/* ** 2001 September 15 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains C code routines that are called by the parser ** in order to generate code for DELETE FROM statements. */ #include "sqliteInt.h" /* ** While a SrcList can in general represent multiple tables and subqueries ** (as in the FROM clause of a SELECT statement) in this case it contains ** the name of a single table, as one might find in an INSERT, DELETE, ** or UPDATE statement. Look up that table in the symbol table and ** return a pointer. Set an error message and return NULL if the table ** name is not found or if any other error occurs. ** ** The following fields are initialized appropriate in pSrc: ** ** pSrc->a[0].pTab Pointer to the Table object ** pSrc->a[0].pIndex Pointer to the INDEXED BY index, if there is one ** */ Table *sqlite3SrcListLookup(Parse *pParse, SrcList *pSrc){ struct SrcList_item *pItem = pSrc->a; Table *pTab; assert( pItem && pSrc->nSrc==1 ); pTab = sqlite3LocateTable(pParse, 0, pItem->zName, pItem->zDatabase); sqlite3DeleteTable(pParse->db, pItem->pTab); pItem->pTab = pTab; if( pTab ){ pTab->nRef++; } if( sqlite3IndexedByLookup(pParse, pItem) ){ pTab = 0; } return pTab; } /* ** Check to make sure the given table is writable. If it is not ** writable, generate an error message and return 1. If it is ** writable return 0; */ int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){ /* A table is not writable under the following circumstances: ** ** 1) It is a virtual table and no implementation of the xUpdate method ** has been provided, or ** 2) It is a system table (i.e. sqlite_master), this call is not ** part of a nested parse and writable_schema pragma has not ** been specified. ** ** In either case leave an error message in pParse and return non-zero. */ if( ( IsVirtual(pTab) && sqlite3GetVTable(pParse->db, pTab)->pMod->pModule->xUpdate==0 ) || ( (pTab->tabFlags & TF_Readonly)!=0 && (pParse->db->flags & SQLITE_WriteSchema)==0 && pParse->nested==0 ) ){ sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName); return 1; } #ifndef SQLITE_OMIT_VIEW if( !viewOk && pTab->pSelect ){ sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName); return 1; } #endif return 0; } #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) /* ** Evaluate a view and store its result in an ephemeral table. The ** pWhere argument is an optional WHERE clause that restricts the ** set of rows in the view that are to be added to the ephemeral table. */ void sqlite3MaterializeView( Parse *pParse, /* Parsing context */ Table *pView, /* View definition */ Expr *pWhere, /* Optional WHERE clause to be added */ int iCur /* Cursor number for ephemerial table */ ){ SelectDest dest; Select *pDup; sqlite3 *db = pParse->db; pDup = sqlite3SelectDup(db, pView->pSelect, 0); if( pWhere ){ SrcList *pFrom; pWhere = sqlite3ExprDup(db, pWhere, 0); pFrom = sqlite3SrcListAppend(db, 0, 0, 0); if( pFrom ){ assert( pFrom->nSrc==1 ); pFrom->a[0].zAlias = sqlite3DbStrDup(db, pView->zName); pFrom->a[0].pSelect = pDup; assert( pFrom->a[0].pOn==0 ); assert( pFrom->a[0].pUsing==0 ); }else{ sqlite3SelectDelete(db, pDup); } pDup = sqlite3SelectNew(pParse, 0, pFrom, pWhere, 0, 0, 0, 0, 0, 0); } sqlite3SelectDestInit(&dest, SRT_EphemTab, iCur); sqlite3Select(pParse, pDup, &dest); sqlite3SelectDelete(db, pDup); } #endif /* !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) */ #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) /* ** Generate an expression tree to implement the WHERE, ORDER BY, ** and LIMIT/OFFSET portion of DELETE and UPDATE statements. ** ** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1; ** \__________________________/ ** pLimitWhere (pInClause) */ Expr *sqlite3LimitWhere( Parse *pParse, /* The parser context */ SrcList *pSrc, /* the FROM clause -- which tables to scan */ Expr *pWhere, /* The WHERE clause. May be null */ ExprList *pOrderBy, /* The ORDER BY clause. May be null */ Expr *pLimit, /* The LIMIT clause. May be null */ Expr *pOffset, /* The OFFSET clause. May be null */ char *zStmtType /* Either DELETE or UPDATE. For error messages. */ ){ Expr *pWhereRowid = NULL; /* WHERE rowid .. */ Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */ Expr *pSelectRowid = NULL; /* SELECT rowid ... */ ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */ SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */ Select *pSelect = NULL; /* Complete SELECT tree */ /* Check that there isn't an ORDER BY without a LIMIT clause. */ if( pOrderBy && (pLimit == 0) ) { sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType); pParse->parseError = 1; goto limit_where_cleanup_2; } /* We only need to generate a select expression if there ** is a limit/offset term to enforce. */ if( pLimit == 0 ) { /* if pLimit is null, pOffset will always be null as well. */ assert( pOffset == 0 ); return pWhere; } /* Generate a select expression tree to enforce the limit/offset ** term for the DELETE or UPDATE statement. For example: ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1 ** becomes: ** DELETE FROM table_a WHERE rowid IN ( ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1 ** ); */ pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0); if( pSelectRowid == 0 ) goto limit_where_cleanup_2; pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid); if( pEList == 0 ) goto limit_where_cleanup_2; /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree ** and the SELECT subtree. */ pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0); if( pSelectSrc == 0 ) { sqlite3ExprListDelete(pParse->db, pEList); goto limit_where_cleanup_2; } /* generate the SELECT expression tree. */ pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0, pOrderBy,0,pLimit,pOffset); if( pSelect == 0 ) return 0; /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */ pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0); if( pWhereRowid == 0 ) goto limit_where_cleanup_1; pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0); if( pInClause == 0 ) goto limit_where_cleanup_1; pInClause->x.pSelect = pSelect; pInClause->flags |= EP_xIsSelect; sqlite3ExprSetHeight(pParse, pInClause); return pInClause; /* something went wrong. clean up anything allocated. */ limit_where_cleanup_1: sqlite3SelectDelete(pParse->db, pSelect); return 0; limit_where_cleanup_2: sqlite3ExprDelete(pParse->db, pWhere); sqlite3ExprListDelete(pParse->db, pOrderBy); sqlite3ExprDelete(pParse->db, pLimit); sqlite3ExprDelete(pParse->db, pOffset); return 0; } #endif /* defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) && !defined(SQLITE_OMIT_SUBQUERY) */ /* ** Generate code for a DELETE FROM statement. ** ** DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL; ** \________/ \________________/ ** pTabList pWhere */ void sqlite3DeleteFrom( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table from which we should delete things */ Expr *pWhere /* The WHERE clause. May be null */ ){ Vdbe *v; /* The virtual database engine */ Table *pTab; /* The table from which records will be deleted */ const char *zDb; /* Name of database holding pTab */ int end, addr = 0; /* A couple addresses of generated code */ int i; /* Loop counter */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Index *pIdx; /* For looping over indices of the table */ int iCur; /* VDBE Cursor number for pTab */ sqlite3 *db; /* Main database structure */ AuthContext sContext; /* Authorization context */ NameContext sNC; /* Name context to resolve expressions in */ int iDb; /* Database number */ int memCnt = -1; /* Memory cell used for change counting */ int rcauth; /* Value returned by authorization callback */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* True if attempting to delete from a view */ Trigger *pTrigger; /* List of table triggers, if required */ #endif memset(&sContext, 0, sizeof(sContext)); db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto delete_from_cleanup; } assert( pTabList->nSrc==1 ); /* Locate the table which we want to delete. This table has to be ** put in an SrcList structure because some of the subroutines we ** will be calling are designed to work with multiple tables and expect ** an SrcList* parameter instead of just a Table* parameter. */ pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto delete_from_cleanup; /* Figure out if we have any triggers and if the table being ** deleted from is a view */ #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_DELETE, 0, 0); isView = pTab->pSelect!=0; #else # define pTrigger 0 # define isView 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif /* If pTab is really a view, make sure it has been initialized. */ if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto delete_from_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, (pTrigger?1:0)) ){ goto delete_from_cleanup; } iDb = sqlite3SchemaToIndex(db, pTab->pSchema); assert( iDb<db->nDb ); zDb = db->aDb[iDb].zName; rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, zDb); assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE ); if( rcauth==SQLITE_DENY ){ goto delete_from_cleanup; } assert(!isView || pTrigger); /* Assign cursor number to the table and all its indices. */ assert( pTabList->nSrc==1 ); iCur = pTabList->a[0].iCursor = pParse->nTab++; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ pParse->nTab++; } /* Start the view context */ if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ){ goto delete_from_cleanup; } if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, 1, iDb); /* If we are trying to delete from a view, realize that view into ** a ephemeral table. */ #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, iCur); } #endif /* Resolve the column names in the WHERE clause. */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto delete_from_cleanup; } /* Initialize the counter of the number of rows deleted, if ** we are counting rows. */ if( db->flags & SQLITE_CountRows ){ memCnt = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, memCnt); } #ifndef SQLITE_OMIT_TRUNCATE_OPTIMIZATION /* Special case: A DELETE without a WHERE clause deletes everything. ** It is easier just to erase the whole table. Prior to version 3.6.5, ** this optimization caused the row change count (the value returned by ** API function sqlite3_count_changes) to be set incorrectly. */ if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) && 0==sqlite3FkRequired(pParse, pTab, 0, 0) ){ assert( !isView ); sqlite3VdbeAddOp4(v, OP_Clear, pTab->tnum, iDb, memCnt, pTab->zName, P4_STATIC); for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ assert( pIdx->pSchema==pTab->pSchema ); sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb); } }else #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */ /* The usual case: There is a WHERE clause so we have to scan through ** the table and pick which records to delete. */ { int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */ int iRowid = ++pParse->nMem; /* Used for storing rowid values. */ int regRowid; /* Actual register containing rowids */ /* Collect rowids of every row to be deleted. */ sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet); pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0,WHERE_DUPLICATES_OK); if( pWInfo==0 ) goto delete_from_cleanup; regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid); sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, regRowid); if( db->flags & SQLITE_CountRows ){ sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1); } sqlite3WhereEnd(pWInfo); /* Delete every item whose key was written to the list during the ** database scan. We have to delete items after the scan is complete ** because deleting an item can change the scan order. */ end = sqlite3VdbeMakeLabel(v); /* Unless this is a view, open cursors for the table we are ** deleting from and all its indices. If this is a view, then the ** only effect this statement has is to fire the INSTEAD OF ** triggers. */ if( !isView ){ sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite); } addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid); /* Delete the row */ #ifndef SQLITE_OMIT_VIRTUALTABLE if( IsVirtual(pTab) ){ const char *pVTab = (const char *)sqlite3GetVTable(db, pTab); sqlite3VtabMakeWritable(pParse, pTab); sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVTab, P4_VTAB); sqlite3MayAbort(pParse); }else #endif { int count = (pParse->nested==0); /* True to count changes */ sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, count, pTrigger, OE_Default); } /* End of the delete loop */ sqlite3VdbeAddOp2(v, OP_Goto, 0, addr); sqlite3VdbeResolveLabel(v, end); /* Close the cursors open on the table and its indexes. */ if( !isView && !IsVirtual(pTab) ){ for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum); } sqlite3VdbeAddOp1(v, OP_Close, iCur); } } /* Update the sqlite_sequence table by storing the content of the ** maximum rowid counter values recorded while inserting into ** autoincrement tables. */ if( pParse->nested==0 && pParse->pTriggerTab==0 ){ sqlite3AutoincrementEnd(pParse); } /* Return the number of rows that were deleted. If this routine is ** generating code because of a call to sqlite3NestedParse(), do not ** invoke the callback function. */ if( (db->flags&SQLITE_CountRows) && !pParse->nested && !pParse->pTriggerTab ){ sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", SQLITE_STATIC); } delete_from_cleanup: sqlite3AuthContextPop(&sContext); sqlite3SrcListDelete(db, pTabList); sqlite3ExprDelete(db, pWhere); return; } /* Make sure "isView" and other macros defined above are undefined. Otherwise ** thely may interfere with compilation of other functions in this file ** (or in another file, if this file becomes part of the amalgamation). */ #ifdef isView #undef isView #endif #ifdef pTrigger #undef pTrigger #endif /* ** This routine generates VDBE code that causes a single row of a ** single table to be deleted. ** ** The VDBE must be in a particular state when this routine is called. ** These are the requirements: ** ** 1. A read/write cursor pointing to pTab, the table containing the row ** to be deleted, must be opened as cursor number $iCur. ** ** 2. Read/write cursors for all indices of pTab must be open as ** cursor number base+i for the i-th index. ** ** 3. The record number of the row to be deleted must be stored in ** memory cell iRowid. ** ** This routine generates code to remove both the table record and all ** index entries that point to that record. */ void sqlite3GenerateRowDelete( Parse *pParse, /* Parsing context */ Table *pTab, /* Table containing the row to be deleted */ int iCur, /* Cursor number for the table */ int iRowid, /* Memory cell that contains the rowid to delete */ int count, /* If non-zero, increment the row change counter */ Trigger *pTrigger, /* List of triggers to (potentially) fire */ int onconf /* Default ON CONFLICT policy for triggers */ ){ Vdbe *v = pParse->pVdbe; /* Vdbe */ int iOld = 0; /* First register in OLD.* array */ int iLabel; /* Label resolved to end of generated code */ /* Vdbe is guaranteed to have been allocated by this stage. */ assert( v ); /* Seek cursor iCur to the row to delete. If this row no longer exists ** (this can happen if a trigger program has already deleted it), do ** not attempt to delete it or fire any DELETE triggers. */ iLabel = sqlite3VdbeMakeLabel(v); sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid); /* If there are any triggers to fire, allocate a range of registers to ** use for the old.* references in the triggers. */ if( sqlite3FkRequired(pParse, pTab, 0, 0) || pTrigger ){ u32 mask; /* Mask of OLD.* columns in use */ int iCol; /* Iterator used while populating OLD.* */ /* TODO: Could use temporary registers here. Also could attempt to ** avoid copying the contents of the rowid register. */ mask = sqlite3TriggerColmask( pParse, pTrigger, 0, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onconf ); mask |= sqlite3FkOldmask(pParse, pTab); iOld = pParse->nMem+1; pParse->nMem += (1 + pTab->nCol); /* Populate the OLD.* pseudo-table register array. These values will be ** used by any BEFORE and AFTER triggers that exist. */ sqlite3VdbeAddOp2(v, OP_Copy, iRowid, iOld); for(iCol=0; iCol<pTab->nCol; iCol++){ if( mask==0xffffffff || mask&(1<<iCol) ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, iCol, iOld+iCol+1); } } /* Invoke BEFORE DELETE trigger programs. */ sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel ); /* Seek the cursor to the row to be deleted again. It may be that ** the BEFORE triggers coded above have already removed the row ** being deleted. Do not attempt to delete the row a second time, and ** do not fire AFTER triggers. */ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, iLabel, iRowid); /* Do FK processing. This call checks that any FK constraints that ** refer to this table (i.e. constraints attached to other tables) ** are not violated by deleting this row. */ sqlite3FkCheck(pParse, pTab, iOld, 0); } /* Delete the index and table entries. Skip this step if pTab is really ** a view (in which case the only effect of the DELETE statement is to ** fire the INSTEAD OF triggers). */ if( pTab->pSelect==0 ){ sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, 0); sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0)); if( count ){ sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT); } } /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to ** handle rows (possibly in other tables) that refer via a foreign key ** to the row just deleted. */ sqlite3FkActions(pParse, pTab, 0, iOld); /* Invoke AFTER DELETE trigger programs. */ sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, TRIGGER_AFTER, pTab, iOld, onconf, iLabel ); /* Jump here if the row had already been deleted before any BEFORE ** trigger programs were invoked. Or if a trigger program throws a ** RAISE(IGNORE) exception. */ sqlite3VdbeResolveLabel(v, iLabel); } /* ** This routine generates VDBE code that causes the deletion of all ** index entries associated with a single row of a single table. ** ** The VDBE must be in a particular state when this routine is called. ** These are the requirements: ** ** 1. A read/write cursor pointing to pTab, the table containing the row ** to be deleted, must be opened as cursor number "iCur". ** ** 2. Read/write cursors for all indices of pTab must be open as ** cursor number iCur+i for the i-th index. ** ** 3. The "iCur" cursor must be pointing to the row that is to be ** deleted. */ void sqlite3GenerateRowIndexDelete( Parse *pParse, /* Parsing and code generating context */ Table *pTab, /* Table containing the row to be deleted */ int iCur, /* Cursor number for the table */ int *aRegIdx /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */ ){ int i; Index *pIdx; int r1; for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue; r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0); sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1); } } /* ** Generate code that will assemble an index key and put it in register ** regOut. The key with be for index pIdx which is an index on pTab. ** iCur is the index of a cursor open on the pTab table and pointing to ** the entry that needs indexing. ** ** Return a register number which is the first in a block of ** registers that holds the elements of the index key. The ** block of registers has already been deallocated by the time ** this routine returns. */ int sqlite3GenerateIndexKey( Parse *pParse, /* Parsing context */ Index *pIdx, /* The index for which to generate a key */ int iCur, /* Cursor number for the pIdx->pTable table */ int regOut, /* Write the new index key to this register */ int doMakeRec /* Run the OP_MakeRecord instruction if true */ ){ Vdbe *v = pParse->pVdbe; int j; Table *pTab = pIdx->pTable; int regBase; int nCol; nCol = pIdx->nColumn; regBase = sqlite3GetTempRange(pParse, nCol+1); sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol); for(j=0; j<nCol; j++){ int idx = pIdx->aiColumn[j]; if( idx==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j); }else{ sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j); sqlite3ColumnDefault(v, pTab, idx, -1); } } if( doMakeRec ){ sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut); sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT); } sqlite3ReleaseTempRange(pParse, regBase, nCol+1); return regBase; }