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 UPDATE statements. 14 ** 15 ** $Id: update.c,v 1.141 2007/11/11 18:36:34 drh Exp $ 16 */ 17 #include "sqliteInt.h" 18 19 #ifndef SQLITE_OMIT_VIRTUALTABLE 20 /* Forward declaration */ 21 static void updateVirtualTable( 22 Parse *pParse, /* The parsing context */ 23 SrcList *pSrc, /* The virtual table to be modified */ 24 Table *pTab, /* The virtual table */ 25 ExprList *pChanges, /* The columns to change in the UPDATE statement */ 26 Expr *pRowidExpr, /* Expression used to recompute the rowid */ 27 int *aXRef, /* Mapping from columns of pTab to entries in pChanges */ 28 Expr *pWhere /* WHERE clause of the UPDATE statement */ 29 ); 30 #endif /* SQLITE_OMIT_VIRTUALTABLE */ 31 32 /* 33 ** The most recently coded instruction was an OP_Column to retrieve the 34 ** i-th column of table pTab. This routine sets the P3 parameter of the 35 ** OP_Column to the default value, if any. 36 ** 37 ** The default value of a column is specified by a DEFAULT clause in the 38 ** column definition. This was either supplied by the user when the table 39 ** was created, or added later to the table definition by an ALTER TABLE 40 ** command. If the latter, then the row-records in the table btree on disk 41 ** may not contain a value for the column and the default value, taken 42 ** from the P3 parameter of the OP_Column instruction, is returned instead. 43 ** If the former, then all row-records are guaranteed to include a value 44 ** for the column and the P3 value is not required. 45 ** 46 ** Column definitions created by an ALTER TABLE command may only have 47 ** literal default values specified: a number, null or a string. (If a more 48 ** complicated default expression value was provided, it is evaluated 49 ** when the ALTER TABLE is executed and one of the literal values written 50 ** into the sqlite_master table.) 51 ** 52 ** Therefore, the P3 parameter is only required if the default value for 53 ** the column is a literal number, string or null. The sqlite3ValueFromExpr() 54 ** function is capable of transforming these types of expressions into 55 ** sqlite3_value objects. 56 */ 57 void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i){ 58 if( pTab && !pTab->pSelect ){ 59 sqlite3_value *pValue; 60 u8 enc = ENC(sqlite3VdbeDb(v)); 61 Column *pCol = &pTab->aCol[i]; 62 assert( i<pTab->nCol ); 63 sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, pCol->affinity, &pValue); 64 if( pValue ){ 65 sqlite3VdbeChangeP3(v, -1, (const char *)pValue, P3_MEM); 66 }else{ 67 VdbeComment((v, "# %s.%s", pTab->zName, pCol->zName)); 68 } 69 } 70 } 71 72 /* 73 ** Process an UPDATE statement. 74 ** 75 ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; 76 ** \_______/ \________/ \______/ \________________/ 77 * onError pTabList pChanges pWhere 78 */ 79 void sqlite3Update( 80 Parse *pParse, /* The parser context */ 81 SrcList *pTabList, /* The table in which we should change things */ 82 ExprList *pChanges, /* Things to be changed */ 83 Expr *pWhere, /* The WHERE clause. May be null */ 84 int onError /* How to handle constraint errors */ 85 ){ 86 int i, j; /* Loop counters */ 87 Table *pTab; /* The table to be updated */ 88 int addr = 0; /* VDBE instruction address of the start of the loop */ 89 WhereInfo *pWInfo; /* Information about the WHERE clause */ 90 Vdbe *v; /* The virtual database engine */ 91 Index *pIdx; /* For looping over indices */ 92 int nIdx; /* Number of indices that need updating */ 93 int nIdxTotal; /* Total number of indices */ 94 int iCur; /* VDBE Cursor number of pTab */ 95 sqlite3 *db; /* The database structure */ 96 Index **apIdx = 0; /* An array of indices that need updating too */ 97 char *aIdxUsed = 0; /* aIdxUsed[i]==1 if the i-th index is used */ 98 int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the 99 ** an expression for the i-th column of the table. 100 ** aXRef[i]==-1 if the i-th column is not changed. */ 101 int chngRowid; /* True if the record number is being changed */ 102 Expr *pRowidExpr = 0; /* Expression defining the new record number */ 103 int openAll = 0; /* True if all indices need to be opened */ 104 AuthContext sContext; /* The authorization context */ 105 NameContext sNC; /* The name-context to resolve expressions in */ 106 int iDb; /* Database containing the table being updated */ 107 int memCnt = 0; /* Memory cell used for counting rows changed */ 108 109 #ifndef SQLITE_OMIT_TRIGGER 110 int isView; /* Trying to update a view */ 111 int triggers_exist = 0; /* True if any row triggers exist */ 112 #endif 113 114 int newIdx = -1; /* index of trigger "new" temp table */ 115 int oldIdx = -1; /* index of trigger "old" temp table */ 116 117 sContext.pParse = 0; 118 db = pParse->db; 119 if( pParse->nErr || db->mallocFailed ){ 120 goto update_cleanup; 121 } 122 assert( pTabList->nSrc==1 ); 123 124 /* Locate the table which we want to update. 125 */ 126 pTab = sqlite3SrcListLookup(pParse, pTabList); 127 if( pTab==0 ) goto update_cleanup; 128 iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); 129 130 /* Figure out if we have any triggers and if the table being 131 ** updated is a view 132 */ 133 #ifndef SQLITE_OMIT_TRIGGER 134 triggers_exist = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges); 135 isView = pTab->pSelect!=0; 136 #else 137 # define triggers_exist 0 138 # define isView 0 139 #endif 140 #ifdef SQLITE_OMIT_VIEW 141 # undef isView 142 # define isView 0 143 #endif 144 145 if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){ 146 goto update_cleanup; 147 } 148 if( sqlite3ViewGetColumnNames(pParse, pTab) ){ 149 goto update_cleanup; 150 } 151 aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol ); 152 if( aXRef==0 ) goto update_cleanup; 153 for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; 154 155 /* If there are FOR EACH ROW triggers, allocate cursors for the 156 ** special OLD and NEW tables 157 */ 158 if( triggers_exist ){ 159 newIdx = pParse->nTab++; 160 oldIdx = pParse->nTab++; 161 } 162 163 /* Allocate a cursors for the main database table and for all indices. 164 ** The index cursors might not be used, but if they are used they 165 ** need to occur right after the database cursor. So go ahead and 166 ** allocate enough space, just in case. 167 */ 168 pTabList->a[0].iCursor = iCur = pParse->nTab++; 169 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ 170 pParse->nTab++; 171 } 172 173 /* Initialize the name-context */ 174 memset(&sNC, 0, sizeof(sNC)); 175 sNC.pParse = pParse; 176 sNC.pSrcList = pTabList; 177 178 /* Resolve the column names in all the expressions of the 179 ** of the UPDATE statement. Also find the column index 180 ** for each column to be updated in the pChanges array. For each 181 ** column to be updated, make sure we have authorization to change 182 ** that column. 183 */ 184 chngRowid = 0; 185 for(i=0; i<pChanges->nExpr; i++){ 186 if( sqlite3ExprResolveNames(&sNC, pChanges->a[i].pExpr) ){ 187 goto update_cleanup; 188 } 189 for(j=0; j<pTab->nCol; j++){ 190 if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ 191 if( j==pTab->iPKey ){ 192 chngRowid = 1; 193 pRowidExpr = pChanges->a[i].pExpr; 194 } 195 aXRef[j] = i; 196 break; 197 } 198 } 199 if( j>=pTab->nCol ){ 200 if( sqlite3IsRowid(pChanges->a[i].zName) ){ 201 chngRowid = 1; 202 pRowidExpr = pChanges->a[i].pExpr; 203 }else{ 204 sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); 205 goto update_cleanup; 206 } 207 } 208 #ifndef SQLITE_OMIT_AUTHORIZATION 209 { 210 int rc; 211 rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, 212 pTab->aCol[j].zName, db->aDb[iDb].zName); 213 if( rc==SQLITE_DENY ){ 214 goto update_cleanup; 215 }else if( rc==SQLITE_IGNORE ){ 216 aXRef[j] = -1; 217 } 218 } 219 #endif 220 } 221 222 /* Allocate memory for the array apIdx[] and fill it with pointers to every 223 ** index that needs to be updated. Indices only need updating if their 224 ** key includes one of the columns named in pChanges or if the record 225 ** number of the original table entry is changing. 226 */ 227 for(nIdx=nIdxTotal=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdxTotal++){ 228 if( chngRowid ){ 229 i = 0; 230 }else { 231 for(i=0; i<pIdx->nColumn; i++){ 232 if( aXRef[pIdx->aiColumn[i]]>=0 ) break; 233 } 234 } 235 if( i<pIdx->nColumn ) nIdx++; 236 } 237 if( nIdxTotal>0 ){ 238 apIdx = sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx + nIdxTotal ); 239 if( apIdx==0 ) goto update_cleanup; 240 aIdxUsed = (char*)&apIdx[nIdx]; 241 } 242 for(nIdx=j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ 243 if( chngRowid ){ 244 i = 0; 245 }else{ 246 for(i=0; i<pIdx->nColumn; i++){ 247 if( aXRef[pIdx->aiColumn[i]]>=0 ) break; 248 } 249 } 250 if( i<pIdx->nColumn ){ 251 apIdx[nIdx++] = pIdx; 252 aIdxUsed[j] = 1; 253 }else{ 254 aIdxUsed[j] = 0; 255 } 256 } 257 258 /* Begin generating code. 259 */ 260 v = sqlite3GetVdbe(pParse); 261 if( v==0 ) goto update_cleanup; 262 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); 263 sqlite3BeginWriteOperation(pParse, 1, iDb); 264 265 #ifndef SQLITE_OMIT_VIRTUALTABLE 266 /* Virtual tables must be handled separately */ 267 if( IsVirtual(pTab) ){ 268 updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, 269 pWhere); 270 pWhere = 0; 271 pTabList = 0; 272 goto update_cleanup; 273 } 274 #endif 275 276 /* Resolve the column names in all the expressions in the 277 ** WHERE clause. 278 */ 279 if( sqlite3ExprResolveNames(&sNC, pWhere) ){ 280 goto update_cleanup; 281 } 282 283 /* Start the view context 284 */ 285 if( isView ){ 286 sqlite3AuthContextPush(pParse, &sContext, pTab->zName); 287 } 288 289 /* If we are trying to update a view, realize that view into 290 ** a ephemeral table. 291 */ 292 if( isView ){ 293 Select *pView; 294 pView = sqlite3SelectDup(db, pTab->pSelect); 295 sqlite3Select(pParse, pView, SRT_EphemTab, iCur, 0, 0, 0, 0); 296 sqlite3SelectDelete(pView); 297 } 298 299 /* Begin the database scan 300 */ 301 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0); 302 if( pWInfo==0 ) goto update_cleanup; 303 304 /* Remember the rowid of every item to be updated. 305 */ 306 sqlite3VdbeAddOp(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, 0); 307 sqlite3VdbeAddOp(v, OP_FifoWrite, 0, 0); 308 309 /* End the database scan loop. 310 */ 311 sqlite3WhereEnd(pWInfo); 312 313 /* Initialize the count of updated rows 314 */ 315 if( db->flags & SQLITE_CountRows && !pParse->trigStack ){ 316 memCnt = pParse->nMem++; 317 sqlite3VdbeAddOp(v, OP_MemInt, 0, memCnt); 318 } 319 320 if( triggers_exist ){ 321 int mem1; /* Memory address storing the rowid for next row to update */ 322 323 /* Create pseudo-tables for NEW and OLD 324 */ 325 sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0); 326 sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol); 327 sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0); 328 sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol); 329 330 /* The top of the update loop for when there are triggers. 331 */ 332 addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0); 333 mem1 = pParse->nMem++; 334 sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0); 335 336 if( !isView ){ 337 /* Open a cursor and make it point to the record that is 338 ** being updated. 339 */ 340 sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead); 341 } 342 sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0); 343 344 /* Generate the OLD table 345 */ 346 sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0); 347 sqlite3VdbeAddOp(v, OP_RowData, iCur, 0); 348 sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0); 349 350 /* Generate the NEW table 351 */ 352 if( chngRowid ){ 353 sqlite3ExprCodeAndCache(pParse, pRowidExpr); 354 }else{ 355 sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0); 356 } 357 for(i=0; i<pTab->nCol; i++){ 358 if( i==pTab->iPKey ){ 359 sqlite3VdbeAddOp(v, OP_Null, 0, 0); 360 continue; 361 } 362 j = aXRef[i]; 363 if( j<0 ){ 364 sqlite3VdbeAddOp(v, OP_Column, iCur, i); 365 sqlite3ColumnDefault(v, pTab, i); 366 }else{ 367 sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr); 368 } 369 } 370 sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0); 371 if( !isView ){ 372 sqlite3TableAffinityStr(v, pTab); 373 } 374 if( pParse->nErr ) goto update_cleanup; 375 sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0); 376 if( !isView ){ 377 sqlite3VdbeAddOp(v, OP_Close, iCur, 0); 378 } 379 380 /* Fire the BEFORE and INSTEAD OF triggers 381 */ 382 if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, 383 newIdx, oldIdx, onError, addr) ){ 384 goto update_cleanup; 385 } 386 387 if( !isView ){ 388 sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0); 389 sqlite3VdbeAddOp(v, OP_Dup, 0, 0); 390 } 391 } 392 393 if( !isView && !IsVirtual(pTab) ){ 394 /* 395 ** Open every index that needs updating. Note that if any 396 ** index could potentially invoke a REPLACE conflict resolution 397 ** action, then we need to open all indices because we might need 398 ** to be deleting some records. 399 */ 400 sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); 401 if( onError==OE_Replace ){ 402 openAll = 1; 403 }else{ 404 openAll = 0; 405 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ 406 if( pIdx->onError==OE_Replace ){ 407 openAll = 1; 408 break; 409 } 410 } 411 } 412 for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ 413 if( openAll || aIdxUsed[i] ){ 414 KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); 415 sqlite3VdbeAddOp(v, OP_Integer, iDb, 0); 416 sqlite3VdbeOp3(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, 417 (char*)pKey, P3_KEYINFO_HANDOFF); 418 assert( pParse->nTab>iCur+i+1 ); 419 } 420 } 421 422 /* Loop over every record that needs updating. We have to load 423 ** the old data for each record to be updated because some columns 424 ** might not change and we will need to copy the old value. 425 ** Also, the old data is needed to delete the old index entries. 426 ** So make the cursor point at the old record. 427 */ 428 if( !triggers_exist ){ 429 addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0); 430 sqlite3VdbeAddOp(v, OP_Dup, 0, 0); 431 } 432 sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr); 433 434 /* If the record number will change, push the record number as it 435 ** will be after the update. (The old record number is currently 436 ** on top of the stack.) 437 */ 438 if( chngRowid ){ 439 sqlite3ExprCode(pParse, pRowidExpr); 440 sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0); 441 } 442 443 /* Compute new data for this record. 444 */ 445 for(i=0; i<pTab->nCol; i++){ 446 if( i==pTab->iPKey ){ 447 sqlite3VdbeAddOp(v, OP_Null, 0, 0); 448 continue; 449 } 450 j = aXRef[i]; 451 if( j<0 ){ 452 sqlite3VdbeAddOp(v, OP_Column, iCur, i); 453 sqlite3ColumnDefault(v, pTab, i); 454 }else{ 455 sqlite3ExprCode(pParse, pChanges->a[j].pExpr); 456 } 457 } 458 459 /* Do constraint checks 460 */ 461 sqlite3GenerateConstraintChecks(pParse, pTab, iCur, aIdxUsed, chngRowid, 1, 462 onError, addr); 463 464 /* Delete the old indices for the current record. 465 */ 466 sqlite3GenerateRowIndexDelete(v, pTab, iCur, aIdxUsed); 467 468 /* If changing the record number, delete the old record. 469 */ 470 if( chngRowid ){ 471 sqlite3VdbeAddOp(v, OP_Delete, iCur, 0); 472 } 473 474 /* Create the new index entries and the new record. 475 */ 476 sqlite3CompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRowid, 1, -1, 0); 477 } 478 479 /* Increment the row counter 480 */ 481 if( db->flags & SQLITE_CountRows && !pParse->trigStack){ 482 sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt); 483 } 484 485 /* If there are triggers, close all the cursors after each iteration 486 ** through the loop. The fire the after triggers. 487 */ 488 if( triggers_exist ){ 489 if( !isView ){ 490 for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ 491 if( openAll || aIdxUsed[i] ) 492 sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0); 493 } 494 sqlite3VdbeAddOp(v, OP_Close, iCur, 0); 495 } 496 if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 497 newIdx, oldIdx, onError, addr) ){ 498 goto update_cleanup; 499 } 500 } 501 502 /* Repeat the above with the next record to be updated, until 503 ** all record selected by the WHERE clause have been updated. 504 */ 505 sqlite3VdbeAddOp(v, OP_Goto, 0, addr); 506 sqlite3VdbeJumpHere(v, addr); 507 508 /* Close all tables if there were no FOR EACH ROW triggers */ 509 if( !triggers_exist ){ 510 for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ 511 if( openAll || aIdxUsed[i] ){ 512 sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0); 513 } 514 } 515 sqlite3VdbeAddOp(v, OP_Close, iCur, 0); 516 }else{ 517 sqlite3VdbeAddOp(v, OP_Close, newIdx, 0); 518 sqlite3VdbeAddOp(v, OP_Close, oldIdx, 0); 519 } 520 521 /* 522 ** Return the number of rows that were changed. If this routine is 523 ** generating code because of a call to sqlite3NestedParse(), do not 524 ** invoke the callback function. 525 */ 526 if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){ 527 sqlite3VdbeAddOp(v, OP_MemLoad, memCnt, 0); 528 sqlite3VdbeAddOp(v, OP_Callback, 1, 0); 529 sqlite3VdbeSetNumCols(v, 1); 530 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", P3_STATIC); 531 } 532 533 update_cleanup: 534 sqlite3AuthContextPop(&sContext); 535 sqlite3_free(apIdx); 536 sqlite3_free(aXRef); 537 sqlite3SrcListDelete(pTabList); 538 sqlite3ExprListDelete(pChanges); 539 sqlite3ExprDelete(pWhere); 540 return; 541 } 542 543 #ifndef SQLITE_OMIT_VIRTUALTABLE 544 /* 545 ** Generate code for an UPDATE of a virtual table. 546 ** 547 ** The strategy is that we create an ephemerial table that contains 548 ** for each row to be changed: 549 ** 550 ** (A) The original rowid of that row. 551 ** (B) The revised rowid for the row. (note1) 552 ** (C) The content of every column in the row. 553 ** 554 ** Then we loop over this ephemeral table and for each row in 555 ** the ephermeral table call VUpdate. 556 ** 557 ** When finished, drop the ephemeral table. 558 ** 559 ** (note1) Actually, if we know in advance that (A) is always the same 560 ** as (B) we only store (A), then duplicate (A) when pulling 561 ** it out of the ephemeral table before calling VUpdate. 562 */ 563 static void updateVirtualTable( 564 Parse *pParse, /* The parsing context */ 565 SrcList *pSrc, /* The virtual table to be modified */ 566 Table *pTab, /* The virtual table */ 567 ExprList *pChanges, /* The columns to change in the UPDATE statement */ 568 Expr *pRowid, /* Expression used to recompute the rowid */ 569 int *aXRef, /* Mapping from columns of pTab to entries in pChanges */ 570 Expr *pWhere /* WHERE clause of the UPDATE statement */ 571 ){ 572 Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */ 573 ExprList *pEList = 0; /* The result set of the SELECT statement */ 574 Select *pSelect = 0; /* The SELECT statement */ 575 Expr *pExpr; /* Temporary expression */ 576 int ephemTab; /* Table holding the result of the SELECT */ 577 int i; /* Loop counter */ 578 int addr; /* Address of top of loop */ 579 sqlite3 *db = pParse->db; /* Database connection */ 580 581 /* Construct the SELECT statement that will find the new values for 582 ** all updated rows. 583 */ 584 pEList = sqlite3ExprListAppend(pParse, 0, 585 sqlite3CreateIdExpr(pParse, "_rowid_"), 0); 586 if( pRowid ){ 587 pEList = sqlite3ExprListAppend(pParse, pEList, 588 sqlite3ExprDup(db, pRowid), 0); 589 } 590 assert( pTab->iPKey<0 ); 591 for(i=0; i<pTab->nCol; i++){ 592 if( aXRef[i]>=0 ){ 593 pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr); 594 }else{ 595 pExpr = sqlite3CreateIdExpr(pParse, pTab->aCol[i].zName); 596 } 597 pEList = sqlite3ExprListAppend(pParse, pEList, pExpr, 0); 598 } 599 pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0); 600 601 /* Create the ephemeral table into which the update results will 602 ** be stored. 603 */ 604 assert( v ); 605 ephemTab = pParse->nTab++; 606 sqlite3VdbeAddOp(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0)); 607 608 /* fill the ephemeral table 609 */ 610 sqlite3Select(pParse, pSelect, SRT_Table, ephemTab, 0, 0, 0, 0); 611 612 /* 613 ** Generate code to scan the ephemeral table and call VDelete and 614 ** VInsert 615 */ 616 sqlite3VdbeAddOp(v, OP_Rewind, ephemTab, 0); 617 addr = sqlite3VdbeCurrentAddr(v); 618 sqlite3VdbeAddOp(v, OP_Column, ephemTab, 0); 619 if( pRowid ){ 620 sqlite3VdbeAddOp(v, OP_Column, ephemTab, 1); 621 }else{ 622 sqlite3VdbeAddOp(v, OP_Dup, 0, 0); 623 } 624 for(i=0; i<pTab->nCol; i++){ 625 sqlite3VdbeAddOp(v, OP_Column, ephemTab, i+1+(pRowid!=0)); 626 } 627 pParse->pVirtualLock = pTab; 628 sqlite3VdbeOp3(v, OP_VUpdate, 0, pTab->nCol+2, 629 (const char*)pTab->pVtab, P3_VTAB); 630 sqlite3VdbeAddOp(v, OP_Next, ephemTab, addr); 631 sqlite3VdbeJumpHere(v, addr-1); 632 sqlite3VdbeAddOp(v, OP_Close, ephemTab, 0); 633 634 /* Cleanup */ 635 sqlite3SelectDelete(pSelect); 636 } 637 #endif /* SQLITE_OMIT_VIRTUALTABLE */ 638