000001 /*
000002 ** 2001 September 15
000003 **
000004 ** The author disclaims copyright to this source code. In place of
000005 ** a legal notice, here is a blessing:
000006 **
000007 ** May you do good and not evil.
000008 ** May you find forgiveness for yourself and forgive others.
000009 ** May you share freely, never taking more than you give.
000010 **
000011 *************************************************************************
000012 ** This file contains C code routines that are called by the parser
000013 ** in order to generate code for DELETE FROM statements.
000014 */
000015 #include "sqliteInt.h"
000016
000017 /*
000018 ** While a SrcList can in general represent multiple tables and subqueries
000019 ** (as in the FROM clause of a SELECT statement) in this case it contains
000020 ** the name of a single table, as one might find in an INSERT, DELETE,
000021 ** or UPDATE statement. Look up that table in the symbol table and
000022 ** return a pointer. Set an error message and return NULL if the table
000023 ** name is not found or if any other error occurs.
000024 **
000025 ** The following fields are initialized appropriate in pSrc:
000026 **
000027 ** pSrc->a[0].pTab Pointer to the Table object
000028 ** pSrc->a[0].pIndex Pointer to the INDEXED BY index, if there is one
000029 **
000030 */
000031 Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){
000032 SrcItem *pItem = pSrc->a;
000033 Table *pTab;
000034 assert( pItem && pSrc->nSrc>=1 );
000035 pTab = sqlite3LocateTableItem(pParse, 0, pItem);
000036 if( pItem->pTab ) sqlite3DeleteTable(pParse->db, pItem->pTab);
000037 pItem->pTab = pTab;
000038 pItem->fg.notCte = 1;
000039 if( pTab ){
000040 pTab->nTabRef++;
000041 if( pItem->fg.isIndexedBy && sqlite3IndexedByLookup(pParse, pItem) ){
000042 pTab = 0;
000043 }
000044 }
000045 return pTab;
000046 }
000047
000048 /* Generate byte-code that will report the number of rows modified
000049 ** by a DELETE, INSERT, or UPDATE statement.
000050 */
000051 void sqlite3CodeChangeCount(Vdbe *v, int regCounter, const char *zColName){
000052 sqlite3VdbeAddOp0(v, OP_FkCheck);
000053 sqlite3VdbeAddOp2(v, OP_ResultRow, regCounter, 1);
000054 sqlite3VdbeSetNumCols(v, 1);
000055 sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zColName, SQLITE_STATIC);
000056 }
000057
000058 /* Return true if table pTab is read-only.
000059 **
000060 ** A table is read-only if any of the following are true:
000061 **
000062 ** 1) It is a virtual table and no implementation of the xUpdate method
000063 ** has been provided
000064 **
000065 ** 2) A trigger is currently being coded and the table is a virtual table
000066 ** that is SQLITE_VTAB_DIRECTONLY or if PRAGMA trusted_schema=OFF and
000067 ** the table is not SQLITE_VTAB_INNOCUOUS.
000068 **
000069 ** 3) It is a system table (i.e. sqlite_schema), this call is not
000070 ** part of a nested parse and writable_schema pragma has not
000071 ** been specified
000072 **
000073 ** 4) The table is a shadow table, the database connection is in
000074 ** defensive mode, and the current sqlite3_prepare()
000075 ** is for a top-level SQL statement.
000076 */
000077 static int vtabIsReadOnly(Parse *pParse, Table *pTab){
000078 if( sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0 ){
000079 return 1;
000080 }
000081
000082 /* Within triggers:
000083 ** * Do not allow DELETE, INSERT, or UPDATE of SQLITE_VTAB_DIRECTONLY
000084 ** virtual tables
000085 ** * Only allow DELETE, INSERT, or UPDATE of non-SQLITE_VTAB_INNOCUOUS
000086 ** virtual tables if PRAGMA trusted_schema=ON.
000087 */
000088 if( pParse->pToplevel!=0
000089 && pTab->u.vtab.p->eVtabRisk >
000090 ((pParse->db->flags & SQLITE_TrustedSchema)!=0)
000091 ){
000092 sqlite3ErrorMsg(pParse, "unsafe use of virtual table \"%s\"",
000093 pTab->zName);
000094 }
000095 return 0;
000096 }
000097 static int tabIsReadOnly(Parse *pParse, Table *pTab){
000098 sqlite3 *db;
000099 if( IsVirtual(pTab) ){
000100 return vtabIsReadOnly(pParse, pTab);
000101 }
000102 if( (pTab->tabFlags & (TF_Readonly|TF_Shadow))==0 ) return 0;
000103 db = pParse->db;
000104 if( (pTab->tabFlags & TF_Readonly)!=0 ){
000105 return sqlite3WritableSchema(db)==0 && pParse->nested==0;
000106 }
000107 assert( pTab->tabFlags & TF_Shadow );
000108 return sqlite3ReadOnlyShadowTables(db);
000109 }
000110
000111 /*
000112 ** Check to make sure the given table is writable.
000113 **
000114 ** If pTab is not writable -> generate an error message and return 1.
000115 ** If pTab is writable but other errors have occurred -> return 1.
000116 ** If pTab is writable and no prior errors -> return 0;
000117 */
000118 int sqlite3IsReadOnly(Parse *pParse, Table *pTab, Trigger *pTrigger){
000119 if( tabIsReadOnly(pParse, pTab) ){
000120 sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
000121 return 1;
000122 }
000123 #ifndef SQLITE_OMIT_VIEW
000124 if( IsView(pTab)
000125 && (pTrigger==0 || (pTrigger->bReturning && pTrigger->pNext==0))
000126 ){
000127 sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
000128 return 1;
000129 }
000130 #endif
000131 return 0;
000132 }
000133
000134
000135 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
000136 /*
000137 ** Evaluate a view and store its result in an ephemeral table. The
000138 ** pWhere argument is an optional WHERE clause that restricts the
000139 ** set of rows in the view that are to be added to the ephemeral table.
000140 */
000141 void sqlite3MaterializeView(
000142 Parse *pParse, /* Parsing context */
000143 Table *pView, /* View definition */
000144 Expr *pWhere, /* Optional WHERE clause to be added */
000145 ExprList *pOrderBy, /* Optional ORDER BY clause */
000146 Expr *pLimit, /* Optional LIMIT clause */
000147 int iCur /* Cursor number for ephemeral table */
000148 ){
000149 SelectDest dest;
000150 Select *pSel;
000151 SrcList *pFrom;
000152 sqlite3 *db = pParse->db;
000153 int iDb = sqlite3SchemaToIndex(db, pView->pSchema);
000154 pWhere = sqlite3ExprDup(db, pWhere, 0);
000155 pFrom = sqlite3SrcListAppend(pParse, 0, 0, 0);
000156 if( pFrom ){
000157 assert( pFrom->nSrc==1 );
000158 pFrom->a[0].zName = sqlite3DbStrDup(db, pView->zName);
000159 pFrom->a[0].zDatabase = sqlite3DbStrDup(db, db->aDb[iDb].zDbSName);
000160 assert( pFrom->a[0].fg.isUsing==0 );
000161 assert( pFrom->a[0].u3.pOn==0 );
000162 }
000163 pSel = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, pOrderBy,
000164 SF_IncludeHidden, pLimit);
000165 sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur);
000166 sqlite3Select(pParse, pSel, &dest);
000167 sqlite3SelectDelete(db, pSel);
000168 }
000169 #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */
000170
000171 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY)
000172 /*
000173 ** Generate an expression tree to implement the WHERE, ORDER BY,
000174 ** and LIMIT/OFFSET portion of DELETE and UPDATE statements.
000175 **
000176 ** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1;
000177 ** \__________________________/
000178 ** pLimitWhere (pInClause)
000179 */
000180 Expr *sqlite3LimitWhere(
000181 Parse *pParse, /* The parser context */
000182 SrcList *pSrc, /* the FROM clause -- which tables to scan */
000183 Expr *pWhere, /* The WHERE clause. May be null */
000184 ExprList *pOrderBy, /* The ORDER BY clause. May be null */
000185 Expr *pLimit, /* The LIMIT clause. May be null */
000186 char *zStmtType /* Either DELETE or UPDATE. For err msgs. */
000187 ){
000188 sqlite3 *db = pParse->db;
000189 Expr *pLhs = NULL; /* LHS of IN(SELECT...) operator */
000190 Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */
000191 ExprList *pEList = NULL; /* Expression list containing only pSelectRowid*/
000192 SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */
000193 Select *pSelect = NULL; /* Complete SELECT tree */
000194 Table *pTab;
000195
000196 /* Check that there isn't an ORDER BY without a LIMIT clause.
000197 */
000198 if( pOrderBy && pLimit==0 ) {
000199 sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType);
000200 sqlite3ExprDelete(pParse->db, pWhere);
000201 sqlite3ExprListDelete(pParse->db, pOrderBy);
000202 return 0;
000203 }
000204
000205 /* We only need to generate a select expression if there
000206 ** is a limit/offset term to enforce.
000207 */
000208 if( pLimit == 0 ) {
000209 return pWhere;
000210 }
000211
000212 /* Generate a select expression tree to enforce the limit/offset
000213 ** term for the DELETE or UPDATE statement. For example:
000214 ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
000215 ** becomes:
000216 ** DELETE FROM table_a WHERE rowid IN (
000217 ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1
000218 ** );
000219 */
000220
000221 pTab = pSrc->a[0].pTab;
000222 if( HasRowid(pTab) ){
000223 pLhs = sqlite3PExpr(pParse, TK_ROW, 0, 0);
000224 pEList = sqlite3ExprListAppend(
000225 pParse, 0, sqlite3PExpr(pParse, TK_ROW, 0, 0)
000226 );
000227 }else{
000228 Index *pPk = sqlite3PrimaryKeyIndex(pTab);
000229 assert( pPk!=0 );
000230 assert( pPk->nKeyCol>=1 );
000231 if( pPk->nKeyCol==1 ){
000232 const char *zName;
000233 assert( pPk->aiColumn[0]>=0 && pPk->aiColumn[0]<pTab->nCol );
000234 zName = pTab->aCol[pPk->aiColumn[0]].zCnName;
000235 pLhs = sqlite3Expr(db, TK_ID, zName);
000236 pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, zName));
000237 }else{
000238 int i;
000239 for(i=0; i<pPk->nKeyCol; i++){
000240 Expr *p;
000241 assert( pPk->aiColumn[i]>=0 && pPk->aiColumn[i]<pTab->nCol );
000242 p = sqlite3Expr(db, TK_ID, pTab->aCol[pPk->aiColumn[i]].zCnName);
000243 pEList = sqlite3ExprListAppend(pParse, pEList, p);
000244 }
000245 pLhs = sqlite3PExpr(pParse, TK_VECTOR, 0, 0);
000246 if( pLhs ){
000247 pLhs->x.pList = sqlite3ExprListDup(db, pEList, 0);
000248 }
000249 }
000250 }
000251
000252 /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree
000253 ** and the SELECT subtree. */
000254 pSrc->a[0].pTab = 0;
000255 pSelectSrc = sqlite3SrcListDup(db, pSrc, 0);
000256 pSrc->a[0].pTab = pTab;
000257 if( pSrc->a[0].fg.isIndexedBy ){
000258 assert( pSrc->a[0].fg.isCte==0 );
000259 pSrc->a[0].u2.pIBIndex = 0;
000260 pSrc->a[0].fg.isIndexedBy = 0;
000261 sqlite3DbFree(db, pSrc->a[0].u1.zIndexedBy);
000262 }else if( pSrc->a[0].fg.isCte ){
000263 pSrc->a[0].u2.pCteUse->nUse++;
000264 }
000265
000266 /* generate the SELECT expression tree. */
000267 pSelect = sqlite3SelectNew(pParse, pEList, pSelectSrc, pWhere, 0 ,0,
000268 pOrderBy,0,pLimit
000269 );
000270
000271 /* now generate the new WHERE rowid IN clause for the DELETE/UPDATE */
000272 pInClause = sqlite3PExpr(pParse, TK_IN, pLhs, 0);
000273 sqlite3PExprAddSelect(pParse, pInClause, pSelect);
000274 return pInClause;
000275 }
000276 #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) */
000277 /* && !defined(SQLITE_OMIT_SUBQUERY) */
000278
000279 /*
000280 ** Generate code for a DELETE FROM statement.
000281 **
000282 ** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
000283 ** \________/ \________________/
000284 ** pTabList pWhere
000285 */
000286 void sqlite3DeleteFrom(
000287 Parse *pParse, /* The parser context */
000288 SrcList *pTabList, /* The table from which we should delete things */
000289 Expr *pWhere, /* The WHERE clause. May be null */
000290 ExprList *pOrderBy, /* ORDER BY clause. May be null */
000291 Expr *pLimit /* LIMIT clause. May be null */
000292 ){
000293 Vdbe *v; /* The virtual database engine */
000294 Table *pTab; /* The table from which records will be deleted */
000295 int i; /* Loop counter */
000296 WhereInfo *pWInfo; /* Information about the WHERE clause */
000297 Index *pIdx; /* For looping over indices of the table */
000298 int iTabCur; /* Cursor number for the table */
000299 int iDataCur = 0; /* VDBE cursor for the canonical data source */
000300 int iIdxCur = 0; /* Cursor number of the first index */
000301 int nIdx; /* Number of indices */
000302 sqlite3 *db; /* Main database structure */
000303 AuthContext sContext; /* Authorization context */
000304 NameContext sNC; /* Name context to resolve expressions in */
000305 int iDb; /* Database number */
000306 int memCnt = 0; /* Memory cell used for change counting */
000307 int rcauth; /* Value returned by authorization callback */
000308 int eOnePass; /* ONEPASS_OFF or _SINGLE or _MULTI */
000309 int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */
000310 u8 *aToOpen = 0; /* Open cursor iTabCur+j if aToOpen[j] is true */
000311 Index *pPk; /* The PRIMARY KEY index on the table */
000312 int iPk = 0; /* First of nPk registers holding PRIMARY KEY value */
000313 i16 nPk = 1; /* Number of columns in the PRIMARY KEY */
000314 int iKey; /* Memory cell holding key of row to be deleted */
000315 i16 nKey; /* Number of memory cells in the row key */
000316 int iEphCur = 0; /* Ephemeral table holding all primary key values */
000317 int iRowSet = 0; /* Register for rowset of rows to delete */
000318 int addrBypass = 0; /* Address of jump over the delete logic */
000319 int addrLoop = 0; /* Top of the delete loop */
000320 int addrEphOpen = 0; /* Instruction to open the Ephemeral table */
000321 int bComplex; /* True if there are triggers or FKs or
000322 ** subqueries in the WHERE clause */
000323
000324 #ifndef SQLITE_OMIT_TRIGGER
000325 int isView; /* True if attempting to delete from a view */
000326 Trigger *pTrigger; /* List of table triggers, if required */
000327 #endif
000328
000329 memset(&sContext, 0, sizeof(sContext));
000330 db = pParse->db;
000331 assert( db->pParse==pParse );
000332 if( pParse->nErr ){
000333 goto delete_from_cleanup;
000334 }
000335 assert( db->mallocFailed==0 );
000336 assert( pTabList->nSrc==1 );
000337
000338 /* Locate the table which we want to delete. This table has to be
000339 ** put in an SrcList structure because some of the subroutines we
000340 ** will be calling are designed to work with multiple tables and expect
000341 ** an SrcList* parameter instead of just a Table* parameter.
000342 */
000343 pTab = sqlite3SrcListLookup(pParse, pTabList);
000344 if( pTab==0 ) goto delete_from_cleanup;
000345
000346 /* Figure out if we have any triggers and if the table being
000347 ** deleted from is a view
000348 */
000349 #ifndef SQLITE_OMIT_TRIGGER
000350 pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0);
000351 isView = IsView(pTab);
000352 #else
000353 # define pTrigger 0
000354 # define isView 0
000355 #endif
000356 bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 0);
000357 #ifdef SQLITE_OMIT_VIEW
000358 # undef isView
000359 # define isView 0
000360 #endif
000361
000362 #if TREETRACE_ENABLED
000363 if( sqlite3TreeTrace & 0x10000 ){
000364 sqlite3TreeViewLine(0, "In sqlite3Delete() at %s:%d", __FILE__, __LINE__);
000365 sqlite3TreeViewDelete(pParse->pWith, pTabList, pWhere,
000366 pOrderBy, pLimit, pTrigger);
000367 }
000368 #endif
000369
000370 #ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT
000371 if( !isView ){
000372 pWhere = sqlite3LimitWhere(
000373 pParse, pTabList, pWhere, pOrderBy, pLimit, "DELETE"
000374 );
000375 pOrderBy = 0;
000376 pLimit = 0;
000377 }
000378 #endif
000379
000380 /* If pTab is really a view, make sure it has been initialized.
000381 */
000382 if( sqlite3ViewGetColumnNames(pParse, pTab) ){
000383 goto delete_from_cleanup;
000384 }
000385
000386 if( sqlite3IsReadOnly(pParse, pTab, pTrigger) ){
000387 goto delete_from_cleanup;
000388 }
000389 iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
000390 assert( iDb<db->nDb );
000391 rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0,
000392 db->aDb[iDb].zDbSName);
000393 assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE );
000394 if( rcauth==SQLITE_DENY ){
000395 goto delete_from_cleanup;
000396 }
000397 assert(!isView || pTrigger);
000398
000399 /* Assign cursor numbers to the table and all its indices.
000400 */
000401 assert( pTabList->nSrc==1 );
000402 iTabCur = pTabList->a[0].iCursor = pParse->nTab++;
000403 for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){
000404 pParse->nTab++;
000405 }
000406
000407 /* Start the view context
000408 */
000409 if( isView ){
000410 sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
000411 }
000412
000413 /* Begin generating code.
000414 */
000415 v = sqlite3GetVdbe(pParse);
000416 if( v==0 ){
000417 goto delete_from_cleanup;
000418 }
000419 if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
000420 sqlite3BeginWriteOperation(pParse, bComplex, iDb);
000421
000422 /* If we are trying to delete from a view, realize that view into
000423 ** an ephemeral table.
000424 */
000425 #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
000426 if( isView ){
000427 sqlite3MaterializeView(pParse, pTab,
000428 pWhere, pOrderBy, pLimit, iTabCur
000429 );
000430 iDataCur = iIdxCur = iTabCur;
000431 pOrderBy = 0;
000432 pLimit = 0;
000433 }
000434 #endif
000435
000436 /* Resolve the column names in the WHERE clause.
000437 */
000438 memset(&sNC, 0, sizeof(sNC));
000439 sNC.pParse = pParse;
000440 sNC.pSrcList = pTabList;
000441 if( sqlite3ResolveExprNames(&sNC, pWhere) ){
000442 goto delete_from_cleanup;
000443 }
000444
000445 /* Initialize the counter of the number of rows deleted, if
000446 ** we are counting rows.
000447 */
000448 if( (db->flags & SQLITE_CountRows)!=0
000449 && !pParse->nested
000450 && !pParse->pTriggerTab
000451 && !pParse->bReturning
000452 ){
000453 memCnt = ++pParse->nMem;
000454 sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt);
000455 }
000456
000457 #ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION
000458 /* Special case: A DELETE without a WHERE clause deletes everything.
000459 ** It is easier just to erase the whole table. Prior to version 3.6.5,
000460 ** this optimization caused the row change count (the value returned by
000461 ** API function sqlite3_count_changes) to be set incorrectly.
000462 **
000463 ** The "rcauth==SQLITE_OK" terms is the
000464 ** IMPLEMENTATION-OF: R-17228-37124 If the action code is SQLITE_DELETE and
000465 ** the callback returns SQLITE_IGNORE then the DELETE operation proceeds but
000466 ** the truncate optimization is disabled and all rows are deleted
000467 ** individually.
000468 */
000469 if( rcauth==SQLITE_OK
000470 && pWhere==0
000471 && !bComplex
000472 && !IsVirtual(pTab)
000473 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
000474 && db->xPreUpdateCallback==0
000475 #endif
000476 ){
000477 assert( !isView );
000478 sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
000479 if( HasRowid(pTab) ){
000480 sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt ? memCnt : -1,
000481 pTab->zName, P4_STATIC);
000482 }
000483 for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
000484 assert( pIdx->pSchema==pTab->pSchema );
000485 if( IsPrimaryKeyIndex(pIdx) && !HasRowid(pTab) ){
000486 sqlite3VdbeAddOp3(v, OP_Clear, pIdx->tnum, iDb, memCnt ? memCnt : -1);
000487 }else{
000488 sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
000489 }
000490 }
000491 }else
000492 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
000493 {
000494 u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
000495 if( sNC.ncFlags & NC_Subquery ) bComplex = 1;
000496 wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
000497 if( HasRowid(pTab) ){
000498 /* For a rowid table, initialize the RowSet to an empty set */
000499 pPk = 0;
000500 assert( nPk==1 );
000501 iRowSet = ++pParse->nMem;
000502 sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet);
000503 }else{
000504 /* For a WITHOUT ROWID table, create an ephemeral table used to
000505 ** hold all primary keys for rows to be deleted. */
000506 pPk = sqlite3PrimaryKeyIndex(pTab);
000507 assert( pPk!=0 );
000508 nPk = pPk->nKeyCol;
000509 iPk = pParse->nMem+1;
000510 pParse->nMem += nPk;
000511 iEphCur = pParse->nTab++;
000512 addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk);
000513 sqlite3VdbeSetP4KeyInfo(pParse, pPk);
000514 }
000515
000516 /* Construct a query to find the rowid or primary key for every row
000517 ** to be deleted, based on the WHERE clause. Set variable eOnePass
000518 ** to indicate the strategy used to implement this delete:
000519 **
000520 ** ONEPASS_OFF: Two-pass approach - use a FIFO for rowids/PK values.
000521 ** ONEPASS_SINGLE: One-pass approach - at most one row deleted.
000522 ** ONEPASS_MULTI: One-pass approach - any number of rows may be deleted.
000523 */
000524 pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0,0,wcf,iTabCur+1);
000525 if( pWInfo==0 ) goto delete_from_cleanup;
000526 eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass);
000527 assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
000528 assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF
000529 || OptimizationDisabled(db, SQLITE_OnePass) );
000530 if( eOnePass!=ONEPASS_SINGLE ) sqlite3MultiWrite(pParse);
000531 if( sqlite3WhereUsesDeferredSeek(pWInfo) ){
000532 sqlite3VdbeAddOp1(v, OP_FinishSeek, iTabCur);
000533 }
000534
000535 /* Keep track of the number of rows to be deleted */
000536 if( memCnt ){
000537 sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1);
000538 }
000539
000540 /* Extract the rowid or primary key for the current row */
000541 if( pPk ){
000542 for(i=0; i<nPk; i++){
000543 assert( pPk->aiColumn[i]>=0 );
000544 sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur,
000545 pPk->aiColumn[i], iPk+i);
000546 }
000547 iKey = iPk;
000548 }else{
000549 iKey = ++pParse->nMem;
000550 sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, -1, iKey);
000551 }
000552
000553 if( eOnePass!=ONEPASS_OFF ){
000554 /* For ONEPASS, no need to store the rowid/primary-key. There is only
000555 ** one, so just keep it in its register(s) and fall through to the
000556 ** delete code. */
000557 nKey = nPk; /* OP_Found will use an unpacked key */
000558 aToOpen = sqlite3DbMallocRawNN(db, nIdx+2);
000559 if( aToOpen==0 ){
000560 sqlite3WhereEnd(pWInfo);
000561 goto delete_from_cleanup;
000562 }
000563 memset(aToOpen, 1, nIdx+1);
000564 aToOpen[nIdx+1] = 0;
000565 if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
000566 if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
000567 if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
000568 addrBypass = sqlite3VdbeMakeLabel(pParse);
000569 }else{
000570 if( pPk ){
000571 /* Add the PK key for this row to the temporary table */
000572 iKey = ++pParse->nMem;
000573 nKey = 0; /* Zero tells OP_Found to use a composite key */
000574 sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey,
000575 sqlite3IndexAffinityStr(pParse->db, pPk), nPk);
000576 sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEphCur, iKey, iPk, nPk);
000577 }else{
000578 /* Add the rowid of the row to be deleted to the RowSet */
000579 nKey = 1; /* OP_DeferredSeek always uses a single rowid */
000580 sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
000581 }
000582 sqlite3WhereEnd(pWInfo);
000583 }
000584
000585 /* Unless this is a view, open cursors for the table we are
000586 ** deleting from and all its indices. If this is a view, then the
000587 ** only effect this statement has is to fire the INSTEAD OF
000588 ** triggers.
000589 */
000590 if( !isView ){
000591 int iAddrOnce = 0;
000592 if( eOnePass==ONEPASS_MULTI ){
000593 iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
000594 }
000595 testcase( IsVirtual(pTab) );
000596 sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE,
000597 iTabCur, aToOpen, &iDataCur, &iIdxCur);
000598 assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur );
000599 assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 );
000600 if( eOnePass==ONEPASS_MULTI ){
000601 sqlite3VdbeJumpHereOrPopInst(v, iAddrOnce);
000602 }
000603 }
000604
000605 /* Set up a loop over the rowids/primary-keys that were found in the
000606 ** where-clause loop above.
000607 */
000608 if( eOnePass!=ONEPASS_OFF ){
000609 assert( nKey==nPk ); /* OP_Found will use an unpacked key */
000610 if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){
000611 assert( pPk!=0 || IsView(pTab) );
000612 sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey);
000613 VdbeCoverage(v);
000614 }
000615 }else if( pPk ){
000616 addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v);
000617 if( IsVirtual(pTab) ){
000618 sqlite3VdbeAddOp3(v, OP_Column, iEphCur, 0, iKey);
000619 }else{
000620 sqlite3VdbeAddOp2(v, OP_RowData, iEphCur, iKey);
000621 }
000622 assert( nKey==0 ); /* OP_Found will use a composite key */
000623 }else{
000624 addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey);
000625 VdbeCoverage(v);
000626 assert( nKey==1 );
000627 }
000628
000629 /* Delete the row */
000630 #ifndef SQLITE_OMIT_VIRTUALTABLE
000631 if( IsVirtual(pTab) ){
000632 const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
000633 sqlite3VtabMakeWritable(pParse, pTab);
000634 assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE );
000635 sqlite3MayAbort(pParse);
000636 if( eOnePass==ONEPASS_SINGLE ){
000637 sqlite3VdbeAddOp1(v, OP_Close, iTabCur);
000638 if( sqlite3IsToplevel(pParse) ){
000639 pParse->isMultiWrite = 0;
000640 }
000641 }
000642 sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iKey, pVTab, P4_VTAB);
000643 sqlite3VdbeChangeP5(v, OE_Abort);
000644 }else
000645 #endif
000646 {
000647 int count = (pParse->nested==0); /* True to count changes */
000648 sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
000649 iKey, nKey, count, OE_Default, eOnePass, aiCurOnePass[1]);
000650 }
000651
000652 /* End of the loop over all rowids/primary-keys. */
000653 if( eOnePass!=ONEPASS_OFF ){
000654 sqlite3VdbeResolveLabel(v, addrBypass);
000655 sqlite3WhereEnd(pWInfo);
000656 }else if( pPk ){
000657 sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v);
000658 sqlite3VdbeJumpHere(v, addrLoop);
000659 }else{
000660 sqlite3VdbeGoto(v, addrLoop);
000661 sqlite3VdbeJumpHere(v, addrLoop);
000662 }
000663 } /* End non-truncate path */
000664
000665 /* Update the sqlite_sequence table by storing the content of the
000666 ** maximum rowid counter values recorded while inserting into
000667 ** autoincrement tables.
000668 */
000669 if( pParse->nested==0 && pParse->pTriggerTab==0 ){
000670 sqlite3AutoincrementEnd(pParse);
000671 }
000672
000673 /* Return the number of rows that were deleted. If this routine is
000674 ** generating code because of a call to sqlite3NestedParse(), do not
000675 ** invoke the callback function.
000676 */
000677 if( memCnt ){
000678 sqlite3CodeChangeCount(v, memCnt, "rows deleted");
000679 }
000680
000681 delete_from_cleanup:
000682 sqlite3AuthContextPop(&sContext);
000683 sqlite3SrcListDelete(db, pTabList);
000684 sqlite3ExprDelete(db, pWhere);
000685 #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT)
000686 sqlite3ExprListDelete(db, pOrderBy);
000687 sqlite3ExprDelete(db, pLimit);
000688 #endif
000689 if( aToOpen ) sqlite3DbNNFreeNN(db, aToOpen);
000690 return;
000691 }
000692 /* Make sure "isView" and other macros defined above are undefined. Otherwise
000693 ** they may interfere with compilation of other functions in this file
000694 ** (or in another file, if this file becomes part of the amalgamation). */
000695 #ifdef isView
000696 #undef isView
000697 #endif
000698 #ifdef pTrigger
000699 #undef pTrigger
000700 #endif
000701
000702 /*
000703 ** This routine generates VDBE code that causes a single row of a
000704 ** single table to be deleted. Both the original table entry and
000705 ** all indices are removed.
000706 **
000707 ** Preconditions:
000708 **
000709 ** 1. iDataCur is an open cursor on the btree that is the canonical data
000710 ** store for the table. (This will be either the table itself,
000711 ** in the case of a rowid table, or the PRIMARY KEY index in the case
000712 ** of a WITHOUT ROWID table.)
000713 **
000714 ** 2. Read/write cursors for all indices of pTab must be open as
000715 ** cursor number iIdxCur+i for the i-th index.
000716 **
000717 ** 3. The primary key for the row to be deleted must be stored in a
000718 ** sequence of nPk memory cells starting at iPk. If nPk==0 that means
000719 ** that a search record formed from OP_MakeRecord is contained in the
000720 ** single memory location iPk.
000721 **
000722 ** eMode:
000723 ** Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or
000724 ** ONEPASS_MULTI. If eMode is not ONEPASS_OFF, then the cursor
000725 ** iDataCur already points to the row to delete. If eMode is ONEPASS_OFF
000726 ** then this function must seek iDataCur to the entry identified by iPk
000727 ** and nPk before reading from it.
000728 **
000729 ** If eMode is ONEPASS_MULTI, then this call is being made as part
000730 ** of a ONEPASS delete that affects multiple rows. In this case, if
000731 ** iIdxNoSeek is a valid cursor number (>=0) and is not the same as
000732 ** iDataCur, then its position should be preserved following the delete
000733 ** operation. Or, if iIdxNoSeek is not a valid cursor number, the
000734 ** position of iDataCur should be preserved instead.
000735 **
000736 ** iIdxNoSeek:
000737 ** If iIdxNoSeek is a valid cursor number (>=0) not equal to iDataCur,
000738 ** then it identifies an index cursor (from within array of cursors
000739 ** starting at iIdxCur) that already points to the index entry to be deleted.
000740 ** Except, this optimization is disabled if there are BEFORE triggers since
000741 ** the trigger body might have moved the cursor.
000742 */
000743 void sqlite3GenerateRowDelete(
000744 Parse *pParse, /* Parsing context */
000745 Table *pTab, /* Table containing the row to be deleted */
000746 Trigger *pTrigger, /* List of triggers to (potentially) fire */
000747 int iDataCur, /* Cursor from which column data is extracted */
000748 int iIdxCur, /* First index cursor */
000749 int iPk, /* First memory cell containing the PRIMARY KEY */
000750 i16 nPk, /* Number of PRIMARY KEY memory cells */
000751 u8 count, /* If non-zero, increment the row change counter */
000752 u8 onconf, /* Default ON CONFLICT policy for triggers */
000753 u8 eMode, /* ONEPASS_OFF, _SINGLE, or _MULTI. See above */
000754 int iIdxNoSeek /* Cursor number of cursor that does not need seeking */
000755 ){
000756 Vdbe *v = pParse->pVdbe; /* Vdbe */
000757 int iOld = 0; /* First register in OLD.* array */
000758 int iLabel; /* Label resolved to end of generated code */
000759 u8 opSeek; /* Seek opcode */
000760
000761 /* Vdbe is guaranteed to have been allocated by this stage. */
000762 assert( v );
000763 VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)",
000764 iDataCur, iIdxCur, iPk, (int)nPk));
000765
000766 /* Seek cursor iCur to the row to delete. If this row no longer exists
000767 ** (this can happen if a trigger program has already deleted it), do
000768 ** not attempt to delete it or fire any DELETE triggers. */
000769 iLabel = sqlite3VdbeMakeLabel(pParse);
000770 opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound;
000771 if( eMode==ONEPASS_OFF ){
000772 sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
000773 VdbeCoverageIf(v, opSeek==OP_NotExists);
000774 VdbeCoverageIf(v, opSeek==OP_NotFound);
000775 }
000776
000777 /* If there are any triggers to fire, allocate a range of registers to
000778 ** use for the old.* references in the triggers. */
000779 if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){
000780 u32 mask; /* Mask of OLD.* columns in use */
000781 int iCol; /* Iterator used while populating OLD.* */
000782 int addrStart; /* Start of BEFORE trigger programs */
000783
000784 /* TODO: Could use temporary registers here. Also could attempt to
000785 ** avoid copying the contents of the rowid register. */
000786 mask = sqlite3TriggerColmask(
000787 pParse, pTrigger, 0, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onconf
000788 );
000789 mask |= sqlite3FkOldmask(pParse, pTab);
000790 iOld = pParse->nMem+1;
000791 pParse->nMem += (1 + pTab->nCol);
000792
000793 /* Populate the OLD.* pseudo-table register array. These values will be
000794 ** used by any BEFORE and AFTER triggers that exist. */
000795 sqlite3VdbeAddOp2(v, OP_Copy, iPk, iOld);
000796 for(iCol=0; iCol<pTab->nCol; iCol++){
000797 testcase( mask!=0xffffffff && iCol==31 );
000798 testcase( mask!=0xffffffff && iCol==32 );
000799 if( mask==0xffffffff || (iCol<=31 && (mask & MASKBIT32(iCol))!=0) ){
000800 int kk = sqlite3TableColumnToStorage(pTab, iCol);
000801 sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+kk+1);
000802 }
000803 }
000804
000805 /* Invoke BEFORE DELETE trigger programs. */
000806 addrStart = sqlite3VdbeCurrentAddr(v);
000807 sqlite3CodeRowTrigger(pParse, pTrigger,
000808 TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel
000809 );
000810
000811 /* If any BEFORE triggers were coded, then seek the cursor to the
000812 ** row to be deleted again. It may be that the BEFORE triggers moved
000813 ** the cursor or already deleted the row that the cursor was
000814 ** pointing to.
000815 **
000816 ** Also disable the iIdxNoSeek optimization since the BEFORE trigger
000817 ** may have moved that cursor.
000818 */
000819 if( addrStart<sqlite3VdbeCurrentAddr(v) ){
000820 sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk);
000821 VdbeCoverageIf(v, opSeek==OP_NotExists);
000822 VdbeCoverageIf(v, opSeek==OP_NotFound);
000823 testcase( iIdxNoSeek>=0 );
000824 iIdxNoSeek = -1;
000825 }
000826
000827 /* Do FK processing. This call checks that any FK constraints that
000828 ** refer to this table (i.e. constraints attached to other tables)
000829 ** are not violated by deleting this row. */
000830 sqlite3FkCheck(pParse, pTab, iOld, 0, 0, 0);
000831 }
000832
000833 /* Delete the index and table entries. Skip this step if pTab is really
000834 ** a view (in which case the only effect of the DELETE statement is to
000835 ** fire the INSTEAD OF triggers).
000836 **
000837 ** If variable 'count' is non-zero, then this OP_Delete instruction should
000838 ** invoke the update-hook. The pre-update-hook, on the other hand should
000839 ** be invoked unless table pTab is a system table. The difference is that
000840 ** the update-hook is not invoked for rows removed by REPLACE, but the
000841 ** pre-update-hook is.
000842 */
000843 if( !IsView(pTab) ){
000844 u8 p5 = 0;
000845 sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek);
000846 sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
000847 if( pParse->nested==0 || 0==sqlite3_stricmp(pTab->zName, "sqlite_stat1") ){
000848 sqlite3VdbeAppendP4(v, (char*)pTab, P4_TABLE);
000849 }
000850 if( eMode!=ONEPASS_OFF ){
000851 sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE);
000852 }
000853 if( iIdxNoSeek>=0 && iIdxNoSeek!=iDataCur ){
000854 sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek);
000855 }
000856 if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION;
000857 sqlite3VdbeChangeP5(v, p5);
000858 }
000859
000860 /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to
000861 ** handle rows (possibly in other tables) that refer via a foreign key
000862 ** to the row just deleted. */
000863 sqlite3FkActions(pParse, pTab, 0, iOld, 0, 0);
000864
000865 /* Invoke AFTER DELETE trigger programs. */
000866 if( pTrigger ){
000867 sqlite3CodeRowTrigger(pParse, pTrigger,
000868 TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel
000869 );
000870 }
000871
000872 /* Jump here if the row had already been deleted before any BEFORE
000873 ** trigger programs were invoked. Or if a trigger program throws a
000874 ** RAISE(IGNORE) exception. */
000875 sqlite3VdbeResolveLabel(v, iLabel);
000876 VdbeModuleComment((v, "END: GenRowDel()"));
000877 }
000878
000879 /*
000880 ** This routine generates VDBE code that causes the deletion of all
000881 ** index entries associated with a single row of a single table, pTab
000882 **
000883 ** Preconditions:
000884 **
000885 ** 1. A read/write cursor "iDataCur" must be open on the canonical storage
000886 ** btree for the table pTab. (This will be either the table itself
000887 ** for rowid tables or to the primary key index for WITHOUT ROWID
000888 ** tables.)
000889 **
000890 ** 2. Read/write cursors for all indices of pTab must be open as
000891 ** cursor number iIdxCur+i for the i-th index. (The pTab->pIndex
000892 ** index is the 0-th index.)
000893 **
000894 ** 3. The "iDataCur" cursor must be already be positioned on the row
000895 ** that is to be deleted.
000896 */
000897 void sqlite3GenerateRowIndexDelete(
000898 Parse *pParse, /* Parsing and code generating context */
000899 Table *pTab, /* Table containing the row to be deleted */
000900 int iDataCur, /* Cursor of table holding data. */
000901 int iIdxCur, /* First index cursor */
000902 int *aRegIdx, /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
000903 int iIdxNoSeek /* Do not delete from this cursor */
000904 ){
000905 int i; /* Index loop counter */
000906 int r1 = -1; /* Register holding an index key */
000907 int iPartIdxLabel; /* Jump destination for skipping partial index entries */
000908 Index *pIdx; /* Current index */
000909 Index *pPrior = 0; /* Prior index */
000910 Vdbe *v; /* The prepared statement under construction */
000911 Index *pPk; /* PRIMARY KEY index, or NULL for rowid tables */
000912
000913 v = pParse->pVdbe;
000914 pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab);
000915 for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
000916 assert( iIdxCur+i!=iDataCur || pPk==pIdx );
000917 if( aRegIdx!=0 && aRegIdx[i]==0 ) continue;
000918 if( pIdx==pPk ) continue;
000919 if( iIdxCur+i==iIdxNoSeek ) continue;
000920 VdbeModuleComment((v, "GenRowIdxDel for %s", pIdx->zName));
000921 r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 1,
000922 &iPartIdxLabel, pPrior, r1);
000923 sqlite3VdbeAddOp3(v, OP_IdxDelete, iIdxCur+i, r1,
000924 pIdx->uniqNotNull ? pIdx->nKeyCol : pIdx->nColumn);
000925 sqlite3VdbeChangeP5(v, 1); /* Cause IdxDelete to error if no entry found */
000926 sqlite3ResolvePartIdxLabel(pParse, iPartIdxLabel);
000927 pPrior = pIdx;
000928 }
000929 }
000930
000931 /*
000932 ** Generate code that will assemble an index key and stores it in register
000933 ** regOut. The key with be for index pIdx which is an index on pTab.
000934 ** iCur is the index of a cursor open on the pTab table and pointing to
000935 ** the entry that needs indexing. If pTab is a WITHOUT ROWID table, then
000936 ** iCur must be the cursor of the PRIMARY KEY index.
000937 **
000938 ** Return a register number which is the first in a block of
000939 ** registers that holds the elements of the index key. The
000940 ** block of registers has already been deallocated by the time
000941 ** this routine returns.
000942 **
000943 ** If *piPartIdxLabel is not NULL, fill it in with a label and jump
000944 ** to that label if pIdx is a partial index that should be skipped.
000945 ** The label should be resolved using sqlite3ResolvePartIdxLabel().
000946 ** A partial index should be skipped if its WHERE clause evaluates
000947 ** to false or null. If pIdx is not a partial index, *piPartIdxLabel
000948 ** will be set to zero which is an empty label that is ignored by
000949 ** sqlite3ResolvePartIdxLabel().
000950 **
000951 ** The pPrior and regPrior parameters are used to implement a cache to
000952 ** avoid unnecessary register loads. If pPrior is not NULL, then it is
000953 ** a pointer to a different index for which an index key has just been
000954 ** computed into register regPrior. If the current pIdx index is generating
000955 ** its key into the same sequence of registers and if pPrior and pIdx share
000956 ** a column in common, then the register corresponding to that column already
000957 ** holds the correct value and the loading of that register is skipped.
000958 ** This optimization is helpful when doing a DELETE or an INTEGRITY_CHECK
000959 ** on a table with multiple indices, and especially with the ROWID or
000960 ** PRIMARY KEY columns of the index.
000961 */
000962 int sqlite3GenerateIndexKey(
000963 Parse *pParse, /* Parsing context */
000964 Index *pIdx, /* The index for which to generate a key */
000965 int iDataCur, /* Cursor number from which to take column data */
000966 int regOut, /* Put the new key into this register if not 0 */
000967 int prefixOnly, /* Compute only a unique prefix of the key */
000968 int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */
000969 Index *pPrior, /* Previously generated index key */
000970 int regPrior /* Register holding previous generated key */
000971 ){
000972 Vdbe *v = pParse->pVdbe;
000973 int j;
000974 int regBase;
000975 int nCol;
000976
000977 if( piPartIdxLabel ){
000978 if( pIdx->pPartIdxWhere ){
000979 *piPartIdxLabel = sqlite3VdbeMakeLabel(pParse);
000980 pParse->iSelfTab = iDataCur + 1;
000981 sqlite3ExprIfFalseDup(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel,
000982 SQLITE_JUMPIFNULL);
000983 pParse->iSelfTab = 0;
000984 pPrior = 0; /* Ticket a9efb42811fa41ee 2019-11-02;
000985 ** pPartIdxWhere may have corrupted regPrior registers */
000986 }else{
000987 *piPartIdxLabel = 0;
000988 }
000989 }
000990 nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn;
000991 regBase = sqlite3GetTempRange(pParse, nCol);
000992 if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0;
000993 for(j=0; j<nCol; j++){
000994 if( pPrior
000995 && pPrior->aiColumn[j]==pIdx->aiColumn[j]
000996 && pPrior->aiColumn[j]!=XN_EXPR
000997 ){
000998 /* This column was already computed by the previous index */
000999 continue;
001000 }
001001 sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iDataCur, j, regBase+j);
001002 if( pIdx->aiColumn[j]>=0 ){
001003 /* If the column affinity is REAL but the number is an integer, then it
001004 ** might be stored in the table as an integer (using a compact
001005 ** representation) then converted to REAL by an OP_RealAffinity opcode.
001006 ** But we are getting ready to store this value back into an index, where
001007 ** it should be converted by to INTEGER again. So omit the
001008 ** OP_RealAffinity opcode if it is present */
001009 sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity);
001010 }
001011 }
001012 if( regOut ){
001013 sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);
001014 }
001015 sqlite3ReleaseTempRange(pParse, regBase, nCol);
001016 return regBase;
001017 }
001018
001019 /*
001020 ** If a prior call to sqlite3GenerateIndexKey() generated a jump-over label
001021 ** because it was a partial index, then this routine should be called to
001022 ** resolve that label.
001023 */
001024 void sqlite3ResolvePartIdxLabel(Parse *pParse, int iLabel){
001025 if( iLabel ){
001026 sqlite3VdbeResolveLabel(pParse->pVdbe, iLabel);
001027 }
001028 }