 ** session object passed as the first argument. If successful, 10909 ** set *ppChangeset to point to a buffer containing the changeset 10910 ** and *pnChangeset to the size of the changeset in bytes before returning 10911 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10912 ** zero and return an SQLite error code. 10913 ** 10914 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10915 ** each representing a change to a single row of an attached table. An INSERT 10916 ** change contains the values of each field of a new database row. A DELETE 10917 ** contains the original values of each field of a deleted database row. An 10918 ** UPDATE change contains the original values of each field of an updated 10919 ** database row along with the updated values for each updated non-primary-key 10920 ** column. It is not possible for an UPDATE change to represent a change that 10921 ** modifies the values of primary key columns. If such a change is made, it 10922 ** is represented in a changeset as a DELETE followed by an INSERT. 10923 ** 10924 ** Changes are not recorded for rows that have NULL values stored in one or 10925 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10926 ** no corresponding change is present in the changesets returned by this 10927 ** function. If an existing row with one or more NULL values stored in 10928 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10929 ** only an INSERT is appears in the changeset. Similarly, if an existing row 10930 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 10931 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10932 ** DELETE change only. 10933 ** 10934 ** The contents of a changeset may be traversed using an iterator created 10935 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 10936 ** a database with a compatible schema using the [sqlite3changeset_apply()] 10937 ** API. 10938 ** 10939 ** Within a changeset generated by this function, all changes related to a 10940 ** single table are grouped together. In other words, when iterating through 10941 ** a changeset or when applying a changeset to a database, all changes related 10942 ** to a single table are processed before moving on to the next table. Tables 10943 ** are sorted in the same order in which they were attached (or auto-attached) 10944 ** to the sqlite3_session object. The order in which the changes related to 10945 ** a single table are stored is undefined. 10946 ** 10947 ** Following a successful call to this function, it is the responsibility of 10948 ** the caller to eventually free the buffer that *ppChangeset points to using 10949 ** [sqlite3_free()]. 10950 ** 10951 ** <h3>Changeset Generation</h3> 10952 ** 10953 ** Once a table has been attached to a session object, the session object 10954 ** records the primary key values of all new rows inserted into the table. 10955 ** It also records the original primary key and other column values of any 10956 ** deleted or updated rows. For each unique primary key value, data is only 10957 ** recorded once - the first time a row with said primary key is inserted, 10958 ** updated or deleted in the lifetime of the session. 10959 ** 10960 ** There is one exception to the previous paragraph: when a row is inserted, 10961 ** updated or deleted, if one or more of its primary key columns contain a 10962 ** NULL value, no record of the change is made. 10963 ** 10964 ** The session object therefore accumulates two types of records - those 10965 ** that consist of primary key values only (created when the user inserts 10966 ** a new record) and those that consist of the primary key values and the 10967 ** original values of other table columns (created when the users deletes 10968 ** or updates a record). 10969 ** 10970 ** When this function is called, the requested changeset is created using 10971 ** both the accumulated records and the current contents of the database 10972 ** file. Specifically: 10973 ** 10974 ** <ul> 10975 ** <li> For each record generated by an insert, the database is queried 10976 ** for a row with a matching primary key. If one is found, an INSERT 10977 ** change is added to the changeset. If no such row is found, no change 10978 ** is added to the changeset. 10979 ** 10980 ** <li> For each record generated by an update or delete, the database is 10981 ** queried for a row with a matching primary key. If such a row is 10982 ** found and one or more of the non-primary key fields have been 10983 ** modified from their original values, an UPDATE change is added to 10984 ** the changeset. Or, if no such row is found in the table, a DELETE 10985 ** change is added to the changeset. If there is a row with a matching 10986 ** primary key in the database, but all fields contain their original 10987 ** values, no change is added to the changeset. 10988 ** </ul> 10989 ** 10990 ** This means, amongst other things, that if a row is inserted and then later 10991 ** deleted while a session object is active, neither the insert nor the delete 10992 ** will be present in the changeset. Or if a row is deleted and then later a 10993 ** row with the same primary key values inserted while a session object is 10994 ** active, the resulting changeset will contain an UPDATE change instead of 10995 ** a DELETE and an INSERT. 10996 ** 10997 ** When a session object is disabled (see the [sqlite3session_enable()] API), 10998 ** it does not accumulate records when rows are inserted, updated or deleted. 10999 ** This may appear to have some counter-intuitive effects if a single row 11000 ** is written to more than once during a session. For example, if a row 11001 ** is inserted while a session object is enabled, then later deleted while 11002 ** the same session object is disabled, no INSERT record will appear in the 11003 ** changeset, even though the delete took place while the session was disabled. 11004 ** Or, if one field of a row is updated while a session is disabled, and 11005 ** another field of the same row is updated while the session is enabled, the 11006 ** resulting changeset will contain an UPDATE change that updates both fields. 11007 */ 11008 SQLITE_API int sqlite3session_changeset( 11009 sqlite3_session *pSession, /* Session object */ 11010 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 11011 void **ppChangeset /* OUT: Buffer containing changeset */ 11012 ); 11013 11014 /* 11015 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 11016 ** METHOD: sqlite3_session 11017 ** 11018 ** By default, this function always returns 0. For it to return 11019 ** a useful result, the sqlite3_session object must have been configured 11020 ** to enable this API using sqlite3session_object_config() with the 11021 ** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11022 ** 11023 ** When enabled, this function returns an upper limit, in bytes, for the size 11024 ** of the changeset that might be produced if sqlite3session_changeset() were 11025 ** called. The final changeset size might be equal to or smaller than the 11026 ** size in bytes returned by this function. 11027 */ 11028 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11029 11030 /* 11031 ** CAPI3REF: Load The Difference Between Tables Into A Session 11032 ** METHOD: sqlite3_session 11033 ** 11034 ** If it is not already attached to the session object passed as the first 11035 ** argument, this function attaches table zTbl in the same manner as the 11036 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11037 ** does not have a primary key, this function is a no-op (but does not return 11038 ** an error). 11039 ** 11040 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11041 ** attached to the same database handle as the session object that contains 11042 ** a table compatible with the table attached to the session by this function. 11043 ** A table is considered compatible if it: 11044 ** 11045 ** <ul> 11046 ** <li> Has the same name, 11047 ** <li> Has the same set of columns declared in the same order, and 11048 ** <li> Has the same PRIMARY KEY definition. 11049 ** </ul> 11050 ** 11051 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11052 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 11053 ** but no changes are added to the session object. As with other session 11054 ** APIs, tables without PRIMARY KEYs are simply ignored. 11055 ** 11056 ** This function adds a set of changes to the session object that could be 11057 ** used to update the table in database zFrom (call this the "from-table") 11058 ** so that its content is the same as the table attached to the session 11059 ** object (call this the "to-table"). Specifically: 11060 ** 11061 ** <ul> 11062 ** <li> For each row (primary key) that exists in the to-table but not in 11063 ** the from-table, an INSERT record is added to the session object. 11064 ** 11065 ** <li> For each row (primary key) that exists in the to-table but not in 11066 ** the from-table, a DELETE record is added to the session object. 11067 ** 11068 ** <li> For each row (primary key) that exists in both tables, but features 11069 ** different non-PK values in each, an UPDATE record is added to the 11070 ** session. 11071 ** </ul> 11072 ** 11073 ** To clarify, if this function is called and then a changeset constructed 11074 ** using [sqlite3session_changeset()], then after applying that changeset to 11075 ** database zFrom the contents of the two compatible tables would be 11076 ** identical. 11077 ** 11078 ** It an error if database zFrom does not exist or does not contain the 11079 ** required compatible table. 11080 ** 11081 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11082 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11083 ** may be set to point to a buffer containing an English language error 11084 ** message. It is the responsibility of the caller to free this buffer using 11085 ** sqlite3_free(). 11086 */ 11087 SQLITE_API int sqlite3session_diff( 11088 sqlite3_session *pSession, 11089 const char *zFromDb, 11090 const char *zTbl, 11091 char **pzErrMsg 11092 ); 11093 11094 11095 /* 11096 ** CAPI3REF: Generate A Patchset From A Session Object 11097 ** METHOD: sqlite3_session 11098 ** 11099 ** The differences between a patchset and a changeset are that: 11100 ** 11101 ** <ul> 11102 ** <li> DELETE records consist of the primary key fields only. The 11103 ** original values of other fields are omitted. 11104 ** <li> The original values of any modified fields are omitted from 11105 ** UPDATE records. 11106 ** </ul> 11107 ** 11108 ** A patchset blob may be used with up to date versions of all 11109 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11110 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11111 ** attempting to use a patchset blob with old versions of the 11112 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11113 ** 11114 ** Because the non-primary key "old.*" fields are omitted, no 11115 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11116 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 11117 ** in the same way as for changesets. 11118 ** 11119 ** Changes within a patchset are ordered in the same way as for changesets 11120 ** generated by the sqlite3session_changeset() function (i.e. all changes for 11121 ** a single table are grouped together, tables appear in the order in which 11122 ** they were attached to the session object). 11123 */ 11124 SQLITE_API int sqlite3session_patchset( 11125 sqlite3_session *pSession, /* Session object */ 11126 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11127 void **ppPatchset /* OUT: Buffer containing patchset */ 11128 ); 11129 11130 /* 11131 ** CAPI3REF: Test if a changeset has recorded any changes. 11132 ** 11133 ** Return non-zero if no changes to attached tables have been recorded by 11134 ** the session object passed as the first argument. Otherwise, if one or 11135 ** more changes have been recorded, return zero. 11136 ** 11137 ** Even if this function returns zero, it is possible that calling 11138 ** [sqlite3session_changeset()] on the session handle may still return a 11139 ** changeset that contains no changes. This can happen when a row in 11140 ** an attached table is modified and then later on the original values 11141 ** are restored. However, if this function returns non-zero, then it is 11142 ** guaranteed that a call to sqlite3session_changeset() will return a 11143 ** changeset containing zero changes. 11144 */ 11145 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11146 11147 /* 11148 ** CAPI3REF: Query for the amount of heap memory used by a session object. 11149 ** 11150 ** This API returns the total amount of heap memory in bytes currently 11151 ** used by the session object passed as the only argument. 11152 */ 11153 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11154 11155 /* 11156 ** CAPI3REF: Create An Iterator To Traverse A Changeset 11157 ** CONSTRUCTOR: sqlite3_changeset_iter 11158 ** 11159 ** Create an iterator used to iterate through the contents of a changeset. 11160 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11161 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11162 ** SQLite error code is returned. 11163 ** 11164 ** The following functions can be used to advance and query a changeset 11165 ** iterator created by this function: 11166 ** 11167 ** <ul> 11168 ** <li> [sqlite3changeset_next()] 11169 ** <li> [sqlite3changeset_op()] 11170 ** <li> [sqlite3changeset_new()] 11171 ** <li> [sqlite3changeset_old()] 11172 ** </ul> 11173 ** 11174 ** It is the responsibility of the caller to eventually destroy the iterator 11175 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11176 ** changeset (pChangeset) must remain valid until after the iterator is 11177 ** destroyed. 11178 ** 11179 ** Assuming the changeset blob was created by one of the 11180 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11181 ** [sqlite3changeset_invert()] functions, all changes within the changeset 11182 ** that apply to a single table are grouped together. This means that when 11183 ** an application iterates through a changeset using an iterator created by 11184 ** this function, all changes that relate to a single table are visited 11185 ** consecutively. There is no chance that the iterator will visit a change 11186 ** the applies to table X, then one for table Y, and then later on visit 11187 ** another change for table X. 11188 ** 11189 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11190 ** may be modified by passing a combination of 11191 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11192 ** 11193 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11194 ** and therefore subject to change. 11195 */ 11196 SQLITE_API int sqlite3changeset_start( 11197 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11198 int nChangeset, /* Size of changeset blob in bytes */ 11199 void *pChangeset /* Pointer to blob containing changeset */ 11200 ); 11201 SQLITE_API int sqlite3changeset_start_v2( 11202 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11203 int nChangeset, /* Size of changeset blob in bytes */ 11204 void *pChangeset, /* Pointer to blob containing changeset */ 11205 int flags /* SESSION_CHANGESETSTART_* flags */ 11206 ); 11207 11208 /* 11209 ** CAPI3REF: Flags for sqlite3changeset_start_v2 11210 ** 11211 ** The following flags may passed via the 4th parameter to 11212 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11213 ** 11214 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11215 ** Invert the changeset while iterating through it. This is equivalent to 11216 ** inverting a changeset using sqlite3changeset_invert() before applying it. 11217 ** It is an error to specify this flag with a patchset. 11218 */ 11219 #define SQLITE_CHANGESETSTART_INVERT 0x0002 11220 11221 11222 /* 11223 ** CAPI3REF: Advance A Changeset Iterator 11224 ** METHOD: sqlite3_changeset_iter 11225 ** 11226 ** This function may only be used with iterators created by the function 11227 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 11228 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11229 ** is returned and the call has no effect. 11230 ** 11231 ** Immediately after an iterator is created by sqlite3changeset_start(), it 11232 ** does not point to any change in the changeset. Assuming the changeset 11233 ** is not empty, the first call to this function advances the iterator to 11234 ** point to the first change in the changeset. Each subsequent call advances 11235 ** the iterator to point to the next change in the changeset (if any). If 11236 ** no error occurs and the iterator points to a valid change after a call 11237 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11238 ** Otherwise, if all changes in the changeset have already been visited, 11239 ** SQLITE_DONE is returned. 11240 ** 11241 ** If an error occurs, an SQLite error code is returned. Possible error 11242 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11243 ** SQLITE_NOMEM. 11244 */ 11245 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11246 11247 /* 11248 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11249 ** METHOD: sqlite3_changeset_iter 11250 ** 11251 ** The pIter argument passed to this function may either be an iterator 11252 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11253 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11254 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11255 ** is not the case, this function returns [SQLITE_MISUSE]. 11256 ** 11257 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11258 ** outputs are set through these pointers: 11259 ** 11260 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11261 ** depending on the type of change that the iterator currently points to; 11262 ** 11263 ** *pnCol is set to the number of columns in the table affected by the change; and 11264 ** 11265 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11266 ** the name of the table affected by the current change. The buffer remains 11267 ** valid until either sqlite3changeset_next() is called on the iterator 11268 ** or until the conflict-handler function returns. 11269 ** 11270 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11271 ** is an indirect change, or false (0) otherwise. See the documentation for 11272 ** [sqlite3session_indirect()] for a description of direct and indirect 11273 ** changes. 11274 ** 11275 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11276 ** SQLite error code is returned. The values of the output variables may not 11277 ** be trusted in this case. 11278 */ 11279 SQLITE_API int sqlite3changeset_op( 11280 sqlite3_changeset_iter *pIter, /* Iterator object */ 11281 const char **pzTab, /* OUT: Pointer to table name */ 11282 int *pnCol, /* OUT: Number of columns in table */ 11283 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11284 int *pbIndirect /* OUT: True for an 'indirect' change */ 11285 ); 11286 11287 /* 11288 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 11289 ** METHOD: sqlite3_changeset_iter 11290 ** 11291 ** For each modified table, a changeset includes the following: 11292 ** 11293 ** <ul> 11294 ** <li> The number of columns in the table, and 11295 ** <li> Which of those columns make up the tables PRIMARY KEY. 11296 ** </ul> 11297 ** 11298 ** This function is used to find which columns comprise the PRIMARY KEY of 11299 ** the table modified by the change that iterator pIter currently points to. 11300 ** If successful, *pabPK is set to point to an array of nCol entries, where 11301 ** nCol is the number of columns in the table. Elements of *pabPK are set to 11302 ** 0x01 if the corresponding column is part of the tables primary key, or 11303 ** 0x00 if it is not. 11304 ** 11305 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11306 ** in the table. 11307 ** 11308 ** If this function is called when the iterator does not point to a valid 11309 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11310 ** SQLITE_OK is returned and the output variables populated as described 11311 ** above. 11312 */ 11313 SQLITE_API int sqlite3changeset_pk( 11314 sqlite3_changeset_iter *pIter, /* Iterator object */ 11315 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11316 int *pnCol /* OUT: Number of entries in output array */ 11317 ); 11318 11319 /* 11320 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11321 ** METHOD: sqlite3_changeset_iter 11322 ** 11323 ** The pIter argument passed to this function may either be an iterator 11324 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11325 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11326 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11327 ** Furthermore, it may only be called if the type of change that the iterator 11328 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11329 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11330 ** 11331 ** Argument iVal must be greater than or equal to 0, and less than the number 11332 ** of columns in the table affected by the current change. Otherwise, 11333 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11334 ** 11335 ** If successful, this function sets *ppValue to point to a protected 11336 ** sqlite3_value object containing the iVal'th value from the vector of 11337 ** original row values stored as part of the UPDATE or DELETE change and 11338 ** returns SQLITE_OK. The name of the function comes from the fact that this 11339 ** is similar to the "old.*" columns available to update or delete triggers. 11340 ** 11341 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11342 ** is returned and *ppValue is set to NULL. 11343 */ 11344 SQLITE_API int sqlite3changeset_old( 11345 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11346 int iVal, /* Column number */ 11347 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11348 ); 11349 11350 /* 11351 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11352 ** METHOD: sqlite3_changeset_iter 11353 ** 11354 ** The pIter argument passed to this function may either be an iterator 11355 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11356 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 11357 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11358 ** Furthermore, it may only be called if the type of change that the iterator 11359 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11360 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11361 ** 11362 ** Argument iVal must be greater than or equal to 0, and less than the number 11363 ** of columns in the table affected by the current change. Otherwise, 11364 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11365 ** 11366 ** If successful, this function sets *ppValue to point to a protected 11367 ** sqlite3_value object containing the iVal'th value from the vector of 11368 ** new row values stored as part of the UPDATE or INSERT change and 11369 ** returns SQLITE_OK. If the change is an UPDATE and does not include 11370 ** a new value for the requested column, *ppValue is set to NULL and 11371 ** SQLITE_OK returned. The name of the function comes from the fact that 11372 ** this is similar to the "new.*" columns available to update or delete 11373 ** triggers. 11374 ** 11375 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11376 ** is returned and *ppValue is set to NULL. 11377 */ 11378 SQLITE_API int sqlite3changeset_new( 11379 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11380 int iVal, /* Column number */ 11381 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11382 ); 11383 11384 /* 11385 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11386 ** METHOD: sqlite3_changeset_iter 11387 ** 11388 ** This function should only be used with iterator objects passed to a 11389 ** conflict-handler callback by [sqlite3changeset_apply()] with either 11390 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11391 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11392 ** is set to NULL. 11393 ** 11394 ** Argument iVal must be greater than or equal to 0, and less than the number 11395 ** of columns in the table affected by the current change. Otherwise, 11396 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11397 ** 11398 ** If successful, this function sets *ppValue to point to a protected 11399 ** sqlite3_value object containing the iVal'th value from the 11400 ** "conflicting row" associated with the current conflict-handler callback 11401 ** and returns SQLITE_OK. 11402 ** 11403 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 11404 ** is returned and *ppValue is set to NULL. 11405 */ 11406 SQLITE_API int sqlite3changeset_conflict( 11407 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11408 int iVal, /* Column number */ 11409 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11410 ); 11411 11412 /* 11413 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11414 ** METHOD: sqlite3_changeset_iter 11415 ** 11416 ** This function may only be called with an iterator passed to an 11417 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11418 ** it sets the output variable to the total number of known foreign key 11419 ** violations in the destination database and returns SQLITE_OK. 11420 ** 11421 ** In all other cases this function returns SQLITE_MISUSE. 11422 */ 11423 SQLITE_API int sqlite3changeset_fk_conflicts( 11424 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11425 int *pnOut /* OUT: Number of FK violations */ 11426 ); 11427 11428 11429 /* 11430 ** CAPI3REF: Finalize A Changeset Iterator 11431 ** METHOD: sqlite3_changeset_iter 11432 ** 11433 ** This function is used to finalize an iterator allocated with 11434 ** [sqlite3changeset_start()]. 11435 ** 11436 ** This function should only be called on iterators created using the 11437 ** [sqlite3changeset_start()] function. If an application calls this 11438 ** function with an iterator passed to a conflict-handler by 11439 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11440 ** call has no effect. 11441 ** 11442 ** If an error was encountered within a call to an sqlite3changeset_xxx() 11443 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11444 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11445 ** to that error is returned by this function. Otherwise, SQLITE_OK is 11446 ** returned. This is to allow the following pattern (pseudo-code): 11447 ** 11448 ** <pre> 11449 ** sqlite3changeset_start(); 11450 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 11451 ** // Do something with change. 11452 ** } 11453 ** rc = sqlite3changeset_finalize(); 11454 ** if( rc!=SQLITE_OK ){ 11455 ** // An error has occurred 11456 ** } 11457 ** </pre> 11458 */ 11459 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11460 11461 /* 11462 ** CAPI3REF: Invert A Changeset 11463 ** 11464 ** This function is used to "invert" a changeset object. Applying an inverted 11465 ** changeset to a database reverses the effects of applying the uninverted 11466 ** changeset. Specifically: 11467 ** 11468 ** <ul> 11469 ** <li> Each DELETE change is changed to an INSERT, and 11470 ** <li> Each INSERT change is changed to a DELETE, and 11471 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11472 ** </ul> 11473 ** 11474 ** This function does not change the order in which changes appear within 11475 ** the changeset. It merely reverses the sense of each individual change. 11476 ** 11477 ** If successful, a pointer to a buffer containing the inverted changeset 11478 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11479 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11480 ** zeroed and an SQLite error code returned. 11481 ** 11482 ** It is the responsibility of the caller to eventually call sqlite3_free() 11483 ** on the *ppOut pointer to free the buffer allocation following a successful 11484 ** call to this function. 11485 ** 11486 ** WARNING/TODO: This function currently assumes that the input is a valid 11487 ** changeset. If it is not, the results are undefined. 11488 */ 11489 SQLITE_API int sqlite3changeset_invert( 11490 int nIn, const void *pIn, /* Input changeset */ 11491 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11492 ); 11493 11494 /* 11495 ** CAPI3REF: Concatenate Two Changeset Objects 11496 ** 11497 ** This function is used to concatenate two changesets, A and B, into a 11498 ** single changeset. The result is a changeset equivalent to applying 11499 ** changeset A followed by changeset B. 11500 ** 11501 ** This function combines the two input changesets using an 11502 ** sqlite3_changegroup object. Calling it produces similar results as the 11503 ** following code fragment: 11504 ** 11505 ** <pre> 11506 ** sqlite3_changegroup *pGrp; 11507 ** rc = sqlite3_changegroup_new(&pGrp); 11508 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11509 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11510 ** if( rc==SQLITE_OK ){ 11511 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11512 ** }else{ 11513 ** *ppOut = 0; 11514 ** *pnOut = 0; 11515 ** } 11516 ** </pre> 11517 ** 11518 ** Refer to the sqlite3_changegroup documentation below for details. 11519 */ 11520 SQLITE_API int sqlite3changeset_concat( 11521 int nA, /* Number of bytes in buffer pA */ 11522 void *pA, /* Pointer to buffer containing changeset A */ 11523 int nB, /* Number of bytes in buffer pB */ 11524 void *pB, /* Pointer to buffer containing changeset B */ 11525 int *pnOut, /* OUT: Number of bytes in output changeset */ 11526 void **ppOut /* OUT: Buffer containing output changeset */ 11527 ); 11528 11529 11530 /* 11531 ** CAPI3REF: Changegroup Handle 11532 ** 11533 ** A changegroup is an object used to combine two or more 11534 ** [changesets] or [patchsets] 11535 */ 11536 typedef struct sqlite3_changegroup sqlite3_changegroup; 11537 11538 /* 11539 ** CAPI3REF: Create A New Changegroup Object 11540 ** CONSTRUCTOR: sqlite3_changegroup 11541 ** 11542 ** An sqlite3_changegroup object is used to combine two or more changesets 11543 ** (or patchsets) into a single changeset (or patchset). A single changegroup 11544 ** object may combine changesets or patchsets, but not both. The output is 11545 ** always in the same format as the input. 11546 ** 11547 ** If successful, this function returns SQLITE_OK and populates (*pp) with 11548 ** a pointer to a new sqlite3_changegroup object before returning. The caller 11549 ** should eventually free the returned object using a call to 11550 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11551 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11552 ** 11553 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 11554 ** 11555 ** <ul> 11556 ** <li> It is created using a call to sqlite3changegroup_new(). 11557 ** 11558 ** <li> Zero or more changesets (or patchsets) are added to the object 11559 ** by calling sqlite3changegroup_add(). 11560 ** 11561 ** <li> The result of combining all input changesets together is obtained 11562 ** by the application via a call to sqlite3changegroup_output(). 11563 ** 11564 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11565 ** </ul> 11566 ** 11567 ** Any number of calls to add() and output() may be made between the calls to 11568 ** new() and delete(), and in any order. 11569 ** 11570 ** As well as the regular sqlite3changegroup_add() and 11571 ** sqlite3changegroup_output() functions, also available are the streaming 11572 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11573 */ 11574 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11575 11576 /* 11577 ** CAPI3REF: Add A Changeset To A Changegroup 11578 ** METHOD: sqlite3_changegroup 11579 ** 11580 ** Add all changes within the changeset (or patchset) in buffer pData (size 11581 ** nData bytes) to the changegroup. 11582 ** 11583 ** If the buffer contains a patchset, then all prior calls to this function 11584 ** on the same changegroup object must also have specified patchsets. Or, if 11585 ** the buffer contains a changeset, so must have the earlier calls to this 11586 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11587 ** to the changegroup. 11588 ** 11589 ** Rows within the changeset and changegroup are identified by the values in 11590 ** their PRIMARY KEY columns. A change in the changeset is considered to 11591 ** apply to the same row as a change already present in the changegroup if 11592 ** the two rows have the same primary key. 11593 ** 11594 ** Changes to rows that do not already appear in the changegroup are 11595 ** simply copied into it. Or, if both the new changeset and the changegroup 11596 ** contain changes that apply to a single row, the final contents of the 11597 ** changegroup depends on the type of each change, as follows: 11598 ** 11599 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11600 ** <tr><th style="white-space:pre">Existing Change </th> 11601 ** <th style="white-space:pre">New Change </th> 11602 ** <th>Output Change 11603 ** <tr><td>INSERT <td>INSERT <td> 11604 ** The new change is ignored. This case does not occur if the new 11605 ** changeset was recorded immediately after the changesets already 11606 ** added to the changegroup. 11607 ** <tr><td>INSERT <td>UPDATE <td> 11608 ** The INSERT change remains in the changegroup. The values in the 11609 ** INSERT change are modified as if the row was inserted by the 11610 ** existing change and then updated according to the new change. 11611 ** <tr><td>INSERT <td>DELETE <td> 11612 ** The existing INSERT is removed from the changegroup. The DELETE is 11613 ** not added. 11614 ** <tr><td>UPDATE <td>INSERT <td> 11615 ** The new change is ignored. This case does not occur if the new 11616 ** changeset was recorded immediately after the changesets already 11617 ** added to the changegroup. 11618 ** <tr><td>UPDATE <td>UPDATE <td> 11619 ** The existing UPDATE remains within the changegroup. It is amended 11620 ** so that the accompanying values are as if the row was updated once 11621 ** by the existing change and then again by the new change. 11622 ** <tr><td>UPDATE <td>DELETE <td> 11623 ** The existing UPDATE is replaced by the new DELETE within the 11624 ** changegroup. 11625 ** <tr><td>DELETE <td>INSERT <td> 11626 ** If one or more of the column values in the row inserted by the 11627 ** new change differ from those in the row deleted by the existing 11628 ** change, the existing DELETE is replaced by an UPDATE within the 11629 ** changegroup. Otherwise, if the inserted row is exactly the same 11630 ** as the deleted row, the existing DELETE is simply discarded. 11631 ** <tr><td>DELETE <td>UPDATE <td> 11632 ** The new change is ignored. This case does not occur if the new 11633 ** changeset was recorded immediately after the changesets already 11634 ** added to the changegroup. 11635 ** <tr><td>DELETE <td>DELETE <td> 11636 ** The new change is ignored. This case does not occur if the new 11637 ** changeset was recorded immediately after the changesets already 11638 ** added to the changegroup. 11639 ** </table> 11640 ** 11641 ** If the new changeset contains changes to a table that is already present 11642 ** in the changegroup, then the number of columns and the position of the 11643 ** primary key columns for the table must be consistent. If this is not the 11644 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 11645 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 11646 ** returned. Or, if an out-of-memory condition occurs during processing, this 11647 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 11648 ** of the final contents of the changegroup is undefined. 11649 ** 11650 ** If no error occurs, SQLITE_OK is returned. 11651 */ 11652 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11653 11654 /* 11655 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11656 ** METHOD: sqlite3_changegroup 11657 ** 11658 ** Obtain a buffer containing a changeset (or patchset) representing the 11659 ** current contents of the changegroup. If the inputs to the changegroup 11660 ** were themselves changesets, the output is a changeset. Or, if the 11661 ** inputs were patchsets, the output is also a patchset. 11662 ** 11663 ** As with the output of the sqlite3session_changeset() and 11664 ** sqlite3session_patchset() functions, all changes related to a single 11665 ** table are grouped together in the output of this function. Tables appear 11666 ** in the same order as for the very first changeset added to the changegroup. 11667 ** If the second or subsequent changesets added to the changegroup contain 11668 ** changes for tables that do not appear in the first changeset, they are 11669 ** appended onto the end of the output changeset, again in the order in 11670 ** which they are first encountered. 11671 ** 11672 ** If an error occurs, an SQLite error code is returned and the output 11673 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11674 ** is returned and the output variables are set to the size of and a 11675 ** pointer to the output buffer, respectively. In this case it is the 11676 ** responsibility of the caller to eventually free the buffer using a 11677 ** call to sqlite3_free(). 11678 */ 11679 SQLITE_API int sqlite3changegroup_output( 11680 sqlite3_changegroup*, 11681 int *pnData, /* OUT: Size of output buffer in bytes */ 11682 void **ppData /* OUT: Pointer to output buffer */ 11683 ); 11684 11685 /* 11686 ** CAPI3REF: Delete A Changegroup Object 11687 ** DESTRUCTOR: sqlite3_changegroup 11688 */ 11689 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11690 11691 /* 11692 ** CAPI3REF: Apply A Changeset To A Database 11693 ** 11694 ** Apply a changeset or patchset to a database. These functions attempt to 11695 ** update the "main" database attached to handle db with the changes found in 11696 ** the changeset passed via the second and third arguments. 11697 ** 11698 ** The fourth argument (xFilter) passed to these functions is the "filter 11699 ** callback". If it is not NULL, then for each table affected by at least one 11700 ** change in the changeset, the filter callback is invoked with 11701 ** the table name as the second argument, and a copy of the context pointer 11702 ** passed as the sixth argument as the first. If the "filter callback" 11703 ** returns zero, then no attempt is made to apply any changes to the table. 11704 ** Otherwise, if the return value is non-zero or the xFilter argument to 11705 ** is NULL, all changes related to the table are attempted. 11706 ** 11707 ** For each table that is not excluded by the filter callback, this function 11708 ** tests that the target database contains a compatible table. A table is 11709 ** considered compatible if all of the following are true: 11710 ** 11711 ** <ul> 11712 ** <li> The table has the same name as the name recorded in the 11713 ** changeset, and 11714 ** <li> The table has at least as many columns as recorded in the 11715 ** changeset, and 11716 ** <li> The table has primary key columns in the same position as 11717 ** recorded in the changeset. 11718 ** </ul> 11719 ** 11720 ** If there is no compatible table, it is not an error, but none of the 11721 ** changes associated with the table are applied. A warning message is issued 11722 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11723 ** one such warning is issued for each table in the changeset. 11724 ** 11725 ** For each change for which there is a compatible table, an attempt is made 11726 ** to modify the table contents according to the UPDATE, INSERT or DELETE 11727 ** change. If a change cannot be applied cleanly, the conflict handler 11728 ** function passed as the fifth argument to sqlite3changeset_apply() may be 11729 ** invoked. A description of exactly when the conflict handler is invoked for 11730 ** each type of change is below. 11731 ** 11732 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11733 ** of passing anything other than a valid function pointer as the xConflict 11734 ** argument are undefined. 11735 ** 11736 ** Each time the conflict handler function is invoked, it must return one 11737 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11738 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11739 ** if the second argument passed to the conflict handler is either 11740 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11741 ** returns an illegal value, any changes already made are rolled back and 11742 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11743 ** actions are taken by sqlite3changeset_apply() depending on the value 11744 ** returned by each invocation of the conflict-handler function. Refer to 11745 ** the documentation for the three 11746 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 11747 ** 11748 ** <dl> 11749 ** <dt>DELETE Changes<dd> 11750 ** For each DELETE change, the function checks if the target database 11751 ** contains a row with the same primary key value (or values) as the 11752 ** original row values stored in the changeset. If it does, and the values 11753 ** stored in all non-primary key columns also match the values stored in 11754 ** the changeset the row is deleted from the target database. 11755 ** 11756 ** If a row with matching primary key values is found, but one or more of 11757 ** the non-primary key fields contains a value different from the original 11758 ** row value stored in the changeset, the conflict-handler function is 11759 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11760 ** database table has more columns than are recorded in the changeset, 11761 ** only the values of those non-primary key fields are compared against 11762 ** the current database contents - any trailing database table columns 11763 ** are ignored. 11764 ** 11765 ** If no row with matching primary key values is found in the database, 11766 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11767 ** passed as the second argument. 11768 ** 11769 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11770 ** (which can only happen if a foreign key constraint is violated), the 11771 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11772 ** passed as the second argument. This includes the case where the DELETE 11773 ** operation is attempted because an earlier call to the conflict handler 11774 ** function returned [SQLITE_CHANGESET_REPLACE]. 11775 ** 11776 ** <dt>INSERT Changes<dd> 11777 ** For each INSERT change, an attempt is made to insert the new row into 11778 ** the database. If the changeset row contains fewer fields than the 11779 ** database table, the trailing fields are populated with their default 11780 ** values. 11781 ** 11782 ** If the attempt to insert the row fails because the database already 11783 ** contains a row with the same primary key values, the conflict handler 11784 ** function is invoked with the second argument set to 11785 ** [SQLITE_CHANGESET_CONFLICT]. 11786 ** 11787 ** If the attempt to insert the row fails because of some other constraint 11788 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11789 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11790 ** This includes the case where the INSERT operation is re-attempted because 11791 ** an earlier call to the conflict handler function returned 11792 ** [SQLITE_CHANGESET_REPLACE]. 11793 ** 11794 ** <dt>UPDATE Changes<dd> 11795 ** For each UPDATE change, the function checks if the target database 11796 ** contains a row with the same primary key value (or values) as the 11797 ** original row values stored in the changeset. If it does, and the values 11798 ** stored in all modified non-primary key columns also match the values 11799 ** stored in the changeset the row is updated within the target database. 11800 ** 11801 ** If a row with matching primary key values is found, but one or more of 11802 ** the modified non-primary key fields contains a value different from an 11803 ** original row value stored in the changeset, the conflict-handler function 11804 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11805 ** UPDATE changes only contain values for non-primary key fields that are 11806 ** to be modified, only those fields need to match the original values to 11807 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11808 ** 11809 ** If no row with matching primary key values is found in the database, 11810 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11811 ** passed as the second argument. 11812 ** 11813 ** If the UPDATE operation is attempted, but SQLite returns 11814 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11815 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11816 ** This includes the case where the UPDATE operation is attempted after 11817 ** an earlier call to the conflict handler function returned 11818 ** [SQLITE_CHANGESET_REPLACE]. 11819 ** </dl> 11820 ** 11821 ** It is safe to execute SQL statements, including those that write to the 11822 ** table that the callback related to, from within the xConflict callback. 11823 ** This can be used to further customize the application's conflict 11824 ** resolution strategy. 11825 ** 11826 ** All changes made by these functions are enclosed in a savepoint transaction. 11827 ** If any other error (aside from a constraint failure when attempting to 11828 ** write to the target database) occurs, then the savepoint transaction is 11829 ** rolled back, restoring the target database to its original state, and an 11830 ** SQLite error code returned. 11831 ** 11832 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11833 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11834 ** may set (*ppRebase) to point to a "rebase" that may be used with the 11835 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11836 ** is set to the size of the buffer in bytes. It is the responsibility of the 11837 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 11838 ** is only allocated and populated if one or more conflicts were encountered 11839 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 11840 ** APIs for further details. 11841 ** 11842 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11843 ** may be modified by passing a combination of 11844 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11845 ** 11846 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11847 ** and therefore subject to change. 11848 */ 11849 SQLITE_API int sqlite3changeset_apply( 11850 sqlite3 *db, /* Apply change to "main" db of this handle */ 11851 int nChangeset, /* Size of changeset in bytes */ 11852 void *pChangeset, /* Changeset blob */ 11853 int(*xFilter)( 11854 void *pCtx, /* Copy of sixth arg to _apply() */ 11855 const char *zTab /* Table name */ 11856 ), 11857 int(*xConflict)( 11858 void *pCtx, /* Copy of sixth arg to _apply() */ 11859 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11860 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11861 ), 11862 void *pCtx /* First argument passed to xConflict */ 11863 ); 11864 SQLITE_API int sqlite3changeset_apply_v2( 11865 sqlite3 *db, /* Apply change to "main" db of this handle */ 11866 int nChangeset, /* Size of changeset in bytes */ 11867 void *pChangeset, /* Changeset blob */ 11868 int(*xFilter)( 11869 void *pCtx, /* Copy of sixth arg to _apply() */ 11870 const char *zTab /* Table name */ 11871 ), 11872 int(*xConflict)( 11873 void *pCtx, /* Copy of sixth arg to _apply() */ 11874 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11875 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11876 ), 11877 void *pCtx, /* First argument passed to xConflict */ 11878 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11879 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11880 ); 11881 11882 /* 11883 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 11884 ** 11885 ** The following flags may passed via the 9th parameter to 11886 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11887 ** 11888 ** <dl> 11889 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11890 ** Usually, the sessions module encloses all operations performed by 11891 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11892 ** SAVEPOINT is committed if the changeset or patchset is successfully 11893 ** applied, or rolled back if an error occurs. Specifying this flag 11894 ** causes the sessions module to omit this savepoint. In this case, if the 11895 ** caller has an open transaction or savepoint when apply_v2() is called, 11896 ** it may revert the partially applied changeset by rolling it back. 11897 ** 11898 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11899 ** Invert the changeset before applying it. This is equivalent to inverting 11900 ** a changeset using sqlite3changeset_invert() before applying it. It is 11901 ** an error to specify this flag with a patchset. 11902 */ 11903 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11904 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11905 11906 /* 11907 ** CAPI3REF: Constants Passed To The Conflict Handler 11908 ** 11909 ** Values that may be passed as the second argument to a conflict-handler. 11910 ** 11911 ** <dl> 11912 ** <dt>SQLITE_CHANGESET_DATA<dd> 11913 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 11914 ** when processing a DELETE or UPDATE change if a row with the required 11915 ** PRIMARY KEY fields is present in the database, but one or more other 11916 ** (non primary-key) fields modified by the update do not contain the 11917 ** expected "before" values. 11918 ** 11919 ** The conflicting row, in this case, is the database row with the matching 11920 ** primary key. 11921 ** 11922 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11923 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11924 ** argument when processing a DELETE or UPDATE change if a row with the 11925 ** required PRIMARY KEY fields is not present in the database. 11926 ** 11927 ** There is no conflicting row in this case. The results of invoking the 11928 ** sqlite3changeset_conflict() API are undefined. 11929 ** 11930 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11931 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 11932 ** handler while processing an INSERT change if the operation would result 11933 ** in duplicate primary key values. 11934 ** 11935 ** The conflicting row in this case is the database row with the matching 11936 ** primary key. 11937 ** 11938 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11939 ** If foreign key handling is enabled, and applying a changeset leaves the 11940 ** database in a state containing foreign key violations, the conflict 11941 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11942 ** exactly once before the changeset is committed. If the conflict handler 11943 ** returns CHANGESET_OMIT, the changes, including those that caused the 11944 ** foreign key constraint violation, are committed. Or, if it returns 11945 ** CHANGESET_ABORT, the changeset is rolled back. 11946 ** 11947 ** No current or conflicting row information is provided. The only function 11948 ** it is possible to call on the supplied sqlite3_changeset_iter handle 11949 ** is sqlite3changeset_fk_conflicts(). 11950 ** 11951 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11952 ** If any other constraint violation occurs while applying a change (i.e. 11953 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11954 ** invoked with CHANGESET_CONSTRAINT as the second argument. 11955 ** 11956 ** There is no conflicting row in this case. The results of invoking the 11957 ** sqlite3changeset_conflict() API are undefined. 11958 ** 11959 ** </dl> 11960 */ 11961 #define SQLITE_CHANGESET_DATA 1 11962 #define SQLITE_CHANGESET_NOTFOUND 2 11963 #define SQLITE_CHANGESET_CONFLICT 3 11964 #define SQLITE_CHANGESET_CONSTRAINT 4 11965 #define SQLITE_CHANGESET_FOREIGN_KEY 5 11966 11967 /* 11968 ** CAPI3REF: Constants Returned By The Conflict Handler 11969 ** 11970 ** A conflict handler callback must return one of the following three values. 11971 ** 11972 ** <dl> 11973 ** <dt>SQLITE_CHANGESET_OMIT<dd> 11974 ** If a conflict handler returns this value no special action is taken. The 11975 ** change that caused the conflict is not applied. The session module 11976 ** continues to the next change in the changeset. 11977 ** 11978 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 11979 ** This value may only be returned if the second argument to the conflict 11980 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11981 ** is not the case, any changes applied so far are rolled back and the 11982 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11983 ** 11984 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11985 ** handler, then the conflicting row is either updated or deleted, depending 11986 ** on the type of change. 11987 ** 11988 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11989 ** handler, then the conflicting row is removed from the database and a 11990 ** second attempt to apply the change is made. If this second attempt fails, 11991 ** the original row is restored to the database before continuing. 11992 ** 11993 ** <dt>SQLITE_CHANGESET_ABORT<dd> 11994 ** If this value is returned, any changes applied so far are rolled back 11995 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11996 ** </dl> 11997 */ 11998 #define SQLITE_CHANGESET_OMIT 0 11999 #define SQLITE_CHANGESET_REPLACE 1 12000 #define SQLITE_CHANGESET_ABORT 2 12001 12002 /* 12003 ** CAPI3REF: Rebasing changesets 12004 ** EXPERIMENTAL 12005 ** 12006 ** Suppose there is a site hosting a database in state S0. And that 12007 ** modifications are made that move that database to state S1 and a 12008 ** changeset recorded (the "local" changeset). Then, a changeset based 12009 ** on S0 is received from another site (the "remote" changeset) and 12010 ** applied to the database. The database is then in state 12011 ** (S1+"remote"), where the exact state depends on any conflict 12012 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 12013 ** Rebasing a changeset is to update it to take those conflict 12014 ** resolution decisions into account, so that the same conflicts 12015 ** do not have to be resolved elsewhere in the network. 12016 ** 12017 ** For example, if both the local and remote changesets contain an 12018 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12019 ** 12020 ** local: INSERT INTO t1 VALUES(1, 'v1'); 12021 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 12022 ** 12023 ** and the conflict resolution is REPLACE, then the INSERT change is 12024 ** removed from the local changeset (it was overridden). Or, if the 12025 ** conflict resolution was "OMIT", then the local changeset is modified 12026 ** to instead contain: 12027 ** 12028 ** UPDATE t1 SET b = 'v2' WHERE a=1; 12029 ** 12030 ** Changes within the local changeset are rebased as follows: 12031 ** 12032 ** <dl> 12033 ** <dt>Local INSERT<dd> 12034 ** This may only conflict with a remote INSERT. If the conflict 12035 ** resolution was OMIT, then add an UPDATE change to the rebased 12036 ** changeset. Or, if the conflict resolution was REPLACE, add 12037 ** nothing to the rebased changeset. 12038 ** 12039 ** <dt>Local DELETE<dd> 12040 ** This may conflict with a remote UPDATE or DELETE. In both cases the 12041 ** only possible resolution is OMIT. If the remote operation was a 12042 ** DELETE, then add no change to the rebased changeset. If the remote 12043 ** operation was an UPDATE, then the old.* fields of change are updated 12044 ** to reflect the new.* values in the UPDATE. 12045 ** 12046 ** <dt>Local UPDATE<dd> 12047 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 12048 ** with a DELETE, and the conflict resolution was OMIT, then the update 12049 ** is changed into an INSERT. Any undefined values in the new.* record 12050 ** from the update change are filled in using the old.* values from 12051 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12052 ** the UPDATE change is simply omitted from the rebased changeset. 12053 ** 12054 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 12055 ** the old.* values are rebased using the new.* values in the remote 12056 ** change. Or, if the resolution is REPLACE, then the change is copied 12057 ** into the rebased changeset with updates to columns also updated by 12058 ** the conflicting remote UPDATE removed. If this means no columns would 12059 ** be updated, the change is omitted. 12060 ** </dl> 12061 ** 12062 ** A local change may be rebased against multiple remote changes 12063 ** simultaneously. If a single key is modified by multiple remote 12064 ** changesets, they are combined as follows before the local changeset 12065 ** is rebased: 12066 ** 12067 ** <ul> 12068 ** <li> If there has been one or more REPLACE resolutions on a 12069 ** key, it is rebased according to a REPLACE. 12070 ** 12071 ** <li> If there have been no REPLACE resolutions on a key, then 12072 ** the local changeset is rebased according to the most recent 12073 ** of the OMIT resolutions. 12074 ** </ul> 12075 ** 12076 ** Note that conflict resolutions from multiple remote changesets are 12077 ** combined on a per-field basis, not per-row. This means that in the 12078 ** case of multiple remote UPDATE operations, some fields of a single 12079 ** local change may be rebased for REPLACE while others are rebased for 12080 ** OMIT. 12081 ** 12082 ** In order to rebase a local changeset, the remote changeset must first 12083 ** be applied to the local database using sqlite3changeset_apply_v2() and 12084 ** the buffer of rebase information captured. Then: 12085 ** 12086 ** <ol> 12087 ** <li> An sqlite3_rebaser object is created by calling 12088 ** sqlite3rebaser_create(). 12089 ** <li> The new object is configured with the rebase buffer obtained from 12090 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12091 ** If the local changeset is to be rebased against multiple remote 12092 ** changesets, then sqlite3rebaser_configure() should be called 12093 ** multiple times, in the same order that the multiple 12094 ** sqlite3changeset_apply_v2() calls were made. 12095 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12096 ** <li> The sqlite3_rebaser object is deleted by calling 12097 ** sqlite3rebaser_delete(). 12098 ** </ol> 12099 */ 12100 typedef struct sqlite3_rebaser sqlite3_rebaser; 12101 12102 /* 12103 ** CAPI3REF: Create a changeset rebaser object. 12104 ** EXPERIMENTAL 12105 ** 12106 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12107 ** point to the new object and return SQLITE_OK. Otherwise, if an error 12108 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12109 ** to NULL. 12110 */ 12111 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12112 12113 /* 12114 ** CAPI3REF: Configure a changeset rebaser object. 12115 ** EXPERIMENTAL 12116 ** 12117 ** Configure the changeset rebaser object to rebase changesets according 12118 ** to the conflict resolutions described by buffer pRebase (size nRebase 12119 ** bytes), which must have been obtained from a previous call to 12120 ** sqlite3changeset_apply_v2(). 12121 */ 12122 SQLITE_API int sqlite3rebaser_configure( 12123 sqlite3_rebaser*, 12124 int nRebase, const void *pRebase 12125 ); 12126 12127 /* 12128 ** CAPI3REF: Rebase a changeset 12129 ** EXPERIMENTAL 12130 ** 12131 ** Argument pIn must point to a buffer containing a changeset nIn bytes 12132 ** in size. This function allocates and populates a buffer with a copy 12133 ** of the changeset rebased according to the configuration of the 12134 ** rebaser object passed as the first argument. If successful, (*ppOut) 12135 ** is set to point to the new buffer containing the rebased changeset and 12136 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12137 ** responsibility of the caller to eventually free the new buffer using 12138 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12139 ** are set to zero and an SQLite error code returned. 12140 */ 12141 SQLITE_API int sqlite3rebaser_rebase( 12142 sqlite3_rebaser*, 12143 int nIn, const void *pIn, 12144 int *pnOut, void **ppOut 12145 ); 12146 12147 /* 12148 ** CAPI3REF: Delete a changeset rebaser object. 12149 ** EXPERIMENTAL 12150 ** 12151 ** Delete the changeset rebaser object and all associated resources. There 12152 ** should be one call to this function for each successful invocation 12153 ** of sqlite3rebaser_create(). 12154 */ 12155 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12156 12157 /* 12158 ** CAPI3REF: Streaming Versions of API functions. 12159 ** 12160 ** The six streaming API xxx_strm() functions serve similar purposes to the 12161 ** corresponding non-streaming API functions: 12162 ** 12163 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12164 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12165 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12166 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12167 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12168 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12169 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12170 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12171 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12172 ** </table> 12173 ** 12174 ** Non-streaming functions that accept changesets (or patchsets) as input 12175 ** require that the entire changeset be stored in a single buffer in memory. 12176 ** Similarly, those that return a changeset or patchset do so by returning 12177 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 12178 ** Normally this is convenient. However, if an application running in a 12179 ** low-memory environment is required to handle very large changesets, the 12180 ** large contiguous memory allocations required can become onerous. 12181 ** 12182 ** In order to avoid this problem, instead of a single large buffer, input 12183 ** is passed to a streaming API functions by way of a callback function that 12184 ** the sessions module invokes to incrementally request input data as it is 12185 ** required. In all cases, a pair of API function parameters such as 12186 ** 12187 ** <pre> 12188 ** int nChangeset, 12189 ** void *pChangeset, 12190 ** </pre> 12191 ** 12192 ** Is replaced by: 12193 ** 12194 ** <pre> 12195 ** int (*xInput)(void *pIn, void *pData, int *pnData), 12196 ** void *pIn, 12197 ** </pre> 12198 ** 12199 ** Each time the xInput callback is invoked by the sessions module, the first 12200 ** argument passed is a copy of the supplied pIn context pointer. The second 12201 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12202 ** error occurs the xInput method should copy up to (*pnData) bytes of data 12203 ** into the buffer and set (*pnData) to the actual number of bytes copied 12204 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12205 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12206 ** error code should be returned. In all cases, if an xInput callback returns 12207 ** an error, all processing is abandoned and the streaming API function 12208 ** returns a copy of the error code to the caller. 12209 ** 12210 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12211 ** invoked by the sessions module at any point during the lifetime of the 12212 ** iterator. If such an xInput callback returns an error, the iterator enters 12213 ** an error state, whereby all subsequent calls to iterator functions 12214 ** immediately fail with the same error code as returned by xInput. 12215 ** 12216 ** Similarly, streaming API functions that return changesets (or patchsets) 12217 ** return them in chunks by way of a callback function instead of via a 12218 ** pointer to a single large buffer. In this case, a pair of parameters such 12219 ** as: 12220 ** 12221 ** <pre> 12222 ** int *pnChangeset, 12223 ** void **ppChangeset, 12224 ** </pre> 12225 ** 12226 ** Is replaced by: 12227 ** 12228 ** <pre> 12229 ** int (*xOutput)(void *pOut, const void *pData, int nData), 12230 ** void *pOut 12231 ** </pre> 12232 ** 12233 ** The xOutput callback is invoked zero or more times to return data to 12234 ** the application. The first parameter passed to each call is a copy of the 12235 ** pOut pointer supplied by the application. The second parameter, pData, 12236 ** points to a buffer nData bytes in size containing the chunk of output 12237 ** data being returned. If the xOutput callback successfully processes the 12238 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12239 ** it should return some other SQLite error code. In this case processing 12240 ** is immediately abandoned and the streaming API function returns a copy 12241 ** of the xOutput error code to the application. 12242 ** 12243 ** The sessions module never invokes an xOutput callback with the third 12244 ** parameter set to a value less than or equal to zero. Other than this, 12245 ** no guarantees are made as to the size of the chunks of data returned. 12246 */ 12247 SQLITE_API int sqlite3changeset_apply_strm( 12248 sqlite3 *db, /* Apply change to "main" db of this handle */ 12249 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12250 void *pIn, /* First arg for xInput */ 12251 int(*xFilter)( 12252 void *pCtx, /* Copy of sixth arg to _apply() */ 12253 const char *zTab /* Table name */ 12254 ), 12255 int(*xConflict)( 12256 void *pCtx, /* Copy of sixth arg to _apply() */ 12257 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12258 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12259 ), 12260 void *pCtx /* First argument passed to xConflict */ 12261 ); 12262 SQLITE_API int sqlite3changeset_apply_v2_strm( 12263 sqlite3 *db, /* Apply change to "main" db of this handle */ 12264 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12265 void *pIn, /* First arg for xInput */ 12266 int(*xFilter)( 12267 void *pCtx, /* Copy of sixth arg to _apply() */ 12268 const char *zTab /* Table name */ 12269 ), 12270 int(*xConflict)( 12271 void *pCtx, /* Copy of sixth arg to _apply() */ 12272 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12273 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12274 ), 12275 void *pCtx, /* First argument passed to xConflict */ 12276 void **ppRebase, int *pnRebase, 12277 int flags 12278 ); 12279 SQLITE_API int sqlite3changeset_concat_strm( 12280 int (*xInputA)(void *pIn, void *pData, int *pnData), 12281 void *pInA, 12282 int (*xInputB)(void *pIn, void *pData, int *pnData), 12283 void *pInB, 12284 int (*xOutput)(void *pOut, const void *pData, int nData), 12285 void *pOut 12286 ); 12287 SQLITE_API int sqlite3changeset_invert_strm( 12288 int (*xInput)(void *pIn, void *pData, int *pnData), 12289 void *pIn, 12290 int (*xOutput)(void *pOut, const void *pData, int nData), 12291 void *pOut 12292 ); 12293 SQLITE_API int sqlite3changeset_start_strm( 12294 sqlite3_changeset_iter **pp, 12295 int (*xInput)(void *pIn, void *pData, int *pnData), 12296 void *pIn 12297 ); 12298 SQLITE_API int sqlite3changeset_start_v2_strm( 12299 sqlite3_changeset_iter **pp, 12300 int (*xInput)(void *pIn, void *pData, int *pnData), 12301 void *pIn, 12302 int flags 12303 ); 12304 SQLITE_API int sqlite3session_changeset_strm( 12305 sqlite3_session *pSession, 12306 int (*xOutput)(void *pOut, const void *pData, int nData), 12307 void *pOut 12308 ); 12309 SQLITE_API int sqlite3session_patchset_strm( 12310 sqlite3_session *pSession, 12311 int (*xOutput)(void *pOut, const void *pData, int nData), 12312 void *pOut 12313 ); 12314 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12315 int (*xInput)(void *pIn, void *pData, int *pnData), 12316 void *pIn 12317 ); 12318 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12319 int (*xOutput)(void *pOut, const void *pData, int nData), 12320 void *pOut 12321 ); 12322 SQLITE_API int sqlite3rebaser_rebase_strm( 12323 sqlite3_rebaser *pRebaser, 12324 int (*xInput)(void *pIn, void *pData, int *pnData), 12325 void *pIn, 12326 int (*xOutput)(void *pOut, const void *pData, int nData), 12327 void *pOut 12328 ); 12329 12330 /* 12331 ** CAPI3REF: Configure global parameters 12332 ** 12333 ** The sqlite3session_config() interface is used to make global configuration 12334 ** changes to the sessions module in order to tune it to the specific needs 12335 ** of the application. 12336 ** 12337 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 12338 ** while any other thread is inside any other sessions method then the 12339 ** results are undefined. Furthermore, if it is invoked after any sessions 12340 ** related objects have been created, the results are also undefined. 12341 ** 12342 ** The first argument to the sqlite3session_config() function must be one 12343 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12344 ** interpretation of the (void*) value passed as the second parameter and 12345 ** the effect of calling this function depends on the value of the first 12346 ** parameter. 12347 ** 12348 ** <dl> 12349 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12350 ** By default, the sessions module streaming interfaces attempt to input 12351 ** and output data in approximately 1 KiB chunks. This operand may be used 12352 ** to set and query the value of this configuration setting. The pointer 12353 ** passed as the second argument must point to a value of type (int). 12354 ** If this value is greater than 0, it is used as the new streaming data 12355 ** chunk size for both input and output. Before returning, the (int) value 12356 ** pointed to by pArg is set to the final value of the streaming interface 12357 ** chunk size. 12358 ** </dl> 12359 ** 12360 ** This function returns SQLITE_OK if successful, or an SQLite error code 12361 ** otherwise. 12362 */ 12363 SQLITE_API int sqlite3session_config(int op, void *pArg); 12364 12365 /* 12366 ** CAPI3REF: Values for sqlite3session_config(). 12367 */ 12368 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 12369 12370 /* 12371 ** Make sure we can call this stuff from C++. 12372 */ 12373 #ifdef __cplusplus 12374 } 12375 #endif 12376 12377 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12378 12379 /******** End of sqlite3session.h *********/ 12380 /******** Begin file fts5.h *********/ 12381 /* 12382 ** 2014 May 31 12383 ** 12384 ** The author disclaims copyright to this source code. In place of 12385 ** a legal notice, here is a blessing: 12386 ** 12387 ** May you do good and not evil. 12388 ** May you find forgiveness for yourself and forgive others. 12389 ** May you share freely, never taking more than you give. 12390 ** 12391 ****************************************************************************** 12392 ** 12393 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 12394 ** FTS5 may be extended with: 12395 ** 12396 ** * custom tokenizers, and 12397 ** * custom auxiliary functions. 12398 */ 12399 12400 12401 #ifndef _FTS5_H 12402 #define _FTS5_H 12403 12404 12405 #ifdef __cplusplus 12406 extern "C" { 12407 #endif 12408 12409 /************************************************************************* 12410 ** CUSTOM AUXILIARY FUNCTIONS 12411 ** 12412 ** Virtual table implementations may overload SQL functions by implementing 12413 ** the sqlite3_module.xFindFunction() method. 12414 */ 12415 12416 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12417 typedef struct Fts5Context Fts5Context; 12418 typedef struct Fts5PhraseIter Fts5PhraseIter; 12419 12420 typedef void (*fts5_extension_function)( 12421 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12422 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12423 sqlite3_context *pCtx, /* Context for returning result/error */ 12424 int nVal, /* Number of values in apVal[] array */ 12425 sqlite3_value **apVal /* Array of trailing arguments */ 12426 ); 12427 12428 struct Fts5PhraseIter { 12429 const unsigned char *a; 12430 const unsigned char *b; 12431 }; 12432 12433 /* 12434 ** EXTENSION API FUNCTIONS 12435 ** 12436 ** xUserData(pFts): 12437 ** Return a copy of the context pointer the extension function was 12438 ** registered with. 12439 ** 12440 ** xColumnTotalSize(pFts, iCol, pnToken): 12441 ** If parameter iCol is less than zero, set output variable *pnToken 12442 ** to the total number of tokens in the FTS5 table. Or, if iCol is 12443 ** non-negative but less than the number of columns in the table, return 12444 ** the total number of tokens in column iCol, considering all rows in 12445 ** the FTS5 table. 12446 ** 12447 ** If parameter iCol is greater than or equal to the number of columns 12448 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12449 ** an OOM condition or IO error), an appropriate SQLite error code is 12450 ** returned. 12451 ** 12452 ** xColumnCount(pFts): 12453 ** Return the number of columns in the table. 12454 ** 12455 ** xColumnSize(pFts, iCol, pnToken): 12456 ** If parameter iCol is less than zero, set output variable *pnToken 12457 ** to the total number of tokens in the current row. Or, if iCol is 12458 ** non-negative but less than the number of columns in the table, set 12459 ** *pnToken to the number of tokens in column iCol of the current row. 12460 ** 12461 ** If parameter iCol is greater than or equal to the number of columns 12462 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12463 ** an OOM condition or IO error), an appropriate SQLite error code is 12464 ** returned. 12465 ** 12466 ** This function may be quite inefficient if used with an FTS5 table 12467 ** created with the "columnsize=0" option. 12468 ** 12469 ** xColumnText: 12470 ** This function attempts to retrieve the text of column iCol of the 12471 ** current document. If successful, (*pz) is set to point to a buffer 12472 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12473 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12474 ** if an error occurs, an SQLite error code is returned and the final values 12475 ** of (*pz) and (*pn) are undefined. 12476 ** 12477 ** xPhraseCount: 12478 ** Returns the number of phrases in the current query expression. 12479 ** 12480 ** xPhraseSize: 12481 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 12482 ** are numbered starting from zero. 12483 ** 12484 ** xInstCount: 12485 ** Set *pnInst to the total number of occurrences of all phrases within 12486 ** the query within the current row. Return SQLITE_OK if successful, or 12487 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12488 ** 12489 ** This API can be quite slow if used with an FTS5 table created with the 12490 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12491 ** with either "detail=none" or "detail=column" and "content=" option 12492 ** (i.e. if it is a contentless table), then this API always returns 0. 12493 ** 12494 ** xInst: 12495 ** Query for the details of phrase match iIdx within the current row. 12496 ** Phrase matches are numbered starting from zero, so the iIdx argument 12497 ** should be greater than or equal to zero and smaller than the value 12498 ** output by xInstCount(). 12499 ** 12500 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12501 ** to the column in which it occurs and *piOff the token offset of the 12502 ** first token of the phrase. Returns SQLITE_OK if successful, or an error 12503 ** code (i.e. SQLITE_NOMEM) if an error occurs. 12504 ** 12505 ** This API can be quite slow if used with an FTS5 table created with the 12506 ** "detail=none" or "detail=column" option. 12507 ** 12508 ** xRowid: 12509 ** Returns the rowid of the current row. 12510 ** 12511 ** xTokenize: 12512 ** Tokenize text using the tokenizer belonging to the FTS5 table. 12513 ** 12514 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12515 ** This API function is used to query the FTS table for phrase iPhrase 12516 ** of the current query. Specifically, a query equivalent to: 12517 ** 12518 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12519 ** 12520 ** with $p set to a phrase equivalent to the phrase iPhrase of the 12521 ** current query is executed. Any column filter that applies to 12522 ** phrase iPhrase of the current query is included in $p. For each 12523 ** row visited, the callback function passed as the fourth argument 12524 ** is invoked. The context and API objects passed to the callback 12525 ** function may be used to access the properties of each matched row. 12526 ** Invoking Api.xUserData() returns a copy of the pointer passed as 12527 ** the third argument to pUserData. 12528 ** 12529 ** If the callback function returns any value other than SQLITE_OK, the 12530 ** query is abandoned and the xQueryPhrase function returns immediately. 12531 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12532 ** Otherwise, the error code is propagated upwards. 12533 ** 12534 ** If the query runs to completion without incident, SQLITE_OK is returned. 12535 ** Or, if some error occurs before the query completes or is aborted by 12536 ** the callback, an SQLite error code is returned. 12537 ** 12538 ** 12539 ** xSetAuxdata(pFts5, pAux, xDelete) 12540 ** 12541 ** Save the pointer passed as the second argument as the extension function's 12542 ** "auxiliary data". The pointer may then be retrieved by the current or any 12543 ** future invocation of the same fts5 extension function made as part of 12544 ** the same MATCH query using the xGetAuxdata() API. 12545 ** 12546 ** Each extension function is allocated a single auxiliary data slot for 12547 ** each FTS query (MATCH expression). If the extension function is invoked 12548 ** more than once for a single FTS query, then all invocations share a 12549 ** single auxiliary data context. 12550 ** 12551 ** If there is already an auxiliary data pointer when this function is 12552 ** invoked, then it is replaced by the new pointer. If an xDelete callback 12553 ** was specified along with the original pointer, it is invoked at this 12554 ** point. 12555 ** 12556 ** The xDelete callback, if one is specified, is also invoked on the 12557 ** auxiliary data pointer after the FTS5 query has finished. 12558 ** 12559 ** If an error (e.g. an OOM condition) occurs within this function, 12560 ** the auxiliary data is set to NULL and an error code returned. If the 12561 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 12562 ** pointer before returning. 12563 ** 12564 ** 12565 ** xGetAuxdata(pFts5, bClear) 12566 ** 12567 ** Returns the current auxiliary data pointer for the fts5 extension 12568 ** function. See the xSetAuxdata() method for details. 12569 ** 12570 ** If the bClear argument is non-zero, then the auxiliary data is cleared 12571 ** (set to NULL) before this function returns. In this case the xDelete, 12572 ** if any, is not invoked. 12573 ** 12574 ** 12575 ** xRowCount(pFts5, pnRow) 12576 ** 12577 ** This function is used to retrieve the total number of rows in the table. 12578 ** In other words, the same value that would be returned by: 12579 ** 12580 ** SELECT count(*) FROM ftstable; 12581 ** 12582 ** xPhraseFirst() 12583 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12584 ** method, to iterate through all instances of a single query phrase within 12585 ** the current row. This is the same information as is accessible via the 12586 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12587 ** to use, this API may be faster under some circumstances. To iterate 12588 ** through instances of phrase iPhrase, use the following code: 12589 ** 12590 ** Fts5PhraseIter iter; 12591 ** int iCol, iOff; 12592 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12593 ** iCol>=0; 12594 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12595 ** ){ 12596 ** // An instance of phrase iPhrase at offset iOff of column iCol 12597 ** } 12598 ** 12599 ** The Fts5PhraseIter structure is defined above. Applications should not 12600 ** modify this structure directly - it should only be used as shown above 12601 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 12602 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12603 ** 12604 ** This API can be quite slow if used with an FTS5 table created with the 12605 ** "detail=none" or "detail=column" option. If the FTS5 table is created 12606 ** with either "detail=none" or "detail=column" and "content=" option 12607 ** (i.e. if it is a contentless table), then this API always iterates 12608 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12609 ** 12610 ** xPhraseNext() 12611 ** See xPhraseFirst above. 12612 ** 12613 ** xPhraseFirstColumn() 12614 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12615 ** and xPhraseNext() APIs described above. The difference is that instead 12616 ** of iterating through all instances of a phrase in the current row, these 12617 ** APIs are used to iterate through the set of columns in the current row 12618 ** that contain one or more instances of a specified phrase. For example: 12619 ** 12620 ** Fts5PhraseIter iter; 12621 ** int iCol; 12622 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12623 ** iCol>=0; 12624 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12625 ** ){ 12626 ** // Column iCol contains at least one instance of phrase iPhrase 12627 ** } 12628 ** 12629 ** This API can be quite slow if used with an FTS5 table created with the 12630 ** "detail=none" option. If the FTS5 table is created with either 12631 ** "detail=none" "content=" option (i.e. if it is a contentless table), 12632 ** then this API always iterates through an empty set (all calls to 12633 ** xPhraseFirstColumn() set iCol to -1). 12634 ** 12635 ** The information accessed using this API and its companion 12636 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12637 ** (or xInst/xInstCount). The chief advantage of this API is that it is 12638 ** significantly more efficient than those alternatives when used with 12639 ** "detail=column" tables. 12640 ** 12641 ** xPhraseNextColumn() 12642 ** See xPhraseFirstColumn above. 12643 */ 12644 struct Fts5ExtensionApi { 12645 int iVersion; /* Currently always set to 3 */ 12646 12647 void *(*xUserData)(Fts5Context*); 12648 12649 int (*xColumnCount)(Fts5Context*); 12650 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12651 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12652 12653 int (*xTokenize)(Fts5Context*, 12654 const char *pText, int nText, /* Text to tokenize */ 12655 void *pCtx, /* Context passed to xToken() */ 12656 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12657 ); 12658 12659 int (*xPhraseCount)(Fts5Context*); 12660 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12661 12662 int (*xInstCount)(Fts5Context*, int *pnInst); 12663 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12664 12665 sqlite3_int64 (*xRowid)(Fts5Context*); 12666 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12667 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12668 12669 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12670 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12671 ); 12672 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12673 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12674 12675 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12676 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12677 12678 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12679 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12680 }; 12681 12682 /* 12683 ** CUSTOM AUXILIARY FUNCTIONS 12684 *************************************************************************/ 12685 12686 /************************************************************************* 12687 ** CUSTOM TOKENIZERS 12688 ** 12689 ** Applications may also register custom tokenizer types. A tokenizer 12690 ** is registered by providing fts5 with a populated instance of the 12691 ** following structure. All structure methods must be defined, setting 12692 ** any member of the fts5_tokenizer struct to NULL leads to undefined 12693 ** behaviour. The structure methods are expected to function as follows: 12694 ** 12695 ** xCreate: 12696 ** This function is used to allocate and initialize a tokenizer instance. 12697 ** A tokenizer instance is required to actually tokenize text. 12698 ** 12699 ** The first argument passed to this function is a copy of the (void*) 12700 ** pointer provided by the application when the fts5_tokenizer object 12701 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 12702 ** The second and third arguments are an array of nul-terminated strings 12703 ** containing the tokenizer arguments, if any, specified following the 12704 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12705 ** to create the FTS5 table. 12706 ** 12707 ** The final argument is an output variable. If successful, (*ppOut) 12708 ** should be set to point to the new tokenizer handle and SQLITE_OK 12709 ** returned. If an error occurs, some value other than SQLITE_OK should 12710 ** be returned. In this case, fts5 assumes that the final value of *ppOut 12711 ** is undefined. 12712 ** 12713 ** xDelete: 12714 ** This function is invoked to delete a tokenizer handle previously 12715 ** allocated using xCreate(). Fts5 guarantees that this function will 12716 ** be invoked exactly once for each successful call to xCreate(). 12717 ** 12718 ** xTokenize: 12719 ** This function is expected to tokenize the nText byte string indicated 12720 ** by argument pText. pText may or may not be nul-terminated. The first 12721 ** argument passed to this function is a pointer to an Fts5Tokenizer object 12722 ** returned by an earlier call to xCreate(). 12723 ** 12724 ** The second argument indicates the reason that FTS5 is requesting 12725 ** tokenization of the supplied text. This is always one of the following 12726 ** four values: 12727 ** 12728 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12729 ** or removed from the FTS table. The tokenizer is being invoked to 12730 ** determine the set of tokens to add to (or delete from) the 12731 ** FTS index. 12732 ** 12733 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12734 ** against the FTS index. The tokenizer is being called to tokenize 12735 ** a bareword or quoted string specified as part of the query. 12736 ** 12737 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12738 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12739 ** followed by a "*" character, indicating that the last token 12740 ** returned by the tokenizer will be treated as a token prefix. 12741 ** 12742 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12743 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 12744 ** function. Or an fts5_api.xColumnSize() request made by the same 12745 ** on a columnsize=0 database. 12746 ** </ul> 12747 ** 12748 ** For each token in the input string, the supplied callback xToken() must 12749 ** be invoked. The first argument to it should be a copy of the pointer 12750 ** passed as the second argument to xTokenize(). The third and fourth 12751 ** arguments are a pointer to a buffer containing the token text, and the 12752 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12753 ** of the first byte of and first byte immediately following the text from 12754 ** which the token is derived within the input. 12755 ** 12756 ** The second argument passed to the xToken() callback ("tflags") should 12757 ** normally be set to 0. The exception is if the tokenizer supports 12758 ** synonyms. In this case see the discussion below for details. 12759 ** 12760 ** FTS5 assumes the xToken() callback is invoked for each token in the 12761 ** order that they occur within the input text. 12762 ** 12763 ** If an xToken() callback returns any value other than SQLITE_OK, then 12764 ** the tokenization should be abandoned and the xTokenize() method should 12765 ** immediately return a copy of the xToken() return value. Or, if the 12766 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12767 ** if an error occurs with the xTokenize() implementation itself, it 12768 ** may abandon the tokenization and return any error code other than 12769 ** SQLITE_OK or SQLITE_DONE. 12770 ** 12771 ** SYNONYM SUPPORT 12772 ** 12773 ** Custom tokenizers may also support synonyms. Consider a case in which a 12774 ** user wishes to query for a phrase such as "first place". Using the 12775 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 12776 ** of "first place" within the document set, but not alternative forms 12777 ** such as "1st place". In some applications, it would be better to match 12778 ** all instances of "first place" or "1st place" regardless of which form 12779 ** the user specified in the MATCH query text. 12780 ** 12781 ** There are several ways to approach this in FTS5: 12782 ** 12783 ** <ol><li> By mapping all synonyms to a single token. In this case, using 12784 ** the above example, this means that the tokenizer returns the 12785 ** same token for inputs "first" and "1st". Say that token is in 12786 ** fact "first", so that when the user inserts the document "I won 12787 ** 1st place" entries are added to the index for tokens "i", "won", 12788 ** "first" and "place". If the user then queries for '1st + place', 12789 ** the tokenizer substitutes "first" for "1st" and the query works 12790 ** as expected. 12791 ** 12792 ** <li> By querying the index for all synonyms of each query term 12793 ** separately. In this case, when tokenizing query text, the 12794 ** tokenizer may provide multiple synonyms for a single term 12795 ** within the document. FTS5 then queries the index for each 12796 ** synonym individually. For example, faced with the query: 12797 ** 12798 ** <codeblock> 12799 ** ... MATCH 'first place'</codeblock> 12800 ** 12801 ** the tokenizer offers both "1st" and "first" as synonyms for the 12802 ** first token in the MATCH query and FTS5 effectively runs a query 12803 ** similar to: 12804 ** 12805 ** <codeblock> 12806 ** ... MATCH '(first OR 1st) place'</codeblock> 12807 ** 12808 ** except that, for the purposes of auxiliary functions, the query 12809 ** still appears to contain just two phrases - "(first OR 1st)" 12810 ** being treated as a single phrase. 12811 ** 12812 ** <li> By adding multiple synonyms for a single term to the FTS index. 12813 ** Using this method, when tokenizing document text, the tokenizer 12814 ** provides multiple synonyms for each token. So that when a 12815 ** document such as "I won first place" is tokenized, entries are 12816 ** added to the FTS index for "i", "won", "first", "1st" and 12817 ** "place". 12818 ** 12819 ** This way, even if the tokenizer does not provide synonyms 12820 ** when tokenizing query text (it should not - to do so would be 12821 ** inefficient), it doesn't matter if the user queries for 12822 ** 'first + place' or '1st + place', as there are entries in the 12823 ** FTS index corresponding to both forms of the first token. 12824 ** </ol> 12825 ** 12826 ** Whether it is parsing document or query text, any call to xToken that 12827 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12828 ** is considered to supply a synonym for the previous token. For example, 12829 ** when parsing the document "I won first place", a tokenizer that supports 12830 ** synonyms would call xToken() 5 times, as follows: 12831 ** 12832 ** <codeblock> 12833 ** xToken(pCtx, 0, "i", 1, 0, 1); 12834 ** xToken(pCtx, 0, "won", 3, 2, 5); 12835 ** xToken(pCtx, 0, "first", 5, 6, 11); 12836 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12837 ** xToken(pCtx, 0, "place", 5, 12, 17); 12838 **</codeblock> 12839 ** 12840 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12841 ** xToken() is called. Multiple synonyms may be specified for a single token 12842 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12843 ** There is no limit to the number of synonyms that may be provided for a 12844 ** single token. 12845 ** 12846 ** In many cases, method (1) above is the best approach. It does not add 12847 ** extra data to the FTS index or require FTS5 to query for multiple terms, 12848 ** so it is efficient in terms of disk space and query speed. However, it 12849 ** does not support prefix queries very well. If, as suggested above, the 12850 ** token "first" is substituted for "1st" by the tokenizer, then the query: 12851 ** 12852 ** <codeblock> 12853 ** ... MATCH '1s*'</codeblock> 12854 ** 12855 ** will not match documents that contain the token "1st" (as the tokenizer 12856 ** will probably not map "1s" to any prefix of "first"). 12857 ** 12858 ** For full prefix support, method (3) may be preferred. In this case, 12859 ** because the index contains entries for both "first" and "1st", prefix 12860 ** queries such as 'fi*' or '1s*' will match correctly. However, because 12861 ** extra entries are added to the FTS index, this method uses more space 12862 ** within the database. 12863 ** 12864 ** Method (2) offers a midpoint between (1) and (3). Using this method, 12865 ** a query such as '1s*' will match documents that contain the literal 12866 ** token "1st", but not "first" (assuming the tokenizer is not able to 12867 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 12868 ** will match against "1st" and "first". This method does not require 12869 ** extra disk space, as no extra entries are added to the FTS index. 12870 ** On the other hand, it may require more CPU cycles to run MATCH queries, 12871 ** as separate queries of the FTS index are required for each synonym. 12872 ** 12873 ** When using methods (2) or (3), it is important that the tokenizer only 12874 ** provide synonyms when tokenizing document text (method (2)) or query 12875 ** text (method (3)), not both. Doing so will not cause any errors, but is 12876 ** inefficient. 12877 */ 12878 typedef struct Fts5Tokenizer Fts5Tokenizer; 12879 typedef struct fts5_tokenizer fts5_tokenizer; 12880 struct fts5_tokenizer { 12881 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12882 void (*xDelete)(Fts5Tokenizer*); 12883 int (*xTokenize)(Fts5Tokenizer*, 12884 void *pCtx, 12885 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12886 const char *pText, int nText, 12887 int (*xToken)( 12888 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12889 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12890 const char *pToken, /* Pointer to buffer containing token */ 12891 int nToken, /* Size of token in bytes */ 12892 int iStart, /* Byte offset of token within input text */ 12893 int iEnd /* Byte offset of end of token within input text */ 12894 ) 12895 ); 12896 }; 12897 12898 /* Flags that may be passed as the third argument to xTokenize() */ 12899 #define FTS5_TOKENIZE_QUERY 0x0001 12900 #define FTS5_TOKENIZE_PREFIX 0x0002 12901 #define FTS5_TOKENIZE_DOCUMENT 0x0004 12902 #define FTS5_TOKENIZE_AUX 0x0008 12903 12904 /* Flags that may be passed by the tokenizer implementation back to FTS5 12905 ** as the third argument to the supplied xToken callback. */ 12906 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12907 12908 /* 12909 ** END OF CUSTOM TOKENIZERS 12910 *************************************************************************/ 12911 12912 /************************************************************************* 12913 ** FTS5 EXTENSION REGISTRATION API 12914 */ 12915 typedef struct fts5_api fts5_api; 12916 struct fts5_api { 12917 int iVersion; /* Currently always set to 2 */ 12918 12919 /* Create a new tokenizer */ 12920 int (*xCreateTokenizer)( 12921 fts5_api *pApi, 12922 const char *zName, 12923 void *pContext, 12924 fts5_tokenizer *pTokenizer, 12925 void (*xDestroy)(void*) 12926 ); 12927 12928 /* Find an existing tokenizer */ 12929 int (*xFindTokenizer)( 12930 fts5_api *pApi, 12931 const char *zName, 12932 void **ppContext, 12933 fts5_tokenizer *pTokenizer 12934 ); 12935 12936 /* Create a new auxiliary function */ 12937 int (*xCreateFunction)( 12938 fts5_api *pApi, 12939 const char *zName, 12940 void *pContext, 12941 fts5_extension_function xFunction, 12942 void (*xDestroy)(void*) 12943 ); 12944 }; 12945 12946 /* 12947 ** END OF REGISTRATION API 12948 *************************************************************************/ 12949 12950 #ifdef __cplusplus 12951 } /* end of the 'extern "C"' block */ 12952 #endif 12953 12954 #endif /* _FTS5_H */ 12955 12956 /******** End of fts5.h *********/ 12957