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 ** in order to generate code for DELETE FROM statements. 14 ** 15 ** $Id: delete.c,v 1.200 2009/04/30 00:11:10 drh Exp $ 16 */ 17 #include "sqliteInt.h" 18 19 /* 20 ** Look up every table that is named in pSrc. If any table is not found, 21 ** add an error message to pParse->zErrMsg and return NULL. If all tables 22 ** are found, return a pointer to the last table. 23 */ 24 Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){ 25 struct SrcList_item *pItem = pSrc->a; 26 Table *pTab; 27 assert( pItem && pSrc->nSrc==1 ); 28 pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase); 29 sqlite3DeleteTable(pItem->pTab); 30 pItem->pTab = pTab; 31 if( pTab ){ 32 pTab->nRef++; 33 } 34 if( sqlite3IndexedByLookup(pParse, pItem) ){ 35 pTab = 0; 36 } 37 return pTab; 38 } 39 40 /* 41 ** Check to make sure the given table is writable. If it is not 42 ** writable, generate an error message and return 1. If it is 43 ** writable return 0; 44 */ 45 int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){ 46 if( ((pTab->tabFlags & TF_Readonly)!=0 47 && (pParse->db->flags & SQLITE_WriteSchema)==0 48 && pParse->nested==0) 49 #ifndef SQLITE_OMIT_VIRTUALTABLE 50 || (pTab->pMod && pTab->pMod->pModule->xUpdate==0) 51 #endif 52 ){ 53 sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName); 54 return 1; 55 } 56 #ifndef SQLITE_OMIT_VIEW 57 if( !viewOk && pTab->pSelect ){ 58 sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName); 59 return 1; 60 } 61 #endif 62 return 0; 63 } 64 65 66 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) 67 /* 68 ** Evaluate a view and store its result in an ephemeral table. The 69 ** pWhere argument is an optional WHERE clause that restricts the 70 ** set of rows in the view that are to be added to the ephemeral table. 71 */ 72 void sqlite3MaterializeView( 73 Parse *pParse, /* Parsing context */ 74 Table *pView, /* View definition */ 75 Expr *pWhere, /* Optional WHERE clause to be added */ 76 int iCur /* Cursor number for ephemerial table */ 77 ){ 78 SelectDest dest; 79 Select *pDup; 80 sqlite3 *db = pParse->db; 81 82 pDup = sqlite3SelectDup(db, pView->pSelect, 0); 83 if( pWhere ){ 84 SrcList *pFrom; 85 Token viewName; 86 87 pWhere = sqlite3ExprDup(db, pWhere, 0); 88 viewName.z = (u8*)pView->zName; 89 viewName.n = (unsigned int)sqlite3Strlen30((const char*)viewName.z); 90 pFrom = sqlite3SrcListAppendFromTerm(pParse, 0, 0, 0, &viewName, pDup, 0,0); 91 pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0); 92 } 93 sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur); 94 sqlite3Select(pParse, pDup, &dest); 95 sqlite3SelectDelete(db, pDup); 96 } 97 #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */ 98 99 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) 100 /* 101 ** Generate an expression tree to implement the WHERE, ORDER BY, 102 ** and LIMIT/OFFSET portion of DELETE and UPDATE statements. 103 ** 104 ** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1; 105 ** \__________________________/ 106 ** pLimitWhere (pInClause) 107 */ 108 Expr *sqlite3LimitWhere( 109 Parse *pParse, /* The parser context */ 110 SrcList *pSrc, /* the FROM clause -- which tables to scan */ 111 Expr *pWhere, /* The WHERE clause. May be null */ 112 ExprList *pOrderBy, /* The ORDER BY clause. May be null */ 113 Expr *pLimit, /* The LIMIT clause. May be null */ 114 Expr *pOffset, /* The OFFSET clause. May be null */ 115 char *zStmtType /* Either DELETE or UPDATE. For error messages. */ 116 ){ 117 Expr *pWhereRowid = NULL; /* WHERE rowid .. */ 118 Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */ 119 Expr *pSelectRowid = NULL; /* SELECT rowid ... */ 120 ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */ 121 SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */ 122 Select *pSelect = NULL; /* Complete SELECT tree */ 123 124 /* Check that there isn't an ORDER BY without a LIMIT clause. 125 */ 126 if( pOrderBy && (pLimit == 0) ) { 127 sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType); 128 pParse->parseError = 1; 129 goto limit_where_cleanup_2; 130 } 131 132 /* We only need to generate a select expression if there 133 ** is a limit/offset term to enforce. 134 */ 135 if( pLimit == 0 ) { 136 /* if pLimit is null, pOffset will always be null as well. */ 137 assert( pOffset == 0 ); 138 return pWhere; 139 } 140 141 /* Generate a select expression tree to enforce the limit/offset 142 ** term for the DELETE or UPDATE statement. For example: 143 ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1 144 ** becomes: 145 ** DELETE FROM table_a WHERE rowid IN ( 146 ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1 147 ** ); 148 */ 149 150 pSelectRowid = sqlite3Expr(pParse->db, TK_ROW, 0, 0, 0); 151 if( pSelectRowid == 0 ) goto limit_where_cleanup_2; 152 pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid, 0); 153 if( pEList == 0 ) goto limit_where_cleanup_2; 154 155 /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree 156 ** and the SELECT subtree. */ 157 pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0); 158 if( pSelectSrc == 0 ) { 159 sqlite3ExprListDelete(pParse->db, pEList); 160 goto limit_where_cleanup_2; 161 } 162 163 /* generate the SELECT expression tree. */ 164 pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0, 165 pOrderBy,0,pLimit,pOffset); 166 if( pSelect == 0 ) return 0; 167 168 /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */ 169 pWhereRowid = sqlite3Expr(pParse->db, TK_ROW, 0, 0, 0); 170 if( pWhereRowid == 0 ) goto limit_where_cleanup_1; 171 pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0); 172 if( pInClause == 0 ) goto limit_where_cleanup_1; 173 174 pInClause->x.pSelect = pSelect; 175 pInClause->flags |= EP_xIsSelect; 176 sqlite3ExprSetHeight(pParse, pInClause); 177 return pInClause; 178 179 /* something went wrong. clean up anything allocated. */ 180 limit_where_cleanup_1: 181 sqlite3SelectDelete(pParse->db, pSelect); 182 return 0; 183 184 limit_where_cleanup_2: 185 sqlite3ExprDelete(pParse->db, pWhere); 186 sqlite3ExprListDelete(pParse->db, pOrderBy); 187 sqlite3ExprDelete(pParse->db, pLimit); 188 sqlite3ExprDelete(pParse->db, pOffset); 189 return 0; 190 } 191 #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */ 192 193 /* 194 ** Generate code for a DELETE FROM statement. 195 ** 196 ** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL; 197 ** \________/ \________________/ 198 ** pTabList pWhere 199 */ 200 void sqlite3DeleteFrom( 201 Parse *pParse, /* The parser context */ 202 SrcList *pTabList, /* The table from which we should delete things */ 203 Expr *pWhere /* The WHERE clause. May be null */ 204 ){ 205 Vdbe *v; /* The virtual database engine */ 206 Table *pTab; /* The table from which records will be deleted */ 207 const char *zDb; /* Name of database holding pTab */ 208 int end, addr = 0; /* A couple addresses of generated code */ 209 int i; /* Loop counter */ 210 WhereInfo *pWInfo; /* Information about the WHERE clause */ 211 Index *pIdx; /* For looping over indices of the table */ 212 int iCur; /* VDBE Cursor number for pTab */ 213 sqlite3 *db; /* Main database structure */ 214 AuthContext sContext; /* Authorization context */ 215 int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */ 216 NameContext sNC; /* Name context to resolve expressions in */ 217 int iDb; /* Database number */ 218 int memCnt = -1; /* Memory cell used for change counting */ 219 int rcauth; /* Value returned by authorization callback */ 220 221 #ifndef SQLITE_OMIT_TRIGGER 222 int isView; /* True if attempting to delete from a view */ 223 Trigger *pTrigger; /* List of table triggers, if required */ 224 #endif 225 int iBeginAfterTrigger = 0; /* Address of after trigger program */ 226 int iEndAfterTrigger = 0; /* Exit of after trigger program */ 227 int iBeginBeforeTrigger = 0; /* Address of before trigger program */ 228 int iEndBeforeTrigger = 0; /* Exit of before trigger program */ 229 u32 old_col_mask = 0; /* Mask of OLD.* columns in use */ 230 231 sContext.pParse = 0; 232 db = pParse->db; 233 if( pParse->nErr || db->mallocFailed ){ 234 goto delete_from_cleanup; 235 } 236 assert( pTabList->nSrc==1 ); 237 238 /* Locate the table which we want to delete. This table has to be 239 ** put in an SrcList structure because some of the subroutines we 240 ** will be calling are designed to work with multiple tables and expect 241 ** an SrcList* parameter instead of just a Table* parameter. 242 */ 243 pTab = sqlite3SrcListLookup(pParse, pTabList); 244 if( pTab==0 ) goto delete_from_cleanup; 245 246 /* Figure out if we have any triggers and if the table being 247 ** deleted from is a view 248 */ 249 #ifndef SQLITE_OMIT_TRIGGER 250 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0); 251 isView = pTab->pSelect!=0; 252 #else 253 # define pTrigger 0 254 # define isView 0 255 #endif 256 #ifdef SQLITE_OMIT_VIEW 257 # undef isView 258 # define isView 0 259 #endif 260 261 if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){ 262 goto delete_from_cleanup; 263 } 264 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); 265 assert( iDb<db->nDb ); 266 zDb = db->aDb[iDb].zName; 267 rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb); 268 assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE ); 269 if( rcauth==SQLITE_DENY ){ 270 goto delete_from_cleanup; 271 } 272 assert(!isView || pTrigger); 273 274 /* If pTab is really a view, make sure it has been initialized. 275 */ 276 if( sqlite3ViewGetColumnNames(pParse, pTab) ){ 277 goto delete_from_cleanup; 278 } 279 280 /* Allocate a cursor used to store the old.* data for a trigger. 281 */ 282 if( pTrigger ){ 283 oldIdx = pParse->nTab++; 284 } 285 286 /* Assign cursor number to the table and all its indices. 287 */ 288 assert( pTabList->nSrc==1 ); 289 iCur = pTabList->a[0].iCursor = pParse->nTab++; 290 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ 291 pParse->nTab++; 292 } 293 294 /* Start the view context 295 */ 296 if( isView ){ 297 sqlite3AuthContextPush(pParse, &sContext, pTab->zName); 298 } 299 300 /* Begin generating code. 301 */ 302 v = sqlite3GetVdbe(pParse); 303 if( v==0 ){ 304 goto delete_from_cleanup; 305 } 306 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); 307 sqlite3BeginWriteOperation(pParse, (pTrigger?1:0), iDb); 308 309 if( pTrigger ){ 310 int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default); 311 int iGoto = sqlite3VdbeAddOp0(v, OP_Goto); 312 addr = sqlite3VdbeMakeLabel(v); 313 314 iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v); 315 (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, 316 TRIGGER_BEFORE, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0); 317 iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto); 318 319 iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v); 320 (void)sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, 321 TRIGGER_AFTER, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0); 322 iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto); 323 324 sqlite3VdbeJumpHere(v, iGoto); 325 } 326 327 /* If we are trying to delete from a view, realize that view into 328 ** a ephemeral table. 329 */ 330 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) 331 if( isView ){ 332 sqlite3MaterializeView(pParse, pTab, pWhere, iCur); 333 } 334 #endif 335 336 /* Resolve the column names in the WHERE clause. 337 */ 338 memset(&sNC, 0, sizeof(sNC)); 339 sNC.pParse = pParse; 340 sNC.pSrcList = pTabList; 341 if( sqlite3ResolveExprNames(&sNC, pWhere) ){ 342 goto delete_from_cleanup; 343 } 344 345 /* Initialize the counter of the number of rows deleted, if 346 ** we are counting rows. 347 */ 348 if( db->flags & SQLITE_CountRows ){ 349 memCnt = ++pParse->nMem; 350 sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt); 351 } 352 353 #ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION 354 /* Special case: A DELETE without a WHERE clause deletes everything. 355 ** It is easier just to erase the whole table. Note, however, that 356 ** this means that the row change count will be incorrect. 357 */ 358 if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) ){ 359 assert( !isView ); 360 sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt, 361 pTab->zName, P4_STATIC); 362 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ 363 assert( pIdx->pSchema==pTab->pSchema ); 364 sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb); 365 } 366 }else 367 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */ 368 /* The usual case: There is a WHERE clause so we have to scan through 369 ** the table and pick which records to delete. 370 */ 371 { 372 int iRowid = ++pParse->nMem; /* Used for storing rowid values. */ 373 int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */ 374 int regRowid; /* Actual register containing rowids */ 375 376 /* Collect rowids of every row to be deleted. 377 */ 378 sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet); 379 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,WHERE_DUPLICATES_OK); 380 if( pWInfo==0 ) goto delete_from_cleanup; 381 regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid, 0); 382 sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid); 383 if( db->flags & SQLITE_CountRows ){ 384 sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1); 385 } 386 sqlite3WhereEnd(pWInfo); 387 388 /* Open the pseudo-table used to store OLD if there are triggers. 389 */ 390 if( pTrigger ){ 391 sqlite3VdbeAddOp3(v, OP_OpenPseudo, oldIdx, 0, pTab->nCol); 392 } 393 394 /* Delete every item whose key was written to the list during the 395 ** database scan. We have to delete items after the scan is complete 396 ** because deleting an item can change the scan order. 397 */ 398 end = sqlite3VdbeMakeLabel(v); 399 400 if( !isView ){ 401 /* Open cursors for the table we are deleting from and 402 ** all its indices. 403 */ 404 sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite); 405 } 406 407 /* This is the beginning of the delete loop. If a trigger encounters 408 ** an IGNORE constraint, it jumps back to here. 409 */ 410 if( pTrigger ){ 411 sqlite3VdbeResolveLabel(v, addr); 412 } 413 addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid); 414 415 if( pTrigger ){ 416 int iData = ++pParse->nMem; /* For storing row data of OLD table */ 417 418 /* If the record is no longer present in the table, jump to the 419 ** next iteration of the loop through the contents of the fifo. 420 */ 421 sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid); 422 423 /* Populate the OLD.* pseudo-table */ 424 if( old_col_mask ){ 425 sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData); 426 }else{ 427 sqlite3VdbeAddOp2(v, OP_Null, 0, iData); 428 } 429 sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid); 430 431 /* Jump back and run the BEFORE triggers */ 432 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger); 433 sqlite3VdbeJumpHere(v, iEndBeforeTrigger); 434 } 435 436 if( !isView ){ 437 /* Delete the row */ 438 #ifndef SQLITE_OMIT_VIRTUALTABLE 439 if( IsVirtual(pTab) ){ 440 const char *pVtab = (const char *)pTab->pVtab; 441 sqlite3VtabMakeWritable(pParse, pTab); 442 sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB); 443 }else 444 #endif 445 { 446 sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0); 447 } 448 } 449 450 /* If there are row triggers, close all cursors then invoke 451 ** the AFTER triggers 452 */ 453 if( pTrigger ){ 454 /* Jump back and run the AFTER triggers */ 455 sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger); 456 sqlite3VdbeJumpHere(v, iEndAfterTrigger); 457 } 458 459 /* End of the delete loop */ 460 sqlite3VdbeAddOp2(v, OP_Goto, 0, addr); 461 sqlite3VdbeResolveLabel(v, end); 462 463 /* Close the cursors after the loop if there are no row triggers */ 464 if( !isView && !IsVirtual(pTab) ){ 465 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ 466 sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum); 467 } 468 sqlite3VdbeAddOp1(v, OP_Close, iCur); 469 } 470 } 471 472 /* 473 ** Return the number of rows that were deleted. If this routine is 474 ** generating code because of a call to sqlite3NestedParse(), do not 475 ** invoke the callback function. 476 */ 477 if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){ 478 sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1); 479 sqlite3VdbeSetNumCols(v, 1); 480 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC); 481 } 482 483 delete_from_cleanup: 484 sqlite3AuthContextPop(&sContext); 485 sqlite3SrcListDelete(db, pTabList); 486 sqlite3ExprDelete(db, pWhere); 487 return; 488 } 489 490 /* 491 ** This routine generates VDBE code that causes a single row of a 492 ** single table to be deleted. 493 ** 494 ** The VDBE must be in a particular state when this routine is called. 495 ** These are the requirements: 496 ** 497 ** 1. A read/write cursor pointing to pTab, the table containing the row 498 ** to be deleted, must be opened as cursor number "base". 499 ** 500 ** 2. Read/write cursors for all indices of pTab must be open as 501 ** cursor number base+i for the i-th index. 502 ** 503 ** 3. The record number of the row to be deleted must be stored in 504 ** memory cell iRowid. 505 ** 506 ** This routine pops the top of the stack to remove the record number 507 ** and then generates code to remove both the table record and all index 508 ** entries that point to that record. 509 */ 510 void sqlite3GenerateRowDelete( 511 Parse *pParse, /* Parsing context */ 512 Table *pTab, /* Table containing the row to be deleted */ 513 int iCur, /* Cursor number for the table */ 514 int iRowid, /* Memory cell that contains the rowid to delete */ 515 int count /* Increment the row change counter */ 516 ){ 517 int addr; 518 Vdbe *v; 519 520 v = pParse->pVdbe; 521 addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid); 522 sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0); 523 sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0)); 524 if( count ){ 525 sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC); 526 } 527 sqlite3VdbeJumpHere(v, addr); 528 } 529 530 /* 531 ** This routine generates VDBE code that causes the deletion of all 532 ** index entries associated with a single row of a single table. 533 ** 534 ** The VDBE must be in a particular state when this routine is called. 535 ** These are the requirements: 536 ** 537 ** 1. A read/write cursor pointing to pTab, the table containing the row 538 ** to be deleted, must be opened as cursor number "iCur". 539 ** 540 ** 2. Read/write cursors for all indices of pTab must be open as 541 ** cursor number iCur+i for the i-th index. 542 ** 543 ** 3. The "iCur" cursor must be pointing to the row that is to be 544 ** deleted. 545 */ 546 void sqlite3GenerateRowIndexDelete( 547 Parse *pParse, /* Parsing and code generating context */ 548 Table *pTab, /* Table containing the row to be deleted */ 549 int iCur, /* Cursor number for the table */ 550 int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */ 551 ){ 552 int i; 553 Index *pIdx; 554 int r1; 555 556 for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ 557 if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue; 558 r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0); 559 sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1); 560 } 561 } 562 563 /* 564 ** Generate code that will assemble an index key and put it in register 565 ** regOut. The key with be for index pIdx which is an index on pTab. 566 ** iCur is the index of a cursor open on the pTab table and pointing to 567 ** the entry that needs indexing. 568 ** 569 ** Return a register number which is the first in a block of 570 ** registers that holds the elements of the index key. The 571 ** block of registers has already been deallocated by the time 572 ** this routine returns. 573 */ 574 int sqlite3GenerateIndexKey( 575 Parse *pParse, /* Parsing context */ 576 Index *pIdx, /* The index for which to generate a key */ 577 int iCur, /* Cursor number for the pIdx->pTable table */ 578 int regOut, /* Write the new index key to this register */ 579 int doMakeRec /* Run the OP_MakeRecord instruction if true */ 580 ){ 581 Vdbe *v = pParse->pVdbe; 582 int j; 583 Table *pTab = pIdx->pTable; 584 int regBase; 585 int nCol; 586 587 nCol = pIdx->nColumn; 588 regBase = sqlite3GetTempRange(pParse, nCol+1); 589 sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol); 590 for(j=0; j<nCol; j++){ 591 int idx = pIdx->aiColumn[j]; 592 if( idx==pTab->iPKey ){ 593 sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j); 594 }else{ 595 sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j); 596 sqlite3ColumnDefault(v, pTab, idx); 597 } 598 } 599 if( doMakeRec ){ 600 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut); 601 sqlite3IndexAffinityStr(v, pIdx); 602 sqlite3ExprCacheAffinityChange(pParse, regBase, nCol+1); 603 } 604 sqlite3ReleaseTempRange(pParse, regBase, nCol+1); 605 return regBase; 606 } 607 608 /* Make sure "isView" gets undefined in case this file becomes part of 609 ** the amalgamation - so that subsequent files do not see isView as a 610 ** macro. */ 611 #undef isView 612