1 /*
2 ** 2001 September 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 file contains C code routines that are called by the parser
13 ** to handle INSERT statements in SQLite.
14 */
15 #include "sqliteInt.h"
16
17 /*
18 ** Generate code that will open a table for reading.
19 */
sqlite3OpenTable(Parse * p,int iCur,int iDb,Table * pTab,int opcode)20 void sqlite3OpenTable(
21 Parse *p, /* Generate code into this VDBE */
22 int iCur, /* The cursor number of the table */
23 int iDb, /* The database index in sqlite3.aDb[] */
24 Table *pTab, /* The table to be opened */
25 int opcode /* OP_OpenRead or OP_OpenWrite */
26 ){
27 Vdbe *v;
28 if( IsVirtual(pTab) ) return;
29 v = sqlite3GetVdbe(p);
30 assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
31 sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite)?1:0, pTab->zName);
32 sqlite3VdbeAddOp3(v, opcode, iCur, pTab->tnum, iDb);
33 sqlite3VdbeChangeP4(v, -1, SQLITE_INT_TO_PTR(pTab->nCol), P4_INT32);
34 VdbeComment((v, "%s", pTab->zName));
35 }
36
37 /*
38 ** Return a pointer to the column affinity string associated with index
39 ** pIdx. A column affinity string has one character for each column in
40 ** the table, according to the affinity of the column:
41 **
42 ** Character Column affinity
43 ** ------------------------------
44 ** 'a' TEXT
45 ** 'b' NONE
46 ** 'c' NUMERIC
47 ** 'd' INTEGER
48 ** 'e' REAL
49 **
50 ** An extra 'b' is appended to the end of the string to cover the
51 ** rowid that appears as the last column in every index.
52 **
53 ** Memory for the buffer containing the column index affinity string
54 ** is managed along with the rest of the Index structure. It will be
55 ** released when sqlite3DeleteIndex() is called.
56 */
sqlite3IndexAffinityStr(Vdbe * v,Index * pIdx)57 const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
58 if( !pIdx->zColAff ){
59 /* The first time a column affinity string for a particular index is
60 ** required, it is allocated and populated here. It is then stored as
61 ** a member of the Index structure for subsequent use.
62 **
63 ** The column affinity string will eventually be deleted by
64 ** sqliteDeleteIndex() when the Index structure itself is cleaned
65 ** up.
66 */
67 int n;
68 Table *pTab = pIdx->pTable;
69 sqlite3 *db = sqlite3VdbeDb(v);
70 pIdx->zColAff = (char *)sqlite3DbMallocRaw(0, pIdx->nColumn+2);
71 if( !pIdx->zColAff ){
72 db->mallocFailed = 1;
73 return 0;
74 }
75 for(n=0; n<pIdx->nColumn; n++){
76 pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
77 }
78 pIdx->zColAff[n++] = SQLITE_AFF_NONE;
79 pIdx->zColAff[n] = 0;
80 }
81
82 return pIdx->zColAff;
83 }
84
85 /*
86 ** Set P4 of the most recently inserted opcode to a column affinity
87 ** string for table pTab. A column affinity string has one character
88 ** for each column indexed by the index, according to the affinity of the
89 ** column:
90 **
91 ** Character Column affinity
92 ** ------------------------------
93 ** 'a' TEXT
94 ** 'b' NONE
95 ** 'c' NUMERIC
96 ** 'd' INTEGER
97 ** 'e' REAL
98 */
sqlite3TableAffinityStr(Vdbe * v,Table * pTab)99 void sqlite3TableAffinityStr(Vdbe *v, Table *pTab){
100 /* The first time a column affinity string for a particular table
101 ** is required, it is allocated and populated here. It is then
102 ** stored as a member of the Table structure for subsequent use.
103 **
104 ** The column affinity string will eventually be deleted by
105 ** sqlite3DeleteTable() when the Table structure itself is cleaned up.
106 */
107 if( !pTab->zColAff ){
108 char *zColAff;
109 int i;
110 sqlite3 *db = sqlite3VdbeDb(v);
111
112 zColAff = (char *)sqlite3DbMallocRaw(0, pTab->nCol+1);
113 if( !zColAff ){
114 db->mallocFailed = 1;
115 return;
116 }
117
118 for(i=0; i<pTab->nCol; i++){
119 zColAff[i] = pTab->aCol[i].affinity;
120 }
121 zColAff[pTab->nCol] = '\0';
122
123 pTab->zColAff = zColAff;
124 }
125
126 sqlite3VdbeChangeP4(v, -1, pTab->zColAff, P4_TRANSIENT);
127 }
128
129 /*
130 ** Return non-zero if the table pTab in database iDb or any of its indices
131 ** have been opened at any point in the VDBE program beginning at location
132 ** iStartAddr throught the end of the program. This is used to see if
133 ** a statement of the form "INSERT INTO <iDb, pTab> SELECT ..." can
134 ** run without using temporary table for the results of the SELECT.
135 */
readsTable(Parse * p,int iStartAddr,int iDb,Table * pTab)136 static int readsTable(Parse *p, int iStartAddr, int iDb, Table *pTab){
137 Vdbe *v = sqlite3GetVdbe(p);
138 int i;
139 int iEnd = sqlite3VdbeCurrentAddr(v);
140 #ifndef SQLITE_OMIT_VIRTUALTABLE
141 VTable *pVTab = IsVirtual(pTab) ? sqlite3GetVTable(p->db, pTab) : 0;
142 #endif
143
144 for(i=iStartAddr; i<iEnd; i++){
145 VdbeOp *pOp = sqlite3VdbeGetOp(v, i);
146 assert( pOp!=0 );
147 if( pOp->opcode==OP_OpenRead && pOp->p3==iDb ){
148 Index *pIndex;
149 int tnum = pOp->p2;
150 if( tnum==pTab->tnum ){
151 return 1;
152 }
153 for(pIndex=pTab->pIndex; pIndex; pIndex=pIndex->pNext){
154 if( tnum==pIndex->tnum ){
155 return 1;
156 }
157 }
158 }
159 #ifndef SQLITE_OMIT_VIRTUALTABLE
160 if( pOp->opcode==OP_VOpen && pOp->p4.pVtab==pVTab ){
161 assert( pOp->p4.pVtab!=0 );
162 assert( pOp->p4type==P4_VTAB );
163 return 1;
164 }
165 #endif
166 }
167 return 0;
168 }
169
170 #ifndef SQLITE_OMIT_AUTOINCREMENT
171 /*
172 ** Locate or create an AutoincInfo structure associated with table pTab
173 ** which is in database iDb. Return the register number for the register
174 ** that holds the maximum rowid.
175 **
176 ** There is at most one AutoincInfo structure per table even if the
177 ** same table is autoincremented multiple times due to inserts within
178 ** triggers. A new AutoincInfo structure is created if this is the
179 ** first use of table pTab. On 2nd and subsequent uses, the original
180 ** AutoincInfo structure is used.
181 **
182 ** Three memory locations are allocated:
183 **
184 ** (1) Register to hold the name of the pTab table.
185 ** (2) Register to hold the maximum ROWID of pTab.
186 ** (3) Register to hold the rowid in sqlite_sequence of pTab
187 **
188 ** The 2nd register is the one that is returned. That is all the
189 ** insert routine needs to know about.
190 */
autoIncBegin(Parse * pParse,int iDb,Table * pTab)191 static int autoIncBegin(
192 Parse *pParse, /* Parsing context */
193 int iDb, /* Index of the database holding pTab */
194 Table *pTab /* The table we are writing to */
195 ){
196 int memId = 0; /* Register holding maximum rowid */
197 if( pTab->tabFlags & TF_Autoincrement ){
198 Parse *pToplevel = sqlite3ParseToplevel(pParse);
199 AutoincInfo *pInfo;
200
201 pInfo = pToplevel->pAinc;
202 while( pInfo && pInfo->pTab!=pTab ){ pInfo = pInfo->pNext; }
203 if( pInfo==0 ){
204 pInfo = sqlite3DbMallocRaw(pParse->db, sizeof(*pInfo));
205 if( pInfo==0 ) return 0;
206 pInfo->pNext = pToplevel->pAinc;
207 pToplevel->pAinc = pInfo;
208 pInfo->pTab = pTab;
209 pInfo->iDb = iDb;
210 pToplevel->nMem++; /* Register to hold name of table */
211 pInfo->regCtr = ++pToplevel->nMem; /* Max rowid register */
212 pToplevel->nMem++; /* Rowid in sqlite_sequence */
213 }
214 memId = pInfo->regCtr;
215 }
216 return memId;
217 }
218
219 /*
220 ** This routine generates code that will initialize all of the
221 ** register used by the autoincrement tracker.
222 */
sqlite3AutoincrementBegin(Parse * pParse)223 void sqlite3AutoincrementBegin(Parse *pParse){
224 AutoincInfo *p; /* Information about an AUTOINCREMENT */
225 sqlite3 *db = pParse->db; /* The database connection */
226 Db *pDb; /* Database only autoinc table */
227 int memId; /* Register holding max rowid */
228 int addr; /* A VDBE address */
229 Vdbe *v = pParse->pVdbe; /* VDBE under construction */
230
231 /* This routine is never called during trigger-generation. It is
232 ** only called from the top-level */
233 assert( pParse->pTriggerTab==0 );
234 assert( pParse==sqlite3ParseToplevel(pParse) );
235
236 assert( v ); /* We failed long ago if this is not so */
237 for(p = pParse->pAinc; p; p = p->pNext){
238 pDb = &db->aDb[p->iDb];
239 memId = p->regCtr;
240 assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
241 sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
242 addr = sqlite3VdbeCurrentAddr(v);
243 sqlite3VdbeAddOp4(v, OP_String8, 0, memId-1, 0, p->pTab->zName, 0);
244 sqlite3VdbeAddOp2(v, OP_Rewind, 0, addr+9);
245 sqlite3VdbeAddOp3(v, OP_Column, 0, 0, memId);
246 sqlite3VdbeAddOp3(v, OP_Ne, memId-1, addr+7, memId);
247 sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
248 sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
249 sqlite3VdbeAddOp3(v, OP_Column, 0, 1, memId);
250 sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+9);
251 sqlite3VdbeAddOp2(v, OP_Next, 0, addr+2);
252 sqlite3VdbeAddOp2(v, OP_Integer, 0, memId);
253 sqlite3VdbeAddOp0(v, OP_Close);
254 }
255 }
256
257 /*
258 ** Update the maximum rowid for an autoincrement calculation.
259 **
260 ** This routine should be called when the top of the stack holds a
261 ** new rowid that is about to be inserted. If that new rowid is
262 ** larger than the maximum rowid in the memId memory cell, then the
263 ** memory cell is updated. The stack is unchanged.
264 */
autoIncStep(Parse * pParse,int memId,int regRowid)265 static void autoIncStep(Parse *pParse, int memId, int regRowid){
266 if( memId>0 ){
267 sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, regRowid);
268 }
269 }
270
271 /*
272 ** This routine generates the code needed to write autoincrement
273 ** maximum rowid values back into the sqlite_sequence register.
274 ** Every statement that might do an INSERT into an autoincrement
275 ** table (either directly or through triggers) needs to call this
276 ** routine just before the "exit" code.
277 */
sqlite3AutoincrementEnd(Parse * pParse)278 void sqlite3AutoincrementEnd(Parse *pParse){
279 AutoincInfo *p;
280 Vdbe *v = pParse->pVdbe;
281 sqlite3 *db = pParse->db;
282
283 assert( v );
284 for(p = pParse->pAinc; p; p = p->pNext){
285 Db *pDb = &db->aDb[p->iDb];
286 int j1, j2, j3, j4, j5;
287 int iRec;
288 int memId = p->regCtr;
289
290 iRec = sqlite3GetTempReg(pParse);
291 assert( sqlite3SchemaMutexHeld(db, 0, pDb->pSchema) );
292 sqlite3OpenTable(pParse, 0, p->iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
293 j1 = sqlite3VdbeAddOp1(v, OP_NotNull, memId+1);
294 j2 = sqlite3VdbeAddOp0(v, OP_Rewind);
295 j3 = sqlite3VdbeAddOp3(v, OP_Column, 0, 0, iRec);
296 j4 = sqlite3VdbeAddOp3(v, OP_Eq, memId-1, 0, iRec);
297 sqlite3VdbeAddOp2(v, OP_Next, 0, j3);
298 sqlite3VdbeJumpHere(v, j2);
299 sqlite3VdbeAddOp2(v, OP_NewRowid, 0, memId+1);
300 j5 = sqlite3VdbeAddOp0(v, OP_Goto);
301 sqlite3VdbeJumpHere(v, j4);
302 sqlite3VdbeAddOp2(v, OP_Rowid, 0, memId+1);
303 sqlite3VdbeJumpHere(v, j1);
304 sqlite3VdbeJumpHere(v, j5);
305 sqlite3VdbeAddOp3(v, OP_MakeRecord, memId-1, 2, iRec);
306 sqlite3VdbeAddOp3(v, OP_Insert, 0, iRec, memId+1);
307 sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
308 sqlite3VdbeAddOp0(v, OP_Close);
309 sqlite3ReleaseTempReg(pParse, iRec);
310 }
311 }
312 #else
313 /*
314 ** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
315 ** above are all no-ops
316 */
317 # define autoIncBegin(A,B,C) (0)
318 # define autoIncStep(A,B,C)
319 #endif /* SQLITE_OMIT_AUTOINCREMENT */
320
321
322 /* Forward declaration */
323 static int xferOptimization(
324 Parse *pParse, /* Parser context */
325 Table *pDest, /* The table we are inserting into */
326 Select *pSelect, /* A SELECT statement to use as the data source */
327 int onError, /* How to handle constraint errors */
328 int iDbDest /* The database of pDest */
329 );
330
331 /*
332 ** This routine is call to handle SQL of the following forms:
333 **
334 ** insert into TABLE (IDLIST) values(EXPRLIST)
335 ** insert into TABLE (IDLIST) select
336 **
337 ** The IDLIST following the table name is always optional. If omitted,
338 ** then a list of all columns for the table is substituted. The IDLIST
339 ** appears in the pColumn parameter. pColumn is NULL if IDLIST is omitted.
340 **
341 ** The pList parameter holds EXPRLIST in the first form of the INSERT
342 ** statement above, and pSelect is NULL. For the second form, pList is
343 ** NULL and pSelect is a pointer to the select statement used to generate
344 ** data for the insert.
345 **
346 ** The code generated follows one of four templates. For a simple
347 ** select with data coming from a VALUES clause, the code executes
348 ** once straight down through. Pseudo-code follows (we call this
349 ** the "1st template"):
350 **
351 ** open write cursor to <table> and its indices
352 ** puts VALUES clause expressions onto the stack
353 ** write the resulting record into <table>
354 ** cleanup
355 **
356 ** The three remaining templates assume the statement is of the form
357 **
358 ** INSERT INTO <table> SELECT ...
359 **
360 ** If the SELECT clause is of the restricted form "SELECT * FROM <table2>" -
361 ** in other words if the SELECT pulls all columns from a single table
362 ** and there is no WHERE or LIMIT or GROUP BY or ORDER BY clauses, and
363 ** if <table2> and <table1> are distinct tables but have identical
364 ** schemas, including all the same indices, then a special optimization
365 ** is invoked that copies raw records from <table2> over to <table1>.
366 ** See the xferOptimization() function for the implementation of this
367 ** template. This is the 2nd template.
368 **
369 ** open a write cursor to <table>
370 ** open read cursor on <table2>
371 ** transfer all records in <table2> over to <table>
372 ** close cursors
373 ** foreach index on <table>
374 ** open a write cursor on the <table> index
375 ** open a read cursor on the corresponding <table2> index
376 ** transfer all records from the read to the write cursors
377 ** close cursors
378 ** end foreach
379 **
380 ** The 3rd template is for when the second template does not apply
381 ** and the SELECT clause does not read from <table> at any time.
382 ** The generated code follows this template:
383 **
384 ** EOF <- 0
385 ** X <- A
386 ** goto B
387 ** A: setup for the SELECT
388 ** loop over the rows in the SELECT
389 ** load values into registers R..R+n
390 ** yield X
391 ** end loop
392 ** cleanup after the SELECT
393 ** EOF <- 1
394 ** yield X
395 ** goto A
396 ** B: open write cursor to <table> and its indices
397 ** C: yield X
398 ** if EOF goto D
399 ** insert the select result into <table> from R..R+n
400 ** goto C
401 ** D: cleanup
402 **
403 ** The 4th template is used if the insert statement takes its
404 ** values from a SELECT but the data is being inserted into a table
405 ** that is also read as part of the SELECT. In the third form,
406 ** we have to use a intermediate table to store the results of
407 ** the select. The template is like this:
408 **
409 ** EOF <- 0
410 ** X <- A
411 ** goto B
412 ** A: setup for the SELECT
413 ** loop over the tables in the SELECT
414 ** load value into register R..R+n
415 ** yield X
416 ** end loop
417 ** cleanup after the SELECT
418 ** EOF <- 1
419 ** yield X
420 ** halt-error
421 ** B: open temp table
422 ** L: yield X
423 ** if EOF goto M
424 ** insert row from R..R+n into temp table
425 ** goto L
426 ** M: open write cursor to <table> and its indices
427 ** rewind temp table
428 ** C: loop over rows of intermediate table
429 ** transfer values form intermediate table into <table>
430 ** end loop
431 ** D: cleanup
432 */
sqlite3Insert(Parse * pParse,SrcList * pTabList,ExprList * pList,Select * pSelect,IdList * pColumn,int onError)433 void sqlite3Insert(
434 Parse *pParse, /* Parser context */
435 SrcList *pTabList, /* Name of table into which we are inserting */
436 ExprList *pList, /* List of values to be inserted */
437 Select *pSelect, /* A SELECT statement to use as the data source */
438 IdList *pColumn, /* Column names corresponding to IDLIST. */
439 int onError /* How to handle constraint errors */
440 ){
441 sqlite3 *db; /* The main database structure */
442 Table *pTab; /* The table to insert into. aka TABLE */
443 char *zTab; /* Name of the table into which we are inserting */
444 const char *zDb; /* Name of the database holding this table */
445 int i, j, idx; /* Loop counters */
446 Vdbe *v; /* Generate code into this virtual machine */
447 Index *pIdx; /* For looping over indices of the table */
448 int nColumn; /* Number of columns in the data */
449 int nHidden = 0; /* Number of hidden columns if TABLE is virtual */
450 int baseCur = 0; /* VDBE Cursor number for pTab */
451 int keyColumn = -1; /* Column that is the INTEGER PRIMARY KEY */
452 int endOfLoop; /* Label for the end of the insertion loop */
453 int useTempTable = 0; /* Store SELECT results in intermediate table */
454 int srcTab = 0; /* Data comes from this temporary cursor if >=0 */
455 int addrInsTop = 0; /* Jump to label "D" */
456 int addrCont = 0; /* Top of insert loop. Label "C" in templates 3 and 4 */
457 int addrSelect = 0; /* Address of coroutine that implements the SELECT */
458 SelectDest dest; /* Destination for SELECT on rhs of INSERT */
459 int iDb; /* Index of database holding TABLE */
460 Db *pDb; /* The database containing table being inserted into */
461 int appendFlag = 0; /* True if the insert is likely to be an append */
462
463 /* Register allocations */
464 int regFromSelect = 0;/* Base register for data coming from SELECT */
465 int regAutoinc = 0; /* Register holding the AUTOINCREMENT counter */
466 int regRowCount = 0; /* Memory cell used for the row counter */
467 int regIns; /* Block of regs holding rowid+data being inserted */
468 int regRowid; /* registers holding insert rowid */
469 int regData; /* register holding first column to insert */
470 int regEof = 0; /* Register recording end of SELECT data */
471 int *aRegIdx = 0; /* One register allocated to each index */
472
473 #ifndef SQLITE_OMIT_TRIGGER
474 int isView; /* True if attempting to insert into a view */
475 Trigger *pTrigger; /* List of triggers on pTab, if required */
476 int tmask; /* Mask of trigger times */
477 #endif
478
479 db = pParse->db;
480 memset(&dest, 0, sizeof(dest));
481 if( pParse->nErr || db->mallocFailed ){
482 goto insert_cleanup;
483 }
484
485 /* Locate the table into which we will be inserting new information.
486 */
487 assert( pTabList->nSrc==1 );
488 zTab = pTabList->a[0].zName;
489 if( NEVER(zTab==0) ) goto insert_cleanup;
490 pTab = sqlite3SrcListLookup(pParse, pTabList);
491 if( pTab==0 ){
492 goto insert_cleanup;
493 }
494 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
495 assert( iDb<db->nDb );
496 pDb = &db->aDb[iDb];
497 zDb = pDb->zName;
498 if( sqlite3AuthCheck(pParse, SQLITE_INSERT, pTab->zName, 0, zDb) ){
499 goto insert_cleanup;
500 }
501
502 /* Figure out if we have any triggers and if the table being
503 ** inserted into is a view
504 */
505 #ifndef SQLITE_OMIT_TRIGGER
506 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_INSERT, 0, &tmask);
507 isView = pTab->pSelect!=0;
508 #else
509 # define pTrigger 0
510 # define tmask 0
511 # define isView 0
512 #endif
513 #ifdef SQLITE_OMIT_VIEW
514 # undef isView
515 # define isView 0
516 #endif
517 assert( (pTrigger && tmask) || (pTrigger==0 && tmask==0) );
518
519 /* If pTab is really a view, make sure it has been initialized.
520 ** ViewGetColumnNames() is a no-op if pTab is not a view (or virtual
521 ** module table).
522 */
523 if( sqlite3ViewGetColumnNames(pParse, pTab) ){
524 goto insert_cleanup;
525 }
526
527 /* Ensure that:
528 * (a) the table is not read-only,
529 * (b) that if it is a view then ON INSERT triggers exist
530 */
531 if( sqlite3IsReadOnly(pParse, pTab, tmask) ){
532 goto insert_cleanup;
533 }
534
535 /* Allocate a VDBE
536 */
537 v = sqlite3GetVdbe(pParse);
538 if( v==0 ) goto insert_cleanup;
539 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
540 sqlite3BeginWriteOperation(pParse, pSelect || pTrigger, iDb);
541
542 #ifndef SQLITE_OMIT_XFER_OPT
543 /* If the statement is of the form
544 **
545 ** INSERT INTO <table1> SELECT * FROM <table2>;
546 **
547 ** Then special optimizations can be applied that make the transfer
548 ** very fast and which reduce fragmentation of indices.
549 **
550 ** This is the 2nd template.
551 */
552 if( pColumn==0 && xferOptimization(pParse, pTab, pSelect, onError, iDb) ){
553 assert( !pTrigger );
554 assert( pList==0 );
555 goto insert_end;
556 }
557 #endif /* SQLITE_OMIT_XFER_OPT */
558
559 /* If this is an AUTOINCREMENT table, look up the sequence number in the
560 ** sqlite_sequence table and store it in memory cell regAutoinc.
561 */
562 regAutoinc = autoIncBegin(pParse, iDb, pTab);
563
564 /* Figure out how many columns of data are supplied. If the data
565 ** is coming from a SELECT statement, then generate a co-routine that
566 ** produces a single row of the SELECT on each invocation. The
567 ** co-routine is the common header to the 3rd and 4th templates.
568 */
569 if( pSelect ){
570 /* Data is coming from a SELECT. Generate code to implement that SELECT
571 ** as a co-routine. The code is common to both the 3rd and 4th
572 ** templates:
573 **
574 ** EOF <- 0
575 ** X <- A
576 ** goto B
577 ** A: setup for the SELECT
578 ** loop over the tables in the SELECT
579 ** load value into register R..R+n
580 ** yield X
581 ** end loop
582 ** cleanup after the SELECT
583 ** EOF <- 1
584 ** yield X
585 ** halt-error
586 **
587 ** On each invocation of the co-routine, it puts a single row of the
588 ** SELECT result into registers dest.iMem...dest.iMem+dest.nMem-1.
589 ** (These output registers are allocated by sqlite3Select().) When
590 ** the SELECT completes, it sets the EOF flag stored in regEof.
591 */
592 int rc, j1;
593
594 regEof = ++pParse->nMem;
595 sqlite3VdbeAddOp2(v, OP_Integer, 0, regEof); /* EOF <- 0 */
596 VdbeComment((v, "SELECT eof flag"));
597 sqlite3SelectDestInit(&dest, SRT_Coroutine, ++pParse->nMem);
598 addrSelect = sqlite3VdbeCurrentAddr(v)+2;
599 sqlite3VdbeAddOp2(v, OP_Integer, addrSelect-1, dest.iParm);
600 j1 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
601 VdbeComment((v, "Jump over SELECT coroutine"));
602
603 /* Resolve the expressions in the SELECT statement and execute it. */
604 rc = sqlite3Select(pParse, pSelect, &dest);
605 assert( pParse->nErr==0 || rc );
606 if( rc || NEVER(pParse->nErr) || db->mallocFailed ){
607 goto insert_cleanup;
608 }
609 sqlite3VdbeAddOp2(v, OP_Integer, 1, regEof); /* EOF <- 1 */
610 sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm); /* yield X */
611 sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_INTERNAL, OE_Abort);
612 VdbeComment((v, "End of SELECT coroutine"));
613 sqlite3VdbeJumpHere(v, j1); /* label B: */
614
615 regFromSelect = dest.iMem;
616 assert( pSelect->pEList );
617 nColumn = pSelect->pEList->nExpr;
618 assert( dest.nMem==nColumn );
619
620 /* Set useTempTable to TRUE if the result of the SELECT statement
621 ** should be written into a temporary table (template 4). Set to
622 ** FALSE if each* row of the SELECT can be written directly into
623 ** the destination table (template 3).
624 **
625 ** A temp table must be used if the table being updated is also one
626 ** of the tables being read by the SELECT statement. Also use a
627 ** temp table in the case of row triggers.
628 */
629 if( pTrigger || readsTable(pParse, addrSelect, iDb, pTab) ){
630 useTempTable = 1;
631 }
632
633 if( useTempTable ){
634 /* Invoke the coroutine to extract information from the SELECT
635 ** and add it to a transient table srcTab. The code generated
636 ** here is from the 4th template:
637 **
638 ** B: open temp table
639 ** L: yield X
640 ** if EOF goto M
641 ** insert row from R..R+n into temp table
642 ** goto L
643 ** M: ...
644 */
645 int regRec; /* Register to hold packed record */
646 int regTempRowid; /* Register to hold temp table ROWID */
647 int addrTop; /* Label "L" */
648 int addrIf; /* Address of jump to M */
649
650 srcTab = pParse->nTab++;
651 regRec = sqlite3GetTempReg(pParse);
652 regTempRowid = sqlite3GetTempReg(pParse);
653 sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, nColumn);
654 addrTop = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
655 addrIf = sqlite3VdbeAddOp1(v, OP_If, regEof);
656 sqlite3VdbeAddOp3(v, OP_MakeRecord, regFromSelect, nColumn, regRec);
657 sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regTempRowid);
658 sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regTempRowid);
659 sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop);
660 sqlite3VdbeJumpHere(v, addrIf);
661 sqlite3ReleaseTempReg(pParse, regRec);
662 sqlite3ReleaseTempReg(pParse, regTempRowid);
663 }
664 }else{
665 /* This is the case if the data for the INSERT is coming from a VALUES
666 ** clause
667 */
668 NameContext sNC;
669 memset(&sNC, 0, sizeof(sNC));
670 sNC.pParse = pParse;
671 srcTab = -1;
672 assert( useTempTable==0 );
673 nColumn = pList ? pList->nExpr : 0;
674 for(i=0; i<nColumn; i++){
675 if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
676 goto insert_cleanup;
677 }
678 }
679 }
680
681 /* Make sure the number of columns in the source data matches the number
682 ** of columns to be inserted into the table.
683 */
684 if( IsVirtual(pTab) ){
685 for(i=0; i<pTab->nCol; i++){
686 nHidden += (IsHiddenColumn(&pTab->aCol[i]) ? 1 : 0);
687 }
688 }
689 if( pColumn==0 && nColumn && nColumn!=(pTab->nCol-nHidden) ){
690 sqlite3ErrorMsg(pParse,
691 "table %S has %d columns but %d values were supplied",
692 pTabList, 0, pTab->nCol-nHidden, nColumn);
693 goto insert_cleanup;
694 }
695 if( pColumn!=0 && nColumn!=pColumn->nId ){
696 sqlite3ErrorMsg(pParse, "%d values for %d columns", nColumn, pColumn->nId);
697 goto insert_cleanup;
698 }
699
700 /* If the INSERT statement included an IDLIST term, then make sure
701 ** all elements of the IDLIST really are columns of the table and
702 ** remember the column indices.
703 **
704 ** If the table has an INTEGER PRIMARY KEY column and that column
705 ** is named in the IDLIST, then record in the keyColumn variable
706 ** the index into IDLIST of the primary key column. keyColumn is
707 ** the index of the primary key as it appears in IDLIST, not as
708 ** is appears in the original table. (The index of the primary
709 ** key in the original table is pTab->iPKey.)
710 */
711 if( pColumn ){
712 for(i=0; i<pColumn->nId; i++){
713 pColumn->a[i].idx = -1;
714 }
715 for(i=0; i<pColumn->nId; i++){
716 for(j=0; j<pTab->nCol; j++){
717 if( sqlite3StrICmp(pColumn->a[i].zName, pTab->aCol[j].zName)==0 ){
718 pColumn->a[i].idx = j;
719 if( j==pTab->iPKey ){
720 keyColumn = i;
721 }
722 break;
723 }
724 }
725 if( j>=pTab->nCol ){
726 if( sqlite3IsRowid(pColumn->a[i].zName) ){
727 keyColumn = i;
728 }else{
729 sqlite3ErrorMsg(pParse, "table %S has no column named %s",
730 pTabList, 0, pColumn->a[i].zName);
731 pParse->checkSchema = 1;
732 goto insert_cleanup;
733 }
734 }
735 }
736 }
737
738 /* If there is no IDLIST term but the table has an integer primary
739 ** key, the set the keyColumn variable to the primary key column index
740 ** in the original table definition.
741 */
742 if( pColumn==0 && nColumn>0 ){
743 keyColumn = pTab->iPKey;
744 }
745
746 /* Initialize the count of rows to be inserted
747 */
748 if( db->flags & SQLITE_CountRows ){
749 regRowCount = ++pParse->nMem;
750 sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount);
751 }
752
753 /* If this is not a view, open the table and and all indices */
754 if( !isView ){
755 int nIdx;
756
757 baseCur = pParse->nTab;
758 nIdx = sqlite3OpenTableAndIndices(pParse, pTab, baseCur, OP_OpenWrite);
759 aRegIdx = sqlite3DbMallocRaw(db, sizeof(int)*(nIdx+1));
760 if( aRegIdx==0 ){
761 goto insert_cleanup;
762 }
763 for(i=0; i<nIdx; i++){
764 aRegIdx[i] = ++pParse->nMem;
765 }
766 }
767
768 /* This is the top of the main insertion loop */
769 if( useTempTable ){
770 /* This block codes the top of loop only. The complete loop is the
771 ** following pseudocode (template 4):
772 **
773 ** rewind temp table
774 ** C: loop over rows of intermediate table
775 ** transfer values form intermediate table into <table>
776 ** end loop
777 ** D: ...
778 */
779 addrInsTop = sqlite3VdbeAddOp1(v, OP_Rewind, srcTab);
780 addrCont = sqlite3VdbeCurrentAddr(v);
781 }else if( pSelect ){
782 /* This block codes the top of loop only. The complete loop is the
783 ** following pseudocode (template 3):
784 **
785 ** C: yield X
786 ** if EOF goto D
787 ** insert the select result into <table> from R..R+n
788 ** goto C
789 ** D: ...
790 */
791 addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iParm);
792 addrInsTop = sqlite3VdbeAddOp1(v, OP_If, regEof);
793 }
794
795 /* Allocate registers for holding the rowid of the new row,
796 ** the content of the new row, and the assemblied row record.
797 */
798 regRowid = regIns = pParse->nMem+1;
799 pParse->nMem += pTab->nCol + 1;
800 if( IsVirtual(pTab) ){
801 regRowid++;
802 pParse->nMem++;
803 }
804 regData = regRowid+1;
805
806 /* Run the BEFORE and INSTEAD OF triggers, if there are any
807 */
808 endOfLoop = sqlite3VdbeMakeLabel(v);
809 if( tmask & TRIGGER_BEFORE ){
810 int regCols = sqlite3GetTempRange(pParse, pTab->nCol+1);
811
812 /* build the NEW.* reference row. Note that if there is an INTEGER
813 ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
814 ** translated into a unique ID for the row. But on a BEFORE trigger,
815 ** we do not know what the unique ID will be (because the insert has
816 ** not happened yet) so we substitute a rowid of -1
817 */
818 if( keyColumn<0 ){
819 sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
820 }else{
821 int j1;
822 if( useTempTable ){
823 sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regCols);
824 }else{
825 assert( pSelect==0 ); /* Otherwise useTempTable is true */
826 sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regCols);
827 }
828 j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regCols);
829 sqlite3VdbeAddOp2(v, OP_Integer, -1, regCols);
830 sqlite3VdbeJumpHere(v, j1);
831 sqlite3VdbeAddOp1(v, OP_MustBeInt, regCols);
832 }
833
834 /* Cannot have triggers on a virtual table. If it were possible,
835 ** this block would have to account for hidden column.
836 */
837 assert( !IsVirtual(pTab) );
838
839 /* Create the new column data
840 */
841 for(i=0; i<pTab->nCol; i++){
842 if( pColumn==0 ){
843 j = i;
844 }else{
845 for(j=0; j<pColumn->nId; j++){
846 if( pColumn->a[j].idx==i ) break;
847 }
848 }
849 if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId) ){
850 sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);
851 }else if( useTempTable ){
852 sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1);
853 }else{
854 assert( pSelect==0 ); /* Otherwise useTempTable is true */
855 sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);
856 }
857 }
858
859 /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
860 ** do not attempt any conversions before assembling the record.
861 ** If this is a real table, attempt conversions as required by the
862 ** table column affinities.
863 */
864 if( !isView ){
865 sqlite3VdbeAddOp2(v, OP_Affinity, regCols+1, pTab->nCol);
866 sqlite3TableAffinityStr(v, pTab);
867 }
868
869 /* Fire BEFORE or INSTEAD OF triggers */
870 sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_BEFORE,
871 pTab, regCols-pTab->nCol-1, onError, endOfLoop);
872
873 sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
874 }
875
876 /* Push the record number for the new entry onto the stack. The
877 ** record number is a randomly generate integer created by NewRowid
878 ** except when the table has an INTEGER PRIMARY KEY column, in which
879 ** case the record number is the same as that column.
880 */
881 if( !isView ){
882 if( IsVirtual(pTab) ){
883 /* The row that the VUpdate opcode will delete: none */
884 sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
885 }
886 if( keyColumn>=0 ){
887 if( useTempTable ){
888 sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
889 }else if( pSelect ){
890 sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
891 }else{
892 VdbeOp *pOp;
893 sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, regRowid);
894 pOp = sqlite3VdbeGetOp(v, -1);
895 if( ALWAYS(pOp) && pOp->opcode==OP_Null && !IsVirtual(pTab) ){
896 appendFlag = 1;
897 pOp->opcode = OP_NewRowid;
898 pOp->p1 = baseCur;
899 pOp->p2 = regRowid;
900 pOp->p3 = regAutoinc;
901 }
902 }
903 /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
904 ** to generate a unique primary key value.
905 */
906 if( !appendFlag ){
907 int j1;
908 if( !IsVirtual(pTab) ){
909 j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regRowid);
910 sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
911 sqlite3VdbeJumpHere(v, j1);
912 }else{
913 j1 = sqlite3VdbeCurrentAddr(v);
914 sqlite3VdbeAddOp2(v, OP_IsNull, regRowid, j1+2);
915 }
916 sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid);
917 }
918 }else if( IsVirtual(pTab) ){
919 sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
920 }else{
921 sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
922 appendFlag = 1;
923 }
924 autoIncStep(pParse, regAutoinc, regRowid);
925
926 /* Push onto the stack, data for all columns of the new entry, beginning
927 ** with the first column.
928 */
929 nHidden = 0;
930 for(i=0; i<pTab->nCol; i++){
931 int iRegStore = regRowid+1+i;
932 if( i==pTab->iPKey ){
933 /* The value of the INTEGER PRIMARY KEY column is always a NULL.
934 ** Whenever this column is read, the record number will be substituted
935 ** in its place. So will fill this column with a NULL to avoid
936 ** taking up data space with information that will never be used. */
937 sqlite3VdbeAddOp2(v, OP_Null, 0, iRegStore);
938 continue;
939 }
940 if( pColumn==0 ){
941 if( IsHiddenColumn(&pTab->aCol[i]) ){
942 assert( IsVirtual(pTab) );
943 j = -1;
944 nHidden++;
945 }else{
946 j = i - nHidden;
947 }
948 }else{
949 for(j=0; j<pColumn->nId; j++){
950 if( pColumn->a[j].idx==i ) break;
951 }
952 }
953 if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
954 sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, iRegStore);
955 }else if( useTempTable ){
956 sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore);
957 }else if( pSelect ){
958 sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
959 }else{
960 sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);
961 }
962 }
963
964 /* Generate code to check constraints and generate index keys and
965 ** do the insertion.
966 */
967 #ifndef SQLITE_OMIT_VIRTUALTABLE
968 if( IsVirtual(pTab) ){
969 const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
970 sqlite3VtabMakeWritable(pParse, pTab);
971 sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
972 sqlite3MayAbort(pParse);
973 }else
974 #endif
975 {
976 int isReplace; /* Set to true if constraints may cause a replace */
977 sqlite3GenerateConstraintChecks(pParse, pTab, baseCur, regIns, aRegIdx,
978 keyColumn>=0, 0, onError, endOfLoop, &isReplace
979 );
980 sqlite3FkCheck(pParse, pTab, 0, regIns);
981 sqlite3CompleteInsertion(
982 pParse, pTab, baseCur, regIns, aRegIdx, 0, appendFlag, isReplace==0
983 );
984 }
985 }
986
987 /* Update the count of rows that are inserted
988 */
989 if( (db->flags & SQLITE_CountRows)!=0 ){
990 sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);
991 }
992
993 if( pTrigger ){
994 /* Code AFTER triggers */
995 sqlite3CodeRowTrigger(pParse, pTrigger, TK_INSERT, 0, TRIGGER_AFTER,
996 pTab, regData-2-pTab->nCol, onError, endOfLoop);
997 }
998
999 /* The bottom of the main insertion loop, if the data source
1000 ** is a SELECT statement.
1001 */
1002 sqlite3VdbeResolveLabel(v, endOfLoop);
1003 if( useTempTable ){
1004 sqlite3VdbeAddOp2(v, OP_Next, srcTab, addrCont);
1005 sqlite3VdbeJumpHere(v, addrInsTop);
1006 sqlite3VdbeAddOp1(v, OP_Close, srcTab);
1007 }else if( pSelect ){
1008 sqlite3VdbeAddOp2(v, OP_Goto, 0, addrCont);
1009 sqlite3VdbeJumpHere(v, addrInsTop);
1010 }
1011
1012 if( !IsVirtual(pTab) && !isView ){
1013 /* Close all tables opened */
1014 sqlite3VdbeAddOp1(v, OP_Close, baseCur);
1015 for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
1016 sqlite3VdbeAddOp1(v, OP_Close, idx+baseCur);
1017 }
1018 }
1019
1020 insert_end:
1021 /* Update the sqlite_sequence table by storing the content of the
1022 ** maximum rowid counter values recorded while inserting into
1023 ** autoincrement tables.
1024 */
1025 if( pParse->nested==0 && pParse->pTriggerTab==0 ){
1026 sqlite3AutoincrementEnd(pParse);
1027 }
1028
1029 /*
1030 ** Return the number of rows inserted. If this routine is
1031 ** generating code because of a call to sqlite3NestedParse(), do not
1032 ** invoke the callback function.
1033 */
1034 if( (db->flags&SQLITE_CountRows) && !pParse->nested && !pParse->pTriggerTab ){
1035 sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1);
1036 sqlite3VdbeSetNumCols(v, 1);
1037 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", SQLITE_STATIC);
1038 }
1039
1040 insert_cleanup:
1041 sqlite3SrcListDelete(db, pTabList);
1042 sqlite3ExprListDelete(db, pList);
1043 sqlite3SelectDelete(db, pSelect);
1044 sqlite3IdListDelete(db, pColumn);
1045 sqlite3DbFree(db, aRegIdx);
1046 }
1047
1048 /* Make sure "isView" and other macros defined above are undefined. Otherwise
1049 ** thely may interfere with compilation of other functions in this file
1050 ** (or in another file, if this file becomes part of the amalgamation). */
1051 #ifdef isView
1052 #undef isView
1053 #endif
1054 #ifdef pTrigger
1055 #undef pTrigger
1056 #endif
1057 #ifdef tmask
1058 #undef tmask
1059 #endif
1060
1061
1062 /*
1063 ** Generate code to do constraint checks prior to an INSERT or an UPDATE.
1064 **
1065 ** The input is a range of consecutive registers as follows:
1066 **
1067 ** 1. The rowid of the row after the update.
1068 **
1069 ** 2. The data in the first column of the entry after the update.
1070 **
1071 ** i. Data from middle columns...
1072 **
1073 ** N. The data in the last column of the entry after the update.
1074 **
1075 ** The regRowid parameter is the index of the register containing (1).
1076 **
1077 ** If isUpdate is true and rowidChng is non-zero, then rowidChng contains
1078 ** the address of a register containing the rowid before the update takes
1079 ** place. isUpdate is true for UPDATEs and false for INSERTs. If isUpdate
1080 ** is false, indicating an INSERT statement, then a non-zero rowidChng
1081 ** indicates that the rowid was explicitly specified as part of the
1082 ** INSERT statement. If rowidChng is false, it means that the rowid is
1083 ** computed automatically in an insert or that the rowid value is not
1084 ** modified by an update.
1085 **
1086 ** The code generated by this routine store new index entries into
1087 ** registers identified by aRegIdx[]. No index entry is created for
1088 ** indices where aRegIdx[i]==0. The order of indices in aRegIdx[] is
1089 ** the same as the order of indices on the linked list of indices
1090 ** attached to the table.
1091 **
1092 ** This routine also generates code to check constraints. NOT NULL,
1093 ** CHECK, and UNIQUE constraints are all checked. If a constraint fails,
1094 ** then the appropriate action is performed. There are five possible
1095 ** actions: ROLLBACK, ABORT, FAIL, REPLACE, and IGNORE.
1096 **
1097 ** Constraint type Action What Happens
1098 ** --------------- ---------- ----------------------------------------
1099 ** any ROLLBACK The current transaction is rolled back and
1100 ** sqlite3_exec() returns immediately with a
1101 ** return code of SQLITE_CONSTRAINT.
1102 **
1103 ** any ABORT Back out changes from the current command
1104 ** only (do not do a complete rollback) then
1105 ** cause sqlite3_exec() to return immediately
1106 ** with SQLITE_CONSTRAINT.
1107 **
1108 ** any FAIL Sqlite_exec() returns immediately with a
1109 ** return code of SQLITE_CONSTRAINT. The
1110 ** transaction is not rolled back and any
1111 ** prior changes are retained.
1112 **
1113 ** any IGNORE The record number and data is popped from
1114 ** the stack and there is an immediate jump
1115 ** to label ignoreDest.
1116 **
1117 ** NOT NULL REPLACE The NULL value is replace by the default
1118 ** value for that column. If the default value
1119 ** is NULL, the action is the same as ABORT.
1120 **
1121 ** UNIQUE REPLACE The other row that conflicts with the row
1122 ** being inserted is removed.
1123 **
1124 ** CHECK REPLACE Illegal. The results in an exception.
1125 **
1126 ** Which action to take is determined by the overrideError parameter.
1127 ** Or if overrideError==OE_Default, then the pParse->onError parameter
1128 ** is used. Or if pParse->onError==OE_Default then the onError value
1129 ** for the constraint is used.
1130 **
1131 ** The calling routine must open a read/write cursor for pTab with
1132 ** cursor number "baseCur". All indices of pTab must also have open
1133 ** read/write cursors with cursor number baseCur+i for the i-th cursor.
1134 ** Except, if there is no possibility of a REPLACE action then
1135 ** cursors do not need to be open for indices where aRegIdx[i]==0.
1136 */
sqlite3GenerateConstraintChecks(Parse * pParse,Table * pTab,int baseCur,int regRowid,int * aRegIdx,int rowidChng,int isUpdate,int overrideError,int ignoreDest,int * pbMayReplace)1137 void sqlite3GenerateConstraintChecks(
1138 Parse *pParse, /* The parser context */
1139 Table *pTab, /* the table into which we are inserting */
1140 int baseCur, /* Index of a read/write cursor pointing at pTab */
1141 int regRowid, /* Index of the range of input registers */
1142 int *aRegIdx, /* Register used by each index. 0 for unused indices */
1143 int rowidChng, /* True if the rowid might collide with existing entry */
1144 int isUpdate, /* True for UPDATE, False for INSERT */
1145 int overrideError, /* Override onError to this if not OE_Default */
1146 int ignoreDest, /* Jump to this label on an OE_Ignore resolution */
1147 int *pbMayReplace /* OUT: Set to true if constraint may cause a replace */
1148 ){
1149 int i; /* loop counter */
1150 Vdbe *v; /* VDBE under constrution */
1151 int nCol; /* Number of columns */
1152 int onError; /* Conflict resolution strategy */
1153 int j1; /* Addresss of jump instruction */
1154 int j2 = 0, j3; /* Addresses of jump instructions */
1155 int regData; /* Register containing first data column */
1156 int iCur; /* Table cursor number */
1157 Index *pIdx; /* Pointer to one of the indices */
1158 int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
1159 int regOldRowid = (rowidChng && isUpdate) ? rowidChng : regRowid;
1160
1161 v = sqlite3GetVdbe(pParse);
1162 assert( v!=0 );
1163 assert( pTab->pSelect==0 ); /* This table is not a VIEW */
1164 nCol = pTab->nCol;
1165 regData = regRowid + 1;
1166
1167 /* Test all NOT NULL constraints.
1168 */
1169 for(i=0; i<nCol; i++){
1170 if( i==pTab->iPKey ){
1171 continue;
1172 }
1173 onError = pTab->aCol[i].notNull;
1174 if( onError==OE_None ) continue;
1175 if( overrideError!=OE_Default ){
1176 onError = overrideError;
1177 }else if( onError==OE_Default ){
1178 onError = OE_Abort;
1179 }
1180 if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
1181 onError = OE_Abort;
1182 }
1183 assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1184 || onError==OE_Ignore || onError==OE_Replace );
1185 switch( onError ){
1186 case OE_Abort:
1187 sqlite3MayAbort(pParse);
1188 case OE_Rollback:
1189 case OE_Fail: {
1190 char *zMsg;
1191 sqlite3VdbeAddOp3(v, OP_HaltIfNull,
1192 SQLITE_CONSTRAINT, onError, regData+i);
1193 zMsg = sqlite3MPrintf(pParse->db, "%s.%s may not be NULL",
1194 pTab->zName, pTab->aCol[i].zName);
1195 sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
1196 break;
1197 }
1198 case OE_Ignore: {
1199 sqlite3VdbeAddOp2(v, OP_IsNull, regData+i, ignoreDest);
1200 break;
1201 }
1202 default: {
1203 assert( onError==OE_Replace );
1204 j1 = sqlite3VdbeAddOp1(v, OP_NotNull, regData+i);
1205 sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regData+i);
1206 sqlite3VdbeJumpHere(v, j1);
1207 break;
1208 }
1209 }
1210 }
1211
1212 /* Test all CHECK constraints
1213 */
1214 #ifndef SQLITE_OMIT_CHECK
1215 if( pTab->pCheck && (pParse->db->flags & SQLITE_IgnoreChecks)==0 ){
1216 int allOk = sqlite3VdbeMakeLabel(v);
1217 pParse->ckBase = regData;
1218 sqlite3ExprIfTrue(pParse, pTab->pCheck, allOk, SQLITE_JUMPIFNULL);
1219 onError = overrideError!=OE_Default ? overrideError : OE_Abort;
1220 if( onError==OE_Ignore ){
1221 sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
1222 }else{
1223 if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-15569-63625 */
1224 sqlite3HaltConstraint(pParse, onError, 0, 0);
1225 }
1226 sqlite3VdbeResolveLabel(v, allOk);
1227 }
1228 #endif /* !defined(SQLITE_OMIT_CHECK) */
1229
1230 /* If we have an INTEGER PRIMARY KEY, make sure the primary key
1231 ** of the new record does not previously exist. Except, if this
1232 ** is an UPDATE and the primary key is not changing, that is OK.
1233 */
1234 if( rowidChng ){
1235 onError = pTab->keyConf;
1236 if( overrideError!=OE_Default ){
1237 onError = overrideError;
1238 }else if( onError==OE_Default ){
1239 onError = OE_Abort;
1240 }
1241
1242 if( isUpdate ){
1243 j2 = sqlite3VdbeAddOp3(v, OP_Eq, regRowid, 0, rowidChng);
1244 }
1245 j3 = sqlite3VdbeAddOp3(v, OP_NotExists, baseCur, 0, regRowid);
1246 switch( onError ){
1247 default: {
1248 onError = OE_Abort;
1249 /* Fall thru into the next case */
1250 }
1251 case OE_Rollback:
1252 case OE_Abort:
1253 case OE_Fail: {
1254 sqlite3HaltConstraint(
1255 pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
1256 break;
1257 }
1258 case OE_Replace: {
1259 /* If there are DELETE triggers on this table and the
1260 ** recursive-triggers flag is set, call GenerateRowDelete() to
1261 ** remove the conflicting row from the the table. This will fire
1262 ** the triggers and remove both the table and index b-tree entries.
1263 **
1264 ** Otherwise, if there are no triggers or the recursive-triggers
1265 ** flag is not set, but the table has one or more indexes, call
1266 ** GenerateRowIndexDelete(). This removes the index b-tree entries
1267 ** only. The table b-tree entry will be replaced by the new entry
1268 ** when it is inserted.
1269 **
1270 ** If either GenerateRowDelete() or GenerateRowIndexDelete() is called,
1271 ** also invoke MultiWrite() to indicate that this VDBE may require
1272 ** statement rollback (if the statement is aborted after the delete
1273 ** takes place). Earlier versions called sqlite3MultiWrite() regardless,
1274 ** but being more selective here allows statements like:
1275 **
1276 ** REPLACE INTO t(rowid) VALUES($newrowid)
1277 **
1278 ** to run without a statement journal if there are no indexes on the
1279 ** table.
1280 */
1281 Trigger *pTrigger = 0;
1282 if( pParse->db->flags&SQLITE_RecTriggers ){
1283 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1284 }
1285 if( pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0) ){
1286 sqlite3MultiWrite(pParse);
1287 sqlite3GenerateRowDelete(
1288 pParse, pTab, baseCur, regRowid, 0, pTrigger, OE_Replace
1289 );
1290 }else if( pTab->pIndex ){
1291 sqlite3MultiWrite(pParse);
1292 sqlite3GenerateRowIndexDelete(pParse, pTab, baseCur, 0);
1293 }
1294 seenReplace = 1;
1295 break;
1296 }
1297 case OE_Ignore: {
1298 assert( seenReplace==0 );
1299 sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
1300 break;
1301 }
1302 }
1303 sqlite3VdbeJumpHere(v, j3);
1304 if( isUpdate ){
1305 sqlite3VdbeJumpHere(v, j2);
1306 }
1307 }
1308
1309 /* Test all UNIQUE constraints by creating entries for each UNIQUE
1310 ** index and making sure that duplicate entries do not already exist.
1311 ** Add the new records to the indices as we go.
1312 */
1313 for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
1314 int regIdx;
1315 int regR;
1316
1317 if( aRegIdx[iCur]==0 ) continue; /* Skip unused indices */
1318
1319 /* Create a key for accessing the index entry */
1320 regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
1321 for(i=0; i<pIdx->nColumn; i++){
1322 int idx = pIdx->aiColumn[i];
1323 if( idx==pTab->iPKey ){
1324 sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
1325 }else{
1326 sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
1327 }
1328 }
1329 sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
1330 sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
1331 sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
1332 sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn+1);
1333
1334 /* Find out what action to take in case there is an indexing conflict */
1335 onError = pIdx->onError;
1336 if( onError==OE_None ){
1337 sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
1338 continue; /* pIdx is not a UNIQUE index */
1339 }
1340 if( overrideError!=OE_Default ){
1341 onError = overrideError;
1342 }else if( onError==OE_Default ){
1343 onError = OE_Abort;
1344 }
1345 if( seenReplace ){
1346 if( onError==OE_Ignore ) onError = OE_Replace;
1347 else if( onError==OE_Fail ) onError = OE_Abort;
1348 }
1349
1350 /* Check to see if the new index entry will be unique */
1351 regR = sqlite3GetTempReg(pParse);
1352 sqlite3VdbeAddOp2(v, OP_SCopy, regOldRowid, regR);
1353 j3 = sqlite3VdbeAddOp4(v, OP_IsUnique, baseCur+iCur+1, 0,
1354 regR, SQLITE_INT_TO_PTR(regIdx),
1355 P4_INT32);
1356 sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
1357
1358 /* Generate code that executes if the new index entry is not unique */
1359 assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
1360 || onError==OE_Ignore || onError==OE_Replace );
1361 switch( onError ){
1362 case OE_Rollback:
1363 case OE_Abort:
1364 case OE_Fail: {
1365 int j;
1366 StrAccum errMsg;
1367 const char *zSep;
1368 char *zErr;
1369
1370 sqlite3StrAccumInit(&errMsg, 0, 0, 200);
1371 errMsg.db = pParse->db;
1372 zSep = pIdx->nColumn>1 ? "columns " : "column ";
1373 for(j=0; j<pIdx->nColumn; j++){
1374 char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
1375 sqlite3StrAccumAppend(&errMsg, zSep, -1);
1376 zSep = ", ";
1377 sqlite3StrAccumAppend(&errMsg, zCol, -1);
1378 }
1379 sqlite3StrAccumAppend(&errMsg,
1380 pIdx->nColumn>1 ? " are not unique" : " is not unique", -1);
1381 zErr = sqlite3StrAccumFinish(&errMsg);
1382 sqlite3HaltConstraint(pParse, onError, zErr, 0);
1383 sqlite3DbFree(errMsg.db, zErr);
1384 break;
1385 }
1386 case OE_Ignore: {
1387 assert( seenReplace==0 );
1388 sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
1389 break;
1390 }
1391 default: {
1392 Trigger *pTrigger = 0;
1393 assert( onError==OE_Replace );
1394 sqlite3MultiWrite(pParse);
1395 if( pParse->db->flags&SQLITE_RecTriggers ){
1396 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
1397 }
1398 sqlite3GenerateRowDelete(
1399 pParse, pTab, baseCur, regR, 0, pTrigger, OE_Replace
1400 );
1401 seenReplace = 1;
1402 break;
1403 }
1404 }
1405 sqlite3VdbeJumpHere(v, j3);
1406 sqlite3ReleaseTempReg(pParse, regR);
1407 }
1408
1409 if( pbMayReplace ){
1410 *pbMayReplace = seenReplace;
1411 }
1412 }
1413
1414 /*
1415 ** This routine generates code to finish the INSERT or UPDATE operation
1416 ** that was started by a prior call to sqlite3GenerateConstraintChecks.
1417 ** A consecutive range of registers starting at regRowid contains the
1418 ** rowid and the content to be inserted.
1419 **
1420 ** The arguments to this routine should be the same as the first six
1421 ** arguments to sqlite3GenerateConstraintChecks.
1422 */
sqlite3CompleteInsertion(Parse * pParse,Table * pTab,int baseCur,int regRowid,int * aRegIdx,int isUpdate,int appendBias,int useSeekResult)1423 void sqlite3CompleteInsertion(
1424 Parse *pParse, /* The parser context */
1425 Table *pTab, /* the table into which we are inserting */
1426 int baseCur, /* Index of a read/write cursor pointing at pTab */
1427 int regRowid, /* Range of content */
1428 int *aRegIdx, /* Register used by each index. 0 for unused indices */
1429 int isUpdate, /* True for UPDATE, False for INSERT */
1430 int appendBias, /* True if this is likely to be an append */
1431 int useSeekResult /* True to set the USESEEKRESULT flag on OP_[Idx]Insert */
1432 ){
1433 int i;
1434 Vdbe *v;
1435 int nIdx;
1436 Index *pIdx;
1437 u8 pik_flags;
1438 int regData;
1439 int regRec;
1440
1441 v = sqlite3GetVdbe(pParse);
1442 assert( v!=0 );
1443 assert( pTab->pSelect==0 ); /* This table is not a VIEW */
1444 for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
1445 for(i=nIdx-1; i>=0; i--){
1446 if( aRegIdx[i]==0 ) continue;
1447 sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
1448 if( useSeekResult ){
1449 sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
1450 }
1451 }
1452 regData = regRowid + 1;
1453 regRec = sqlite3GetTempReg(pParse);
1454 sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
1455 sqlite3TableAffinityStr(v, pTab);
1456 sqlite3ExprCacheAffinityChange(pParse, regData, pTab->nCol);
1457 if( pParse->nested ){
1458 pik_flags = 0;
1459 }else{
1460 pik_flags = OPFLAG_NCHANGE;
1461 pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
1462 }
1463 if( appendBias ){
1464 pik_flags |= OPFLAG_APPEND;
1465 }
1466 if( useSeekResult ){
1467 pik_flags |= OPFLAG_USESEEKRESULT;
1468 }
1469 sqlite3VdbeAddOp3(v, OP_Insert, baseCur, regRec, regRowid);
1470 if( !pParse->nested ){
1471 sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
1472 }
1473 sqlite3VdbeChangeP5(v, pik_flags);
1474 }
1475
1476 /*
1477 ** Generate code that will open cursors for a table and for all
1478 ** indices of that table. The "baseCur" parameter is the cursor number used
1479 ** for the table. Indices are opened on subsequent cursors.
1480 **
1481 ** Return the number of indices on the table.
1482 */
sqlite3OpenTableAndIndices(Parse * pParse,Table * pTab,int baseCur,int op)1483 int sqlite3OpenTableAndIndices(
1484 Parse *pParse, /* Parsing context */
1485 Table *pTab, /* Table to be opened */
1486 int baseCur, /* Cursor number assigned to the table */
1487 int op /* OP_OpenRead or OP_OpenWrite */
1488 ){
1489 int i;
1490 int iDb;
1491 Index *pIdx;
1492 Vdbe *v;
1493
1494 if( IsVirtual(pTab) ) return 0;
1495 iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
1496 v = sqlite3GetVdbe(pParse);
1497 assert( v!=0 );
1498 sqlite3OpenTable(pParse, baseCur, iDb, pTab, op);
1499 for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
1500 KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
1501 assert( pIdx->pSchema==pTab->pSchema );
1502 sqlite3VdbeAddOp4(v, op, i+baseCur, pIdx->tnum, iDb,
1503 (char*)pKey, P4_KEYINFO_HANDOFF);
1504 VdbeComment((v, "%s", pIdx->zName));
1505 }
1506 if( pParse->nTab<baseCur+i ){
1507 pParse->nTab = baseCur+i;
1508 }
1509 return i-1;
1510 }
1511
1512
1513 #ifdef SQLITE_TEST
1514 /*
1515 ** The following global variable is incremented whenever the
1516 ** transfer optimization is used. This is used for testing
1517 ** purposes only - to make sure the transfer optimization really
1518 ** is happening when it is suppose to.
1519 */
1520 int sqlite3_xferopt_count;
1521 #endif /* SQLITE_TEST */
1522
1523
1524 #ifndef SQLITE_OMIT_XFER_OPT
1525 /*
1526 ** Check to collation names to see if they are compatible.
1527 */
xferCompatibleCollation(const char * z1,const char * z2)1528 static int xferCompatibleCollation(const char *z1, const char *z2){
1529 if( z1==0 ){
1530 return z2==0;
1531 }
1532 if( z2==0 ){
1533 return 0;
1534 }
1535 return sqlite3StrICmp(z1, z2)==0;
1536 }
1537
1538
1539 /*
1540 ** Check to see if index pSrc is compatible as a source of data
1541 ** for index pDest in an insert transfer optimization. The rules
1542 ** for a compatible index:
1543 **
1544 ** * The index is over the same set of columns
1545 ** * The same DESC and ASC markings occurs on all columns
1546 ** * The same onError processing (OE_Abort, OE_Ignore, etc)
1547 ** * The same collating sequence on each column
1548 */
xferCompatibleIndex(Index * pDest,Index * pSrc)1549 static int xferCompatibleIndex(Index *pDest, Index *pSrc){
1550 int i;
1551 assert( pDest && pSrc );
1552 assert( pDest->pTable!=pSrc->pTable );
1553 if( pDest->nColumn!=pSrc->nColumn ){
1554 return 0; /* Different number of columns */
1555 }
1556 if( pDest->onError!=pSrc->onError ){
1557 return 0; /* Different conflict resolution strategies */
1558 }
1559 for(i=0; i<pSrc->nColumn; i++){
1560 if( pSrc->aiColumn[i]!=pDest->aiColumn[i] ){
1561 return 0; /* Different columns indexed */
1562 }
1563 if( pSrc->aSortOrder[i]!=pDest->aSortOrder[i] ){
1564 return 0; /* Different sort orders */
1565 }
1566 if( !xferCompatibleCollation(pSrc->azColl[i],pDest->azColl[i]) ){
1567 return 0; /* Different collating sequences */
1568 }
1569 }
1570
1571 /* If no test above fails then the indices must be compatible */
1572 return 1;
1573 }
1574
1575 /*
1576 ** Attempt the transfer optimization on INSERTs of the form
1577 **
1578 ** INSERT INTO tab1 SELECT * FROM tab2;
1579 **
1580 ** This optimization is only attempted if
1581 **
1582 ** (1) tab1 and tab2 have identical schemas including all the
1583 ** same indices and constraints
1584 **
1585 ** (2) tab1 and tab2 are different tables
1586 **
1587 ** (3) There must be no triggers on tab1
1588 **
1589 ** (4) The result set of the SELECT statement is "*"
1590 **
1591 ** (5) The SELECT statement has no WHERE, HAVING, ORDER BY, GROUP BY,
1592 ** or LIMIT clause.
1593 **
1594 ** (6) The SELECT statement is a simple (not a compound) select that
1595 ** contains only tab2 in its FROM clause
1596 **
1597 ** This method for implementing the INSERT transfers raw records from
1598 ** tab2 over to tab1. The columns are not decoded. Raw records from
1599 ** the indices of tab2 are transfered to tab1 as well. In so doing,
1600 ** the resulting tab1 has much less fragmentation.
1601 **
1602 ** This routine returns TRUE if the optimization is attempted. If any
1603 ** of the conditions above fail so that the optimization should not
1604 ** be attempted, then this routine returns FALSE.
1605 */
xferOptimization(Parse * pParse,Table * pDest,Select * pSelect,int onError,int iDbDest)1606 static int xferOptimization(
1607 Parse *pParse, /* Parser context */
1608 Table *pDest, /* The table we are inserting into */
1609 Select *pSelect, /* A SELECT statement to use as the data source */
1610 int onError, /* How to handle constraint errors */
1611 int iDbDest /* The database of pDest */
1612 ){
1613 ExprList *pEList; /* The result set of the SELECT */
1614 Table *pSrc; /* The table in the FROM clause of SELECT */
1615 Index *pSrcIdx, *pDestIdx; /* Source and destination indices */
1616 struct SrcList_item *pItem; /* An element of pSelect->pSrc */
1617 int i; /* Loop counter */
1618 int iDbSrc; /* The database of pSrc */
1619 int iSrc, iDest; /* Cursors from source and destination */
1620 int addr1, addr2; /* Loop addresses */
1621 int emptyDestTest; /* Address of test for empty pDest */
1622 int emptySrcTest; /* Address of test for empty pSrc */
1623 Vdbe *v; /* The VDBE we are building */
1624 KeyInfo *pKey; /* Key information for an index */
1625 int regAutoinc; /* Memory register used by AUTOINC */
1626 int destHasUniqueIdx = 0; /* True if pDest has a UNIQUE index */
1627 int regData, regRowid; /* Registers holding data and rowid */
1628
1629 if( pSelect==0 ){
1630 return 0; /* Must be of the form INSERT INTO ... SELECT ... */
1631 }
1632 if( sqlite3TriggerList(pParse, pDest) ){
1633 return 0; /* tab1 must not have triggers */
1634 }
1635 #ifndef SQLITE_OMIT_VIRTUALTABLE
1636 if( pDest->tabFlags & TF_Virtual ){
1637 return 0; /* tab1 must not be a virtual table */
1638 }
1639 #endif
1640 if( onError==OE_Default ){
1641 onError = OE_Abort;
1642 }
1643 if( onError!=OE_Abort && onError!=OE_Rollback ){
1644 return 0; /* Cannot do OR REPLACE or OR IGNORE or OR FAIL */
1645 }
1646 assert(pSelect->pSrc); /* allocated even if there is no FROM clause */
1647 if( pSelect->pSrc->nSrc!=1 ){
1648 return 0; /* FROM clause must have exactly one term */
1649 }
1650 if( pSelect->pSrc->a[0].pSelect ){
1651 return 0; /* FROM clause cannot contain a subquery */
1652 }
1653 if( pSelect->pWhere ){
1654 return 0; /* SELECT may not have a WHERE clause */
1655 }
1656 if( pSelect->pOrderBy ){
1657 return 0; /* SELECT may not have an ORDER BY clause */
1658 }
1659 /* Do not need to test for a HAVING clause. If HAVING is present but
1660 ** there is no ORDER BY, we will get an error. */
1661 if( pSelect->pGroupBy ){
1662 return 0; /* SELECT may not have a GROUP BY clause */
1663 }
1664 if( pSelect->pLimit ){
1665 return 0; /* SELECT may not have a LIMIT clause */
1666 }
1667 assert( pSelect->pOffset==0 ); /* Must be so if pLimit==0 */
1668 if( pSelect->pPrior ){
1669 return 0; /* SELECT may not be a compound query */
1670 }
1671 if( pSelect->selFlags & SF_Distinct ){
1672 return 0; /* SELECT may not be DISTINCT */
1673 }
1674 pEList = pSelect->pEList;
1675 assert( pEList!=0 );
1676 if( pEList->nExpr!=1 ){
1677 return 0; /* The result set must have exactly one column */
1678 }
1679 assert( pEList->a[0].pExpr );
1680 if( pEList->a[0].pExpr->op!=TK_ALL ){
1681 return 0; /* The result set must be the special operator "*" */
1682 }
1683
1684 /* At this point we have established that the statement is of the
1685 ** correct syntactic form to participate in this optimization. Now
1686 ** we have to check the semantics.
1687 */
1688 pItem = pSelect->pSrc->a;
1689 pSrc = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase);
1690 if( pSrc==0 ){
1691 return 0; /* FROM clause does not contain a real table */
1692 }
1693 if( pSrc==pDest ){
1694 return 0; /* tab1 and tab2 may not be the same table */
1695 }
1696 #ifndef SQLITE_OMIT_VIRTUALTABLE
1697 if( pSrc->tabFlags & TF_Virtual ){
1698 return 0; /* tab2 must not be a virtual table */
1699 }
1700 #endif
1701 if( pSrc->pSelect ){
1702 return 0; /* tab2 may not be a view */
1703 }
1704 if( pDest->nCol!=pSrc->nCol ){
1705 return 0; /* Number of columns must be the same in tab1 and tab2 */
1706 }
1707 if( pDest->iPKey!=pSrc->iPKey ){
1708 return 0; /* Both tables must have the same INTEGER PRIMARY KEY */
1709 }
1710 for(i=0; i<pDest->nCol; i++){
1711 if( pDest->aCol[i].affinity!=pSrc->aCol[i].affinity ){
1712 return 0; /* Affinity must be the same on all columns */
1713 }
1714 if( !xferCompatibleCollation(pDest->aCol[i].zColl, pSrc->aCol[i].zColl) ){
1715 return 0; /* Collating sequence must be the same on all columns */
1716 }
1717 if( pDest->aCol[i].notNull && !pSrc->aCol[i].notNull ){
1718 return 0; /* tab2 must be NOT NULL if tab1 is */
1719 }
1720 }
1721 for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
1722 if( pDestIdx->onError!=OE_None ){
1723 destHasUniqueIdx = 1;
1724 }
1725 for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
1726 if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
1727 }
1728 if( pSrcIdx==0 ){
1729 return 0; /* pDestIdx has no corresponding index in pSrc */
1730 }
1731 }
1732 #ifndef SQLITE_OMIT_CHECK
1733 if( pDest->pCheck && sqlite3ExprCompare(pSrc->pCheck, pDest->pCheck) ){
1734 return 0; /* Tables have different CHECK constraints. Ticket #2252 */
1735 }
1736 #endif
1737
1738 /* If we get this far, it means either:
1739 **
1740 ** * We can always do the transfer if the table contains an
1741 ** an integer primary key
1742 **
1743 ** * We can conditionally do the transfer if the destination
1744 ** table is empty.
1745 */
1746 #ifdef SQLITE_TEST
1747 sqlite3_xferopt_count++;
1748 #endif
1749 iDbSrc = sqlite3SchemaToIndex(pParse->db, pSrc->pSchema);
1750 v = sqlite3GetVdbe(pParse);
1751 sqlite3CodeVerifySchema(pParse, iDbSrc);
1752 iSrc = pParse->nTab++;
1753 iDest = pParse->nTab++;
1754 regAutoinc = autoIncBegin(pParse, iDbDest, pDest);
1755 sqlite3OpenTable(pParse, iDest, iDbDest, pDest, OP_OpenWrite);
1756 if( (pDest->iPKey<0 && pDest->pIndex!=0) || destHasUniqueIdx ){
1757 /* If tables do not have an INTEGER PRIMARY KEY and there
1758 ** are indices to be copied and the destination is not empty,
1759 ** we have to disallow the transfer optimization because the
1760 ** the rowids might change which will mess up indexing.
1761 **
1762 ** Or if the destination has a UNIQUE index and is not empty,
1763 ** we also disallow the transfer optimization because we cannot
1764 ** insure that all entries in the union of DEST and SRC will be
1765 ** unique.
1766 */
1767 addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0);
1768 emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
1769 sqlite3VdbeJumpHere(v, addr1);
1770 }else{
1771 emptyDestTest = 0;
1772 }
1773 sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
1774 emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
1775 regData = sqlite3GetTempReg(pParse);
1776 regRowid = sqlite3GetTempReg(pParse);
1777 if( pDest->iPKey>=0 ){
1778 addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
1779 addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
1780 sqlite3HaltConstraint(
1781 pParse, onError, "PRIMARY KEY must be unique", P4_STATIC);
1782 sqlite3VdbeJumpHere(v, addr2);
1783 autoIncStep(pParse, regAutoinc, regRowid);
1784 }else if( pDest->pIndex==0 ){
1785 addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
1786 }else{
1787 addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
1788 assert( (pDest->tabFlags & TF_Autoincrement)==0 );
1789 }
1790 sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
1791 sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
1792 sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
1793 sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
1794 sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1);
1795 for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
1796 for(pSrcIdx=pSrc->pIndex; ALWAYS(pSrcIdx); pSrcIdx=pSrcIdx->pNext){
1797 if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
1798 }
1799 assert( pSrcIdx );
1800 sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
1801 sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
1802 pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
1803 sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
1804 (char*)pKey, P4_KEYINFO_HANDOFF);
1805 VdbeComment((v, "%s", pSrcIdx->zName));
1806 pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
1807 sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
1808 (char*)pKey, P4_KEYINFO_HANDOFF);
1809 VdbeComment((v, "%s", pDestIdx->zName));
1810 addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
1811 sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
1812 sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
1813 sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
1814 sqlite3VdbeJumpHere(v, addr1);
1815 }
1816 sqlite3VdbeJumpHere(v, emptySrcTest);
1817 sqlite3ReleaseTempReg(pParse, regRowid);
1818 sqlite3ReleaseTempReg(pParse, regData);
1819 sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
1820 sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
1821 if( emptyDestTest ){
1822 sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
1823 sqlite3VdbeJumpHere(v, emptyDestTest);
1824 sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
1825 return 0;
1826 }else{
1827 return 1;
1828 }
1829 }
1830 #endif /* SQLITE_OMIT_XFER_OPT */
1831