/* ** The most recently coded instruction was an OP_Column to retrieve the ** i-th column of table pTab. This routine sets the P4 parameter of the ** OP_Column to the default value, if any. ** ** The default value of a column is specified by a DEFAULT clause in the ** column definition. This was either supplied by the user when the table ** was created, or added later to the table definition by an ALTER TABLE ** command. If the latter, then the row-records in the table btree on disk ** may not contain a value for the column and the default value, taken ** from the P4 parameter of the OP_Column instruction, is returned instead. ** If the former, then all row-records are guaranteed to include a value ** for the column and the P4 value is not required. ** ** Column definitions created by an ALTER TABLE command may only have ** literal default values specified: a number, null or a string. (If a more ** complicated default expression value was provided, it is evaluated ** when the ALTER TABLE is executed and one of the literal values written ** into the sqlite_master table.) ** ** Therefore, the P4 parameter is only required if the default value for ** the column is a literal number, string or null. The sqlite3ValueFromExpr() ** function is capable of transforming these types of expressions into ** sqlite3_value objects. ** ** If parameter iReg is not negative, code an OP_RealAffinity instruction ** on register iReg. This is used when an equivalent integer value is ** stored in place of an 8-byte floating point value in order to save ** space. */ void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){ assert( pTab!=0 ); if( !pTab->pSelect ){ sqlite3_value *pValue = 0; u8 enc = ENC(sqlite3VdbeDb(v)); Column *pCol = &pTab->aCol[i]; VdbeComment((v, "%s.%s", pTab->zName, pCol->zName)); assert( i<pTab->nCol ); sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, pCol->affinity, &pValue); if( pValue ){ sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM); } #ifndef SQLITE_OMIT_FLOATING_POINT if( pTab->aCol[i].affinity==SQLITE_AFF_REAL ){ sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg); } #endif } }
/* ** Generate code for an UPDATE of a virtual table. ** ** There are two possible strategies - the default and the special ** "onepass" strategy. Onepass is only used if the virtual table ** implementation indicates that pWhere may match at most one row. ** ** The default strategy is to create an ephemeral table that contains ** for each row to be changed: ** ** (A) The original rowid of that row. ** (B) The revised rowid for the row. ** (C) The content of every column in the row. ** ** Then loop through the contents of this ephemeral table executing a ** VUpdate for each row. When finished, drop the ephemeral table. ** ** The "onepass" strategy does not use an ephemeral table. Instead, it ** stores the same values (A, B and C above) in a register array and ** makes a single invocation of VUpdate. */ static void updateVirtualTable( Parse *pParse, /* The parsing context */ SrcList *pSrc, /* The virtual table to be modified */ Table *pTab, /* The virtual table */ ExprList *pChanges, /* The columns to change in the UPDATE statement */ Expr *pRowid, /* Expression used to recompute the rowid */ int *aXRef, /* Mapping from columns of pTab to entries in pChanges */ Expr *pWhere, /* WHERE clause of the UPDATE statement */ int onError /* ON CONFLICT strategy */ ){ Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */ int ephemTab; /* Table holding the result of the SELECT */ int i; /* Loop counter */ sqlite3 *db = pParse->db; /* Database connection */ const char *pVTab = (const char*)sqlite3GetVTable(db, pTab); WhereInfo *pWInfo; int nArg = 2 + pTab->nCol; /* Number of arguments to VUpdate */ int regArg; /* First register in VUpdate arg array */ int regRec; /* Register in which to assemble record */ int regRowid; /* Register for ephem table rowid */ int iCsr = pSrc->a[0].iCursor; /* Cursor used for virtual table scan */ int aDummy[2]; /* Unused arg for sqlite3WhereOkOnePass() */ int bOnePass; /* True to use onepass strategy */ int addr; /* Address of OP_OpenEphemeral */ /* Allocate nArg registers to martial the arguments to VUpdate. Then ** create and open the ephemeral table in which the records created from ** these arguments will be temporarily stored. */ assert( v ); ephemTab = pParse->nTab++; addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg); regArg = pParse->nMem + 1; pParse->nMem += nArg; regRec = ++pParse->nMem; regRowid = ++pParse->nMem; /* Start scanning the virtual table */ pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0); if( pWInfo==0 ) return; /* Populate the argument registers. */ sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg); if( pRowid ){ sqlite3ExprCode(pParse, pRowid, regArg+1); }else{ sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1); } for(i=0; i<pTab->nCol; i++){ if( aXRef[i]>=0 ){ sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i); }else{ sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i); } } bOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy); if( bOnePass ){ /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded ** above. Also, if this is a top-level parse (not a trigger), clear the ** multi-write flag so that the VM does not open a statement journal */ sqlite3VdbeChangeToNoop(v, addr); if( sqlite3IsToplevel(pParse) ){ pParse->isMultiWrite = 0; } }else{ /* Create a record from the argument register contents and insert it into ** the ephemeral table. */ sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec); sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid); } if( bOnePass==0 ){ /* End the virtual table scan */ sqlite3WhereEnd(pWInfo); /* Begin scannning through the ephemeral table. */ addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v); /* Extract arguments from the current row of the ephemeral table and ** invoke the VUpdate method. */ for(i=0; i<nArg; i++){ sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i); } } sqlite3VtabMakeWritable(pParse, pTab); sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB); sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError); sqlite3MayAbort(pParse); /* End of the ephemeral table scan. Or, if using the onepass strategy, ** jump to here if the scan visited zero rows. */ if( bOnePass==0 ){ sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v); sqlite3VdbeJumpHere(v, addr); sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0); }else{ sqlite3WhereEnd(pWInfo); } }
/* ** This procedure generates VDBE code for a single invocation of either the ** sqlite_detach() or sqlite_attach() SQL user functions. */ static void codeAttach( Parse *pParse, /* The parser context */ int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */ const char *zFunc, /* Either "sqlite_attach" or "sqlite_detach */ int nFunc, /* Number of args to pass to zFunc */ Expr *pAuthArg, /* Expression to pass to authorization callback */ Expr *pFilename, /* Name of database file */ Expr *pDbname, /* Name of the database to use internally */ Expr *pKey /* Database key for encryption extension */ ){ int rc; NameContext sName; Vdbe *v; FuncDef *pFunc; sqlite3* db = pParse->db; int regArgs; #ifndef SQLITE_OMIT_AUTHORIZATION assert( db->mallocFailed || pAuthArg ); if( pAuthArg ){ char *zAuthArg = sqlite3NameFromToken(db, &pAuthArg->span); if( !zAuthArg ){ goto attach_end; } rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0); sqlite3_free(zAuthArg); if(rc!=SQLITE_OK ){ goto attach_end; } } #endif /* SQLITE_OMIT_AUTHORIZATION */ memset(&sName, 0, sizeof(NameContext)); sName.pParse = pParse; if( SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) || SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) || SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey)) ){ pParse->nErr++; goto attach_end; } v = sqlite3GetVdbe(pParse); regArgs = sqlite3GetTempRange(pParse, 3); sqlite3ExprCode(pParse, pFilename, regArgs); sqlite3ExprCode(pParse, pDbname, regArgs+1); sqlite3ExprCode(pParse, pKey, regArgs+2); assert( v || db->mallocFailed ); if( v ){ sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-nFunc, regArgs); sqlite3VdbeChangeP5(v, nFunc); pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0); sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF); /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this ** statement only). For DETACH, set it to false (expire all existing ** statements). */ sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH)); } attach_end: sqlite3ExprDelete(pFilename); sqlite3ExprDelete(pDbname); sqlite3ExprDelete(pKey); }
/* ** 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, 0, WHERE_DUPLICATES_OK, 0 ); if( pWInfo==0 ) goto delete_from_cleanup; regRowid = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, iRowid, 0); 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); sqlite3VdbeChangeP5(v, OE_Abort); 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; }
/* ** Process an UPDATE statement. ** ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; ** \_______/ \________/ \______/ \________________/ * onError pTabList pChanges pWhere */ void sqlite3Update( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table in which we should change things */ ExprList *pChanges, /* Things to be changed */ Expr *pWhere, /* The WHERE clause. May be null */ int onError, /* How to handle constraint errors */ ExprList *pOrderBy, /* ORDER BY clause. May be null */ Expr *pLimit, /* LIMIT clause. May be null */ Upsert *pUpsert /* ON CONFLICT clause, or null */ ){ int i, j; /* Loop counters */ Table *pTab; /* The table to be updated */ int addrTop = 0; /* VDBE instruction address of the start of the loop */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Vdbe *v; /* The virtual database engine */ Index *pIdx; /* For looping over indices */ Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */ int nIdx; /* Number of indices that need updating */ int iBaseCur; /* Base cursor number */ int iDataCur; /* Cursor for the canonical data btree */ int iIdxCur; /* Cursor for the first index */ sqlite3 *db; /* The database structure */ int *aRegIdx = 0; /* First register in array assigned to each index */ int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the ** an expression for the i-th column of the table. ** aXRef[i]==-1 if the i-th column is not changed. */ u8 *aToOpen; /* 1 for tables and indices to be opened */ u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */ u8 chngRowid; /* Rowid changed in a normal table */ u8 chngKey; /* Either chngPk or chngRowid */ Expr *pRowidExpr = 0; /* Expression defining the new record number */ AuthContext sContext; /* The authorization context */ NameContext sNC; /* The name-context to resolve expressions in */ int iDb; /* Database containing the table being updated */ int eOnePass; /* ONEPASS_XXX value from where.c */ int hasFK; /* True if foreign key processing is required */ int labelBreak; /* Jump here to break out of UPDATE loop */ int labelContinue; /* Jump here to continue next step of UPDATE loop */ int flags; /* Flags for sqlite3WhereBegin() */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* True when updating a view (INSTEAD OF trigger) */ Trigger *pTrigger; /* List of triggers on pTab, if required */ int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ #endif int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */ int iEph = 0; /* Ephemeral table holding all primary key values */ int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */ int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */ int addrOpen = 0; /* Address of OP_OpenEphemeral */ int iPk = 0; /* First of nPk cells holding PRIMARY KEY value */ i16 nPk = 0; /* Number of components of the PRIMARY KEY */ int bReplace = 0; /* True if REPLACE conflict resolution might happen */ /* Register Allocations */ int regRowCount = 0; /* A count of rows changed */ int regOldRowid = 0; /* The old rowid */ int regNewRowid = 0; /* The new rowid */ int regNew = 0; /* Content of the NEW.* table in triggers */ int regOld = 0; /* Content of OLD.* table in triggers */ int regRowSet = 0; /* Rowset of rows to be updated */ int regKey = 0; /* composite PRIMARY KEY value */ memset(&sContext, 0, sizeof(sContext)); db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto update_cleanup; } assert( pTabList->nSrc==1 ); /* Locate the table which we want to update. */ pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto update_cleanup; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); /* Figure out if we have any triggers and if the table being ** updated is a view. */ #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask); isView = pTab->pSelect!=0; assert( pTrigger || tmask==0 ); #else # define pTrigger 0 # define isView 0 # define tmask 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif #ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT if( !isView ){ pWhere = sqlite3LimitWhere( pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE" ); pOrderBy = 0; pLimit = 0; } #endif if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, tmask) ){ goto update_cleanup; } /* Allocate a cursors for the main database table and for all indices. ** The index cursors might not be used, but if they are used they ** need to occur right after the database cursor. So go ahead and ** allocate enough space, just in case. */ iBaseCur = iDataCur = pParse->nTab++; iIdxCur = iDataCur+1; pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab); testcase( pPk!=0 && pPk!=pTab->pIndex ); for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ if( pPk==pIdx ){ iDataCur = pParse->nTab; } pParse->nTab++; } if( pUpsert ){ /* On an UPSERT, reuse the same cursors already opened by INSERT */ iDataCur = pUpsert->iDataCur; iIdxCur = pUpsert->iIdxCur; pParse->nTab = iBaseCur; } pTabList->a[0].iCursor = iDataCur; /* Allocate space for aXRef[], aRegIdx[], and aToOpen[]. ** Initialize aXRef[] and aToOpen[] to their default values. */ aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 ); if( aXRef==0 ) goto update_cleanup; aRegIdx = aXRef+pTab->nCol; aToOpen = (u8*)(aRegIdx+nIdx); memset(aToOpen, 1, nIdx+1); aToOpen[nIdx+1] = 0; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; /* Initialize the name-context */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; sNC.uNC.pUpsert = pUpsert; sNC.ncFlags = NC_UUpsert; /* Resolve the column names in all the expressions of the ** of the UPDATE statement. Also find the column index ** for each column to be updated in the pChanges array. For each ** column to be updated, make sure we have authorization to change ** that column. */ chngRowid = chngPk = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){ chngPk = 1; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){ j = -1; chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); pParse->checkSchema = 1; goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, j<0 ? "ROWID" : pTab->aCol[j].zName, db->aDb[iDb].zDbSName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } assert( (chngRowid & chngPk)==0 ); assert( chngRowid==0 || chngRowid==1 ); assert( chngPk==0 || chngPk==1 ); chngKey = chngRowid + chngPk; /* The SET expressions are not actually used inside the WHERE loop. ** So reset the colUsed mask. Unless this is a virtual table. In that ** case, set all bits of the colUsed mask (to ensure that the virtual ** table implementation makes all columns available). */ pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0; hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey); /* There is one entry in the aRegIdx[] array for each index on the table ** being updated. Fill in aRegIdx[] with a register number that will hold ** the key for accessing each index. */ if( onError==OE_Replace ) bReplace = 1; for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngKey || hasFK>1 || pIdx==pPk || indexWhereClauseMightChange(pIdx,aXRef,chngRowid) ){ reg = ++pParse->nMem; pParse->nMem += pIdx->nColumn; }else{ reg = 0; for(i=0; i<pIdx->nKeyCol; i++){ if( indexColumnIsBeingUpdated(pIdx, i, aXRef, chngRowid) ){ reg = ++pParse->nMem; pParse->nMem += pIdx->nColumn; if( onError==OE_Default && pIdx->onError==OE_Replace ){ bReplace = 1; } break; } } } if( reg==0 ) aToOpen[j+1] = 0; aRegIdx[j] = reg; } if( bReplace ){ /* If REPLACE conflict resolution might be invoked, open cursors on all ** indexes in case they are needed to delete records. */ memset(aToOpen, 1, nIdx+1); } /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, pTrigger || hasFK, iDb); /* Allocate required registers. */ if( !IsVirtual(pTab) ){ regRowSet = ++pParse->nMem; regOldRowid = regNewRowid = ++pParse->nMem; if( chngPk || pTrigger || hasFK ){ regOld = pParse->nMem + 1; pParse->nMem += pTab->nCol; } if( chngKey || pTrigger || hasFK ){ regNewRowid = ++pParse->nMem; } regNew = pParse->nMem + 1; pParse->nMem += pTab->nCol; } /* Start the view context. */ if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } /* If we are trying to update a view, realize that view into ** an ephemeral table. */ #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, pOrderBy, pLimit, iDataCur ); pOrderBy = 0; pLimit = 0; } #endif /* Resolve the column names in all the expressions in the ** WHERE clause. */ if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } #ifndef SQLITE_OMIT_VIRTUALTABLE /* Virtual tables must be handled separately */ if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere, onError); goto update_cleanup; } #endif /* Jump to labelBreak to abandon further processing of this UPDATE */ labelContinue = labelBreak = sqlite3VdbeMakeLabel(pParse); /* Not an UPSERT. Normal processing. Begin by ** initialize the count of updated rows */ if( (db->flags&SQLITE_CountRows)!=0 && !pParse->pTriggerTab && !pParse->nested && pUpsert==0 ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } if( HasRowid(pTab) ){ sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid); }else{ assert( pPk!=0 ); nPk = pPk->nKeyCol; iPk = pParse->nMem+1; pParse->nMem += nPk; regKey = ++pParse->nMem; if( pUpsert==0 ){ iEph = pParse->nTab++; sqlite3VdbeAddOp3(v, OP_Null, 0, iPk, iPk+nPk-1); addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk); sqlite3VdbeSetP4KeyInfo(pParse, pPk); } } if( pUpsert ){ /* If this is an UPSERT, then all cursors have already been opened by ** the outer INSERT and the data cursor should be pointing at the row ** that is to be updated. So bypass the code that searches for the ** row(s) to be updated. */ pWInfo = 0; eOnePass = ONEPASS_SINGLE; sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL); }else{ /* Begin the database scan. ** ** Do not consider a single-pass strategy for a multi-row update if ** there are any triggers or foreign keys to process, or rows may ** be deleted as a result of REPLACE conflict handling. Any of these ** things might disturb a cursor being used to scan through the table ** or index, causing a single-pass approach to malfunction. */ flags = WHERE_ONEPASS_DESIRED|WHERE_SEEK_UNIQ_TABLE; if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){ flags |= WHERE_ONEPASS_MULTIROW; } pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, flags, iIdxCur); if( pWInfo==0 ) goto update_cleanup; /* A one-pass strategy that might update more than one row may not ** be used if any column of the index used for the scan is being ** updated. Otherwise, if there is an index on "b", statements like ** the following could create an infinite loop: ** ** UPDATE t1 SET b=b+1 WHERE b>? ** ** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI ** strategy that uses an index for which one or more columns are being ** updated. */ eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); if( eOnePass!=ONEPASS_SINGLE ){ sqlite3MultiWrite(pParse); if( eOnePass==ONEPASS_MULTI ){ int iCur = aiCurOnePass[1]; if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){ eOnePass = ONEPASS_OFF; } assert( iCur!=iDataCur || !HasRowid(pTab) ); } } } if( HasRowid(pTab) ){ /* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF ** mode, write the rowid into the FIFO. In either of the one-pass modes, ** leave it in register regOldRowid. */ sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid); if( eOnePass==ONEPASS_OFF ){ sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } }else{ /* Read the PK of the current row into an array of registers. In ** ONEPASS_OFF mode, serialize the array into a record and store it in ** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change ** the OP_OpenEphemeral instruction to a Noop (the ephemeral table ** is not required) and leave the PK fields in the array of registers. */ for(i=0; i<nPk; i++){ assert( pPk->aiColumn[i]>=0 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,pPk->aiColumn[i],iPk+i); } if( eOnePass ){ if( addrOpen ) sqlite3VdbeChangeToNoop(v, addrOpen); nKey = nPk; regKey = iPk; }else{ sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey, sqlite3IndexAffinityStr(db, pPk), nPk); sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk); } } if( pUpsert==0 ){ if( eOnePass!=ONEPASS_MULTI ){ sqlite3WhereEnd(pWInfo); } if( !isView ){ int addrOnce = 0; /* Open every index that needs updating. */ if( eOnePass!=ONEPASS_OFF ){ if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0; if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0; } if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){ addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur, aToOpen, 0, 0); if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce); } /* Top of the update loop */ if( eOnePass!=ONEPASS_OFF ){ if( !isView && aiCurOnePass[0]!=iDataCur && aiCurOnePass[1]!=iDataCur ){ assert( pPk ); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey,nKey); VdbeCoverage(v); } if( eOnePass!=ONEPASS_SINGLE ){ labelContinue = sqlite3VdbeMakeLabel(pParse); } sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak); VdbeCoverageIf(v, pPk==0); VdbeCoverageIf(v, pPk!=0); }else if( pPk ){ labelContinue = sqlite3VdbeMakeLabel(pParse); sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v); addrTop = sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0); VdbeCoverage(v); }else{ labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet,labelBreak, regOldRowid); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } } /* If the rowid value will change, set register regNewRowid to ** contain the new value. If the rowid is not being modified, ** then regNewRowid is the same register as regOldRowid, which is ** already populated. */ assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid ); if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v); } /* Compute the old pre-UPDATE content of the row being changed, if that ** information is needed */ if( chngPk || hasFK || pTrigger ){ u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0); oldmask |= sqlite3TriggerColmask(pParse, pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( oldmask==0xffffffff || (i<32 && (oldmask & MASKBIT32(i))!=0) || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){ testcase( oldmask!=0xffffffff && i==31 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i); } } if( chngRowid==0 && pPk==0 ){ sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid); } } /* Populate the array of registers beginning at regNew with the new ** row data. This array is used to check constants, create the new ** table and index records, and as the values for any new.* references ** made by triggers. ** ** If there are one or more BEFORE triggers, then do not populate the ** registers associated with columns that are (a) not modified by ** this UPDATE statement and (b) not accessed by new.* references. The ** values for registers not modified by the UPDATE must be reloaded from ** the database after the BEFORE triggers are fired anyway (as the trigger ** may have modified them). So not loading those that are not going to ** be used eliminates some redundant opcodes. */ newmask = sqlite3TriggerColmask( pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); }else{ j = aXRef[i]; if( j>=0 ){ sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i); }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){ /* This branch loads the value of a column that will not be changed ** into a register. This is done if there are no BEFORE triggers, or ** if there are one or more BEFORE triggers that use this value via ** a new.* reference in a trigger program. */ testcase( i==31 ); testcase( i==32 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); } } } /* Fire any BEFORE UPDATE triggers. This happens before constraints are ** verified. One could argue that this is wrong. */ if( tmask&TRIGGER_BEFORE ){ sqlite3TableAffinity(v, pTab, regNew); sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue); /* The row-trigger may have deleted the row being updated. In this ** case, jump to the next row. No updates or AFTER triggers are ** required. This behavior - what happens when the row being updated ** is deleted or renamed by a BEFORE trigger - is left undefined in the ** documentation. */ if( pPk ){ sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey); VdbeCoverage(v); }else{ sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } /* After-BEFORE-trigger-reload-loop: ** If it did not delete it, the BEFORE trigger may still have modified ** some of the columns of the row being updated. Load the values for ** all columns not modified by the update statement into their registers ** in case this has happened. Only unmodified columns are reloaded. ** The values computed for modified columns use the values before the ** BEFORE trigger runs. See test case trigger1-18.0 (added 2018-04-26) ** for an example. */ for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 && i!=pTab->iPKey ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i); } } } if( !isView ){ int addr1 = 0; /* Address of jump instruction */ /* Do constraint checks. */ assert( regOldRowid>0 ); sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur, regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace, aXRef, 0); /* Do FK constraint checks. */ if( hasFK ){ sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey); } /* Delete the index entries associated with the current record. */ if( bReplace || chngKey ){ if( pPk ){ addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey); }else{ addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid); } VdbeCoverageNeverTaken(v); } sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1); /* If changing the rowid value, or if there are foreign key constraints ** to process, delete the old record. Otherwise, add a noop OP_Delete ** to invoke the pre-update hook. ** ** That (regNew==regnewRowid+1) is true is also important for the ** pre-update hook. If the caller invokes preupdate_new(), the returned ** value is copied from memory cell (regNewRowid+1+iCol), where iCol ** is the column index supplied by the user. */ assert( regNew==regNewRowid+1 ); #ifdef SQLITE_ENABLE_PREUPDATE_HOOK sqlite3VdbeAddOp3(v, OP_Delete, iDataCur, OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP), regNewRowid ); if( eOnePass==ONEPASS_MULTI ){ assert( hasFK==0 && chngKey==0 ); sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION); } if( !pParse->nested ){ sqlite3VdbeAppendP4(v, pTab, P4_TABLE); } #else if( hasFK>1 || chngKey ){ sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0); } #endif if( bReplace || chngKey ){ sqlite3VdbeJumpHere(v, addr1); } if( hasFK ){ sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey); } /* Insert the new index entries and the new record. */ sqlite3CompleteInsertion( pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx, OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0), 0, 0 ); /* 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 updated. */ if( hasFK ){ sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey); } } /* Increment the row counter */ if( regRowCount ){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue); /* Repeat the above with the next record to be updated, until ** all record selected by the WHERE clause have been updated. */ if( eOnePass==ONEPASS_SINGLE ){ /* Nothing to do at end-of-loop for a single-pass */ }else if( eOnePass==ONEPASS_MULTI ){ sqlite3VdbeResolveLabel(v, labelContinue); sqlite3WhereEnd(pWInfo); }else if( pPk ){ sqlite3VdbeResolveLabel(v, labelContinue); sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v); }else{ sqlite3VdbeGoto(v, labelContinue); } sqlite3VdbeResolveLabel(v, labelBreak); /* 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 && pUpsert==0 ){ sqlite3AutoincrementEnd(pParse); } /* ** Return the number of rows that were changed, if we are tracking ** that information. */ if( regRowCount ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */ sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) sqlite3ExprListDelete(db, pOrderBy); sqlite3ExprDelete(db, pLimit); #endif return; }
void sqlite3Update( Parse *pParse, SrcList *pTabList, ExprList *pChanges, Expr *pWhere, int onError ){ int i, j; Table *pTab; int addr = 0; WhereInfo *pWInfo; Vdbe *v; Index *pIdx; int nIdx; int iCur; sqlite3 *db; int *aRegIdx = 0; int *aXRef = 0; int chngRowid; Expr *pRowidExpr = 0; int openAll = 0; AuthContext sContext; NameContext sNC; int iDb; int okOnePass; int hasFK; #ifndef SQLITE_OMIT_TRIGGER int isView; Trigger *pTrigger; int tmask; #endif int newmask; int regRowCount = 0; int regOldRowid; int regNewRowid; int regNew; int regOld = 0; int regRowSet = 0; memset(&sContext, 0, sizeof(sContext)); db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto update_cleanup; } assert( pTabList->nSrc==1 ); pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto update_cleanup; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask); isView = pTab->pSelect!=0; assert( pTrigger || tmask==0 ); #else # define pTrigger 0 # define isView 0 # define tmask 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, tmask) ){ goto update_cleanup; } aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol ); if( aXRef==0 ) goto update_cleanup; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; pTabList->a[0].iCursor = iCur = pParse->nTab++; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ pParse->nTab++; } memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; chngRowid = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( sqlite3IsRowid(pChanges->a[i].zName) ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); pParse->checkSchema = 1; goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, pTab->aCol[j].zName, db->aDb[iDb].zName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngRowid); for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){} if( nIdx>0 ){ aRegIdx = sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx ); if( aRegIdx==0 ) goto update_cleanup; } for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngRowid ){ reg = ++pParse->nMem; }else{ reg = 0; for(i=0; i<pIdx->nColumn; i++){ if( aXRef[pIdx->aiColumn[i]]>=0 ){ reg = ++pParse->nMem; break; } } } aRegIdx[j] = reg; } v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, 1, iDb); #ifndef SQLITE_OMIT_VIRTUALTABLE if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere); pWhere = 0; pTabList = 0; goto update_cleanup; } #endif regOldRowid = regNewRowid = ++pParse->nMem; if( pTrigger || hasFK ){ regOld = pParse->nMem + 1; pParse->nMem += pTab->nCol; } if( chngRowid || pTrigger || hasFK ){ regNewRowid = ++pParse->nMem; } regNew = pParse->nMem + 1; pParse->nMem += pTab->nCol; if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, iCur); } #endif if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } sqlite3VdbeAddOp2(v, OP_Null, 0, regOldRowid); pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0, WHERE_ONEPASS_DESIRED); if( pWInfo==0 ) goto update_cleanup; okOnePass = pWInfo->okOnePass; sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regOldRowid); if( !okOnePass ){ regRowSet = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } sqlite3WhereEnd(pWInfo); if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } if( !isView ){ if( !okOnePass ) sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); if( onError==OE_Replace ){ openAll = 1; }else{ openAll = 0; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->onError==OE_Replace ){ openAll = 1; break; } } } for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ if( openAll || aRegIdx[i]>0 ){ KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); sqlite3VdbeAddOp4(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, iDb, (char*)pKey, P4_KEYINFO_HANDOFF); assert( pParse->nTab>iCur+i+1 ); } } } if( okOnePass ){ int a1 = sqlite3VdbeAddOp1(v, OP_NotNull, regOldRowid); addr = sqlite3VdbeAddOp0(v, OP_Goto); sqlite3VdbeJumpHere(v, a1); }else{ addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, 0, regOldRowid); } sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid); assert( chngRowid || pTrigger || hasFK || regOldRowid==regNewRowid ); if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); } if( hasFK || pTrigger ){ u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0); oldmask |= sqlite3TriggerColmask(pParse, pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 || oldmask==0xffffffff || (i<32 && (oldmask & (1<<i))) ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, i, regOld+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i); } } if( chngRowid==0 ){ sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid); } } newmask = sqlite3TriggerColmask( pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); }else{ j = aXRef[i]; if( j>=0 ){ sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i); }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask&(1<<i)) ){ testcase( i==31 ); testcase( i==32 ); sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regNew+i); sqlite3ColumnDefault(v, pTab, i, regNew+i); } } } if( tmask&TRIGGER_BEFORE ){ sqlite3VdbeAddOp2(v, OP_Affinity, regNew, pTab->nCol); sqlite3TableAffinityStr(v, pTab); sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, regOldRowid, onError, addr); sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid); for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 && i!=pTab->iPKey ){ sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regNew+i); sqlite3ColumnDefault(v, pTab, i, regNew+i); } } } if( !isView ){ int j1; sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid, aRegIdx, (chngRowid?regOldRowid:0), 1, onError, addr, 0); if( hasFK ){ sqlite3FkCheck(pParse, pTab, regOldRowid, 0); } j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regOldRowid); sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, aRegIdx); if( hasFK || chngRowid ){ sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0); } sqlite3VdbeJumpHere(v, j1); if( hasFK ){ sqlite3FkCheck(pParse, pTab, 0, regNewRowid); } sqlite3CompleteInsertion(pParse, pTab, iCur, regNewRowid, aRegIdx, 1, 0, 0); if( hasFK ){ sqlite3FkActions(pParse, pTab, pChanges, regOldRowid); } } if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, regOldRowid, onError, addr); sqlite3VdbeAddOp2(v, OP_Goto, 0, addr); sqlite3VdbeJumpHere(v, addr); for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ if( openAll || aRegIdx[i]>0 ){ sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0); } } sqlite3VdbeAddOp2(v, OP_Close, iCur, 0); if( pParse->nested==0 && pParse->pTriggerTab==0 ){ sqlite3AutoincrementEnd(pParse); } if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aRegIdx); sqlite3DbFree(db, aXRef); sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); return; }
static void codeAttach( Parse *pParse, int type, FuncDef const *pFunc, Expr *pAuthArg, Expr *pFilename, Expr *pDbname, Expr *pKey ){ int rc; NameContext sName; Vdbe *v; sqlite3* db = pParse->db; int regArgs; memset(&sName, 0, sizeof(NameContext)); sName.pParse = pParse; if( SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) || SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) || SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey)) ){ pParse->nErr++; goto attach_end; } #ifndef SQLITE_OMIT_AUTHORIZATION if( pAuthArg ){ char *zAuthArg; if( pAuthArg->op==TK_STRING ){ zAuthArg = pAuthArg->u.zToken; }else{ zAuthArg = 0; } rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0); if(rc!=SQLITE_OK ){ goto attach_end; } } #endif v = sqlite3GetVdbe(pParse); regArgs = sqlite3GetTempRange(pParse, 4); sqlite3ExprCode(pParse, pFilename, regArgs); sqlite3ExprCode(pParse, pDbname, regArgs+1); sqlite3ExprCode(pParse, pKey, regArgs+2); assert( v || db->mallocFailed ); if( v ){ sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3); assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg ); sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg)); sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF); sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH)); } attach_end: sqlite3ExprDelete(db, pFilename); sqlite3ExprDelete(db, pDbname); sqlite3ExprDelete(db, pKey); }
/* ** 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 */ int i; /* Loop counter */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Index *pIdx; /* For looping over indices of the table */ int iTabCur; /* Cursor number for the table */ int iDataCur = 0; /* VDBE cursor for the canonical data source */ int iIdxCur = 0; /* Cursor number of the first index */ int nIdx; /* Number of indices */ 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 */ int eOnePass; /* ONEPASS_OFF or _SINGLE or _MULTI */ int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */ u8 *aToOpen = 0; /* Open cursor iTabCur+j if aToOpen[j] is true */ Index *pPk; /* The PRIMARY KEY index on the table */ int iPk = 0; /* First of nPk registers holding PRIMARY KEY value */ i16 nPk = 1; /* Number of columns in the PRIMARY KEY */ int iKey; /* Memory cell holding key of row to be deleted */ i16 nKey; /* Number of memory cells in the row key */ int iEphCur = 0; /* Ephemeral table holding all primary key values */ int iRowSet = 0; /* Register for rowset of rows to delete */ int addrBypass = 0; /* Address of jump over the delete logic */ int addrLoop = 0; /* Top of the delete loop */ int addrEphOpen = 0; /* Instruction to open the Ephemeral table */ int bComplex; /* True if there are triggers or FKs or ** subqueries in the WHERE clause */ #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; bComplex = pTrigger || sqlite3FkRequired(pParse, pTab, 0, 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 ); rcauth = sqlite3AuthCheck(pParse, SQLITE_DELETE, pTab->zName, 0, db->aDb[iDb].zDbSName); assert( rcauth==SQLITE_OK || rcauth==SQLITE_DENY || rcauth==SQLITE_IGNORE ); if( rcauth==SQLITE_DENY ){ goto delete_from_cleanup; } assert(!isView || pTrigger); /* Assign cursor numbers to the table and all its indices. */ assert( pTabList->nSrc==1 ); iTabCur = pTabList->a[0].iCursor = pParse->nTab++; for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ 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 ** an ephemeral table. */ #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, iTabCur); iDataCur = iIdxCur = iTabCur; } #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 && !bComplex && !IsVirtual(pTab) #ifdef SQLITE_ENABLE_PREUPDATE_HOOK && db->xPreUpdateCallback==0 #endif ){ assert( !isView ); sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName); if( HasRowid(pTab) ){ 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 */ { u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK|WHERE_SEEK_TABLE; if( sNC.ncFlags & NC_VarSelect ) bComplex = 1; wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW); if( HasRowid(pTab) ){ /* For a rowid table, initialize the RowSet to an empty set */ pPk = 0; nPk = 1; iRowSet = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Null, 0, iRowSet); }else{ /* For a WITHOUT ROWID table, create an ephemeral table used to ** hold all primary keys for rows to be deleted. */ pPk = sqlite3PrimaryKeyIndex(pTab); assert( pPk!=0 ); nPk = pPk->nKeyCol; iPk = pParse->nMem+1; pParse->nMem += nPk; iEphCur = pParse->nTab++; addrEphOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEphCur, nPk); sqlite3VdbeSetP4KeyInfo(pParse, pPk); } /* Construct a query to find the rowid or primary key for every row ** to be deleted, based on the WHERE clause. Set variable eOnePass ** to indicate the strategy used to implement this delete: ** ** ONEPASS_OFF: Two-pass approach - use a FIFO for rowids/PK values. ** ONEPASS_SINGLE: One-pass approach - at most one row deleted. ** ONEPASS_MULTI: One-pass approach - any number of rows may be deleted. */ pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, wcf, iTabCur+1); if( pWInfo==0 ) goto delete_from_cleanup; eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI ); assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF ); /* Keep track of the number of rows to be deleted */ if( db->flags & SQLITE_CountRows ){ sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1); } /* Extract the rowid or primary key for the current row */ if( pPk ){ for(i=0; i<nPk; i++){ assert( pPk->aiColumn[i]>=0 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, pPk->aiColumn[i], iPk+i); } iKey = iPk; }else{ iKey = pParse->nMem + 1; iKey = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iTabCur, iKey, 0); if( iKey>pParse->nMem ) pParse->nMem = iKey; } if( eOnePass!=ONEPASS_OFF ){ /* For ONEPASS, no need to store the rowid/primary-key. There is only ** one, so just keep it in its register(s) and fall through to the ** delete code. */ nKey = nPk; /* OP_Found will use an unpacked key */ aToOpen = sqlite3DbMallocRawNN(db, nIdx+2); if( aToOpen==0 ){ sqlite3WhereEnd(pWInfo); goto delete_from_cleanup; } memset(aToOpen, 1, nIdx+1); aToOpen[nIdx+1] = 0; if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0; if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0; if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen); }else{ if( pPk ){ /* Add the PK key for this row to the temporary table */ iKey = ++pParse->nMem; nKey = 0; /* Zero tells OP_Found to use a composite key */ sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, iKey, sqlite3IndexAffinityStr(pParse->db, pPk), nPk); sqlite3VdbeAddOp2(v, OP_IdxInsert, iEphCur, iKey); }else{ /* Add the rowid of the row to be deleted to the RowSet */ nKey = 1; /* OP_Seek always uses a single rowid */ sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey); } } /* If this DELETE cannot use the ONEPASS strategy, this is the ** end of the WHERE loop */ if( eOnePass!=ONEPASS_OFF ){ addrBypass = sqlite3VdbeMakeLabel(v); }else{ sqlite3WhereEnd(pWInfo); } /* 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 ){ int iAddrOnce = 0; if( eOnePass==ONEPASS_MULTI ){ iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } testcase( IsVirtual(pTab) ); sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, OPFLAG_FORDELETE, iTabCur, aToOpen, &iDataCur, &iIdxCur); assert( pPk || IsVirtual(pTab) || iDataCur==iTabCur ); assert( pPk || IsVirtual(pTab) || iIdxCur==iDataCur+1 ); if( eOnePass==ONEPASS_MULTI ) sqlite3VdbeJumpHere(v, iAddrOnce); } /* Set up a loop over the rowids/primary-keys that were found in the ** where-clause loop above. */ if( eOnePass!=ONEPASS_OFF ){ assert( nKey==nPk ); /* OP_Found will use an unpacked key */ if( !IsVirtual(pTab) && aToOpen[iDataCur-iTabCur] ){ assert( pPk!=0 || pTab->pSelect!=0 ); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, addrBypass, iKey, nKey); VdbeCoverage(v); } }else if( pPk ){ addrLoop = sqlite3VdbeAddOp1(v, OP_Rewind, iEphCur); VdbeCoverage(v); sqlite3VdbeAddOp2(v, OP_RowKey, iEphCur, iKey); assert( nKey==0 ); /* OP_Found will use a composite key */ }else{ addrLoop = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, 0, iKey); VdbeCoverage(v); assert( nKey==1 ); } /* 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, iKey, pVTab, P4_VTAB); sqlite3VdbeChangeP5(v, OE_Abort); assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE ); sqlite3MayAbort(pParse); if( eOnePass==ONEPASS_SINGLE && sqlite3IsToplevel(pParse) ){ pParse->isMultiWrite = 0; } }else #endif { int count = (pParse->nested==0); /* True to count changes */ int iIdxNoSeek = -1; if( bComplex==0 && aiCurOnePass[1]!=iDataCur ){ iIdxNoSeek = aiCurOnePass[1]; } sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur, iKey, nKey, count, OE_Default, eOnePass, iIdxNoSeek); } /* End of the loop over all rowids/primary-keys. */ if( eOnePass!=ONEPASS_OFF ){ sqlite3VdbeResolveLabel(v, addrBypass); sqlite3WhereEnd(pWInfo); }else if( pPk ){ sqlite3VdbeAddOp2(v, OP_Next, iEphCur, addrLoop+1); VdbeCoverage(v); sqlite3VdbeJumpHere(v, addrLoop); }else{ sqlite3VdbeGoto(v, addrLoop); sqlite3VdbeJumpHere(v, addrLoop); } /* Close the cursors open on the table and its indexes. */ if( !isView && !IsVirtual(pTab) ){ if( !pPk ) sqlite3VdbeAddOp1(v, OP_Close, iDataCur); for(i=0, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){ sqlite3VdbeAddOp1(v, OP_Close, iIdxCur + i); } } } /* End non-truncate path */ /* 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); sqlite3DbFree(db, aToOpen); return; }
/* ** This function is called when a row is inserted into or deleted from the ** child table of foreign key constraint pFKey. If an SQL UPDATE is executed ** on the child table of pFKey, this function is invoked twice for each row ** affected - once to "delete" the old row, and then again to "insert" the ** new row. ** ** Each time it is called, this function generates VDBE code to locate the ** row in the parent table that corresponds to the row being inserted into ** or deleted from the child table. If the parent row can be found, no ** special action is taken. Otherwise, if the parent row can *not* be ** found in the parent table: ** ** Operation | FK type | Action taken ** -------------------------------------------------------------------------- ** INSERT immediate Increment the "immediate constraint counter". ** ** DELETE immediate Decrement the "immediate constraint counter". ** ** INSERT deferred Increment the "deferred constraint counter". ** ** DELETE deferred Decrement the "deferred constraint counter". ** ** These operations are identified in the comment at the top of this file ** (fkey.c) as "I.1" and "D.1". */ static void fkLookupParent( Parse *pParse, /* Parse context */ int iDb, /* Index of database housing pTab */ Table *pTab, /* Parent table of FK pFKey */ Index *pIdx, /* Unique index on parent key columns in pTab */ FKey *pFKey, /* Foreign key constraint */ int *aiCol, /* Map from parent key columns to child table columns */ int regData, /* Address of array containing child table row */ int nIncr, /* Increment constraint counter by this */ int isIgnore /* If true, pretend pTab contains all NULL values */ ){ int i; /* Iterator variable */ Vdbe *v = sqlite3GetVdbe(pParse); /* Vdbe to add code to */ int iCur = pParse->nTab - 1; /* Cursor number to use */ int iOk = sqlite3VdbeMakeLabel(v); /* jump here if parent key found */ /* If nIncr is less than zero, then check at runtime if there are any ** outstanding constraints to resolve. If there are not, there is no need ** to check if deleting this row resolves any outstanding violations. ** ** Check if any of the key columns in the child table row are NULL. If ** any are, then the constraint is considered satisfied. No need to ** search for a matching row in the parent table. */ if( nIncr<0 ){ sqlite3VdbeAddOp2(v, OP_FkIfZero, pFKey->isDeferred, iOk); } for(i=0; i<pFKey->nCol; i++){ int iReg = aiCol[i] + regData + 1; sqlite3VdbeAddOp2(v, OP_IsNull, iReg, iOk); } if( isIgnore==0 ){ if( pIdx==0 ){ /* If pIdx is NULL, then the parent key is the INTEGER PRIMARY KEY ** column of the parent table (table pTab). */ int iMustBeInt; /* Address of MustBeInt instruction */ int regTemp = sqlite3GetTempReg(pParse); /* Invoke MustBeInt to coerce the child key value to an integer (i.e. ** apply the affinity of the parent key). If this fails, then there ** is no matching parent key. Before using MustBeInt, make a copy of ** the value. Otherwise, the value inserted into the child key column ** will have INTEGER affinity applied to it, which may not be correct. */ sqlite3VdbeAddOp2(v, OP_SCopy, aiCol[0]+1+regData, regTemp); iMustBeInt = sqlite3VdbeAddOp2(v, OP_MustBeInt, regTemp, 0); /* If the parent table is the same as the child table, and we are about ** to increment the constraint-counter (i.e. this is an INSERT operation), ** then check if the row being inserted matches itself. If so, do not ** increment the constraint-counter. */ if( pTab==pFKey->pFrom && nIncr==1 ){ sqlite3VdbeAddOp3(v, OP_Eq, regData, iOk, regTemp); } sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead); sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regTemp); sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk); sqlite3VdbeJumpHere(v, sqlite3VdbeCurrentAddr(v)-2); sqlite3VdbeJumpHere(v, iMustBeInt); sqlite3ReleaseTempReg(pParse, regTemp); }else{ int nCol = pFKey->nCol; int regTemp = sqlite3GetTempRange(pParse, nCol); int regRec = sqlite3GetTempReg(pParse); KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); sqlite3VdbeAddOp3(v, OP_OpenRead, iCur, pIdx->tnum, iDb); sqlite3VdbeChangeP4(v, -1, (char*)pKey, P4_KEYINFO_HANDOFF); for(i=0; i<nCol; i++){ sqlite3VdbeAddOp2(v, OP_Copy, aiCol[i]+1+regData, regTemp+i); } /* If the parent table is the same as the child table, and we are about ** to increment the constraint-counter (i.e. this is an INSERT operation), ** then check if the row being inserted matches itself. If so, do not ** increment the constraint-counter. ** ** If any of the parent-key values are NULL, then the row cannot match ** itself. So set JUMPIFNULL to make sure we do the OP_Found if any ** of the parent-key values are NULL (at this point it is known that ** none of the child key values are). */ if( pTab==pFKey->pFrom && nIncr==1 ){ int iJump = sqlite3VdbeCurrentAddr(v) + nCol + 1; for(i=0; i<nCol; i++){ int iChild = aiCol[i]+1+regData; int iParent = pIdx->aiColumn[i]+1+regData; assert( aiCol[i]!=pTab->iPKey ); if( pIdx->aiColumn[i]==pTab->iPKey ){ /* The parent key is a composite key that includes the IPK column */ iParent = regData; } sqlite3VdbeAddOp3(v, OP_Ne, iChild, iJump, iParent); sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL); } sqlite3VdbeAddOp2(v, OP_Goto, 0, iOk); } sqlite3VdbeAddOp3(v, OP_MakeRecord, regTemp, nCol, regRec); sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v,pIdx), P4_TRANSIENT); sqlite3VdbeAddOp4Int(v, OP_Found, iCur, iOk, regRec, 0); sqlite3ReleaseTempReg(pParse, regRec); sqlite3ReleaseTempRange(pParse, regTemp, nCol); } } if( !pFKey->isDeferred && !pParse->pToplevel && !pParse->isMultiWrite ){ /* Special case: If this is an INSERT statement that will insert exactly ** one row into the table, raise a constraint immediately instead of ** incrementing a counter. This is necessary as the VM code is being ** generated for will not open a statement transaction. */ assert( nIncr==1 ); sqlite3HaltConstraint( pParse, OE_Abort, "foreign key constraint failed", P4_STATIC ); }else{ if( nIncr>0 && pFKey->isDeferred==0 ){ sqlite3ParseToplevel(pParse)->mayAbort = 1; } sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr); } sqlite3VdbeResolveLabel(v, iOk); sqlite3VdbeAddOp1(v, OP_Close, iCur); }
/* ** Process an UPDATE statement. ** ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; ** \_______/ \________/ \______/ \________________/ * onError pTabList pChanges pWhere */ void sqlite3Update( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table in which we should change things */ ExprList *pChanges, /* Things to be changed */ Expr *pWhere, /* The WHERE clause. May be null */ int onError /* How to handle constraint errors */ ){ int i, j; /* Loop counters */ Table *pTab; /* The table to be updated */ int addr = 0; /* VDBE instruction address of the start of the loop */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Vdbe *v; /* The virtual database engine */ Index *pIdx; /* For looping over indices */ int nIdx; /* Number of indices that need updating */ int iCur; /* VDBE Cursor number of pTab */ sqlite3 *db; /* The database structure */ int *aRegIdx = 0; /* One register assigned to each index to be updated */ int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the ** an expression for the i-th column of the table. ** aXRef[i]==-1 if the i-th column is not changed. */ int chngRowid; /* True if the record number is being changed */ Expr *pRowidExpr = 0; /* Expression defining the new record number */ int openAll = 0; /* True if all indices need to be opened */ AuthContext sContext; /* The authorization context */ NameContext sNC; /* The name-context to resolve expressions in */ int iDb; /* Database containing the table being updated */ int j1; /* Addresses of jump instructions */ int okOnePass; /* True for one-pass algorithm without the FIFO */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* Trying to update a view */ int triggers_exist = 0; /* True if any row triggers exist */ #endif int iBeginAfterTrigger = 0; /* Address of after trigger program */ int iEndAfterTrigger = 0; /* Exit of after trigger program */ int iBeginBeforeTrigger = 0; /* Address of before trigger program */ int iEndBeforeTrigger = 0; /* Exit of before trigger program */ u32 old_col_mask = 0; /* Mask of OLD.* columns in use */ u32 new_col_mask = 0; /* Mask of NEW.* columns in use */ int newIdx = -1; /* index of trigger "new" temp table */ int oldIdx = -1; /* index of trigger "old" temp table */ /* Register Allocations */ int regRowCount = 0; /* A count of rows changed */ int regOldRowid; /* The old rowid */ int regNewRowid; /* The new rowid */ int regData; /* New data for the row */ int regRowSet = 0; /* Rowset of rows to be updated */ sContext.pParse = 0; db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto update_cleanup; } assert( pTabList->nSrc==1 ); /* Locate the table which we want to update. */ pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto update_cleanup; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); /* Figure out if we have any triggers and if the table being ** updated is a view */ #ifndef SQLITE_OMIT_TRIGGER triggers_exist = sqlite3TriggersExist(pTab, TK_UPDATE, pChanges); isView = pTab->pSelect!=0; #else # define triggers_exist 0 # define isView 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){ goto update_cleanup; } if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol ); if( aXRef==0 ) goto update_cleanup; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; /* If there are FOR EACH ROW triggers, allocate cursors for the ** special OLD and NEW tables */ if( triggers_exist ){ newIdx = pParse->nTab++; oldIdx = pParse->nTab++; } /* Allocate a cursors for the main database table and for all indices. ** The index cursors might not be used, but if they are used they ** need to occur right after the database cursor. So go ahead and ** allocate enough space, just in case. */ pTabList->a[0].iCursor = iCur = pParse->nTab++; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ pParse->nTab++; } /* Initialize the name-context */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; /* Resolve the column names in all the expressions of the ** of the UPDATE statement. Also find the column index ** for each column to be updated in the pChanges array. For each ** column to be updated, make sure we have authorization to change ** that column. */ chngRowid = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( sqlite3IsRowid(pChanges->a[i].zName) ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, pTab->aCol[j].zName, db->aDb[iDb].zName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } /* Allocate memory for the array aRegIdx[]. There is one entry in the ** array for each index associated with table being updated. Fill in ** the value with a register number for indices that are to be used ** and with zero for unused indices. */ for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){} if( nIdx>0 ){ aRegIdx = sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx ); if( aRegIdx==0 ) goto update_cleanup; } for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngRowid ){ reg = ++pParse->nMem; }else{ reg = 0; for(i=0; i<pIdx->nColumn; i++){ if( aXRef[pIdx->aiColumn[i]]>=0 ){ reg = ++pParse->nMem; break; } } } aRegIdx[j] = reg; } /* Allocate a block of register used to store the change record ** sent to sqlite3GenerateConstraintChecks(). There are either ** one or two registers for holding the rowid. One rowid register ** is used if chngRowid is false and two are used if chngRowid is ** true. Following these are pTab->nCol register holding column ** data. */ regOldRowid = regNewRowid = pParse->nMem + 1; pParse->nMem += pTab->nCol + 1; if( chngRowid ){ regNewRowid++; pParse->nMem++; } regData = regNewRowid+1; /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, 1, iDb); #ifndef SQLITE_OMIT_VIRTUALTABLE /* Virtual tables must be handled separately */ if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere); pWhere = 0; pTabList = 0; goto update_cleanup; } #endif /* Start the view context */ if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } /* Generate the code for triggers. */ if( triggers_exist ){ int iGoto; /* Create pseudo-tables for NEW and OLD */ sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol); sqlite3VdbeAddOp2(v, OP_OpenPseudo, oldIdx, 0); sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol); sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0); iGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0); addr = sqlite3VdbeMakeLabel(v); iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v); if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){ goto update_cleanup; } iEndBeforeTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0); iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v); if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){ goto update_cleanup; } iEndAfterTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0); sqlite3VdbeJumpHere(v, iGoto); } /* If we are trying to update 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 all the expressions in the ** WHERE clause. */ if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } /* Begin the database scan */ sqlite3VdbeAddOp2(v, OP_Null, 0, regOldRowid); pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, WHERE_ONEPASS_DESIRED, 0); if( pWInfo==0 ) goto update_cleanup; okOnePass = pWInfo->okOnePass; /* Remember the rowid of every item to be updated. */ sqlite3VdbeAddOp2(v, IsVirtual(pTab)?OP_VRowid:OP_Rowid, iCur, regOldRowid); if( !okOnePass ){ regRowSet = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } /* End the database scan loop. */ sqlite3WhereEnd(pWInfo); /* Initialize the count of updated rows */ if( db->flags & SQLITE_CountRows && !pParse->trigStack ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } if( !isView && !IsVirtual(pTab) ){ /* ** Open every index that needs updating. Note that if any ** index could potentially invoke a REPLACE conflict resolution ** action, then we need to open all indices because we might need ** to be deleting some records. */ if( !okOnePass ) sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); if( onError==OE_Replace ){ openAll = 1; }else{ openAll = 0; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->onError==OE_Replace ){ openAll = 1; break; } } } for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ if( openAll || aRegIdx[i]>0 ){ KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); sqlite3VdbeAddOp4(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, iDb, (char*)pKey, P4_KEYINFO_HANDOFF); assert( pParse->nTab>iCur+i+1 ); } } } /* Jump back to this point if a trigger encounters an IGNORE constraint. */ if( triggers_exist ){ sqlite3VdbeResolveLabel(v, addr); } /* Top of the update loop */ if( okOnePass ){ int a1 = sqlite3VdbeAddOp1(v, OP_NotNull, regOldRowid); addr = sqlite3VdbeAddOp0(v, OP_Goto); sqlite3VdbeJumpHere(v, a1); }else{ addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, 0, regOldRowid); } if( triggers_exist ){ int regRowid; int regRow; int regCols; /* Make cursor iCur point to the record that is being updated. */ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid); /* Generate the OLD table */ regRowid = sqlite3GetTempReg(pParse); regRow = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regRowid); if( !old_col_mask ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regRow); }else{ sqlite3VdbeAddOp2(v, OP_RowData, iCur, regRow); } sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, regRow, regRowid); /* Generate the NEW table */ if( chngRowid ){ sqlite3ExprCodeAndCache(pParse, pRowidExpr, regRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regRowid); }else{ sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regRowid); } regCols = sqlite3GetTempRange(pParse, pTab->nCol); for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i); continue; } j = aXRef[i]; if( new_col_mask&((u32)1<<i) || new_col_mask==0xffffffff ){ if( j<0 ){ sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regCols+i); sqlite3ColumnDefault(v, pTab, i); }else{ sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr, regCols+i); } }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i); } } sqlite3VdbeAddOp3(v, OP_MakeRecord, regCols, pTab->nCol, regRow); if( !isView ){ sqlite3TableAffinityStr(v, pTab); sqlite3ExprCacheAffinityChange(pParse, regCols, pTab->nCol); } sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol); /* if( pParse->nErr ) goto update_cleanup; */ sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRow, regRowid); sqlite3ReleaseTempReg(pParse, regRowid); sqlite3ReleaseTempReg(pParse, regRow); sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger); sqlite3VdbeJumpHere(v, iEndBeforeTrigger); } if( !isView && !IsVirtual(pTab) ){ /* Loop over every record that needs updating. We have to load ** the old data for each record to be updated because some columns ** might not change and we will need to copy the old value. ** Also, the old data is needed to delete the old index entries. ** So make the cursor point at the old record. */ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid); /* If the record number will change, push the record number as it ** will be after the update. (The old record number is currently ** on top of the stack.) */ if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); } /* Compute new data for this record. */ for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regData+i); continue; } j = aXRef[i]; if( j<0 ){ sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regData+i); sqlite3ColumnDefault(v, pTab, i); }else{ sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regData+i); } } /* Do constraint checks */ sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid, aRegIdx, chngRowid, 1, onError, addr); /* Delete the old indices for the current record. */ j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regOldRowid); sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, aRegIdx); /* If changing the record number, delete the old record. */ if( chngRowid ){ sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0); } sqlite3VdbeJumpHere(v, j1); /* Create the new index entries and the new record. */ sqlite3CompleteInsertion(pParse, pTab, iCur, regNewRowid, aRegIdx, 1, -1, 0); } /* Increment the row counter */ if( db->flags & SQLITE_CountRows && !pParse->trigStack){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } /* If there are triggers, close all the cursors after each iteration ** through the loop. The fire the after triggers. */ if( triggers_exist ){ sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger); sqlite3VdbeJumpHere(v, iEndAfterTrigger); } /* Repeat the above with the next record to be updated, until ** all record selected by the WHERE clause have been updated. */ sqlite3VdbeAddOp2(v, OP_Goto, 0, addr); sqlite3VdbeJumpHere(v, addr); /* Close all tables */ for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ if( openAll || aRegIdx[i]>0 ){ sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0); } } sqlite3VdbeAddOp2(v, OP_Close, iCur, 0); if( triggers_exist ){ sqlite3VdbeAddOp2(v, OP_Close, newIdx, 0); sqlite3VdbeAddOp2(v, OP_Close, oldIdx, 0); } /* ** Return the number of rows that were changed. If this routine is ** generating code because of a call to sqlite3NestedParse(), do not ** invoke the callback function. */ if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aRegIdx); sqlite3DbFree(db, aXRef); sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); return; }
/* ** Generate code that will cause the most recent index analysis to ** be loaded into internal hash tables where is can be used. */ static void loadAnalysis(Parse *pParse, int iDb){ Vdbe *v = sqlite3GetVdbe(pParse); if( v ){ sqlite3VdbeAddOp1(v, OP_LoadAnalysis, iDb); } }
/* ** Generate code to do an analysis of all indices associated with ** a single table. */ static void analyzeOneTable( Parse *pParse, /* Parser context */ Table *pTab, /* Table whose indices are to be analyzed */ Index *pOnlyIdx, /* If not NULL, only analyze this one index */ int iStatCur, /* Index of VdbeCursor that writes the sqlite_stat1 table */ int iMem /* Available memory locations begin here */ ){ sqlite3 *db = pParse->db; /* Database handle */ Index *pIdx; /* An index to being analyzed */ int iIdxCur; /* Cursor open on index being analyzed */ Vdbe *v; /* The virtual machine being built up */ int i; /* Loop counter */ int topOfLoop; /* The top of the loop */ int endOfLoop; /* The end of the loop */ int jZeroRows = -1; /* Jump from here if number of rows is zero */ int iDb; /* Index of database containing pTab */ int regTabname = iMem++; /* Register containing table name */ int regIdxname = iMem++; /* Register containing index name */ int regSampleno = iMem++; /* Register containing next sample number */ int regCol = iMem++; /* Content of a column analyzed table */ int regRec = iMem++; /* Register holding completed record */ int regTemp = iMem++; /* Temporary use register */ int regRowid = iMem++; /* Rowid for the inserted record */ #ifdef SQLITE_ENABLE_STAT2 int addr = 0; /* Instruction address */ int regTemp2 = iMem++; /* Temporary use register */ int regSamplerecno = iMem++; /* Index of next sample to record */ int regRecno = iMem++; /* Current sample index */ int regLast = iMem++; /* Index of last sample to record */ int regFirst = iMem++; /* Index of first sample to record */ #endif v = sqlite3GetVdbe(pParse); if( v==0 || NEVER(pTab==0) ){ return; } if( pTab->tnum==0 ){ /* Do not gather statistics on views or virtual tables */ return; } if( memcmp(pTab->zName, "sqlite_", 7)==0 ){ /* Do not gather statistics on system tables */ return; } assert( sqlite3BtreeHoldsAllMutexes(db) ); iDb = sqlite3SchemaToIndex(db, pTab->pSchema); assert( iDb>=0 ); assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); #ifndef SQLITE_OMIT_AUTHORIZATION if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0, db->aDb[iDb].zName ) ){ return; } #endif /* Establish a read-lock on the table at the shared-cache level. */ sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); iIdxCur = pParse->nTab++; sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0); for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ int nCol; KeyInfo *pKey; if( pOnlyIdx && pOnlyIdx!=pIdx ) continue; nCol = pIdx->nColumn; pKey = sqlite3IndexKeyinfo(pParse, pIdx); if( iMem+1+(nCol*2)>pParse->nMem ){ pParse->nMem = iMem+1+(nCol*2); } /* Open a cursor to the index to be analyzed. */ assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) ); sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb, (char *)pKey, P4_KEYINFO_HANDOFF); VdbeComment((v, "%s", pIdx->zName)); /* Populate the register containing the index name. */ sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0); #ifdef SQLITE_ENABLE_STAT2 /* If this iteration of the loop is generating code to analyze the ** first index in the pTab->pIndex list, then register regLast has ** not been populated. In this case populate it now. */ if( pTab->pIndex==pIdx ){ sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regSamplerecno); sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2-1, regTemp); sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES*2, regTemp2); sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regLast); sqlite3VdbeAddOp2(v, OP_Null, 0, regFirst); addr = sqlite3VdbeAddOp3(v, OP_Lt, regSamplerecno, 0, regLast); sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regFirst); sqlite3VdbeAddOp3(v, OP_Multiply, regLast, regTemp, regLast); sqlite3VdbeAddOp2(v, OP_AddImm, regLast, SQLITE_INDEX_SAMPLES*2-2); sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regLast, regLast); sqlite3VdbeJumpHere(v, addr); } /* Zero the regSampleno and regRecno registers. */ sqlite3VdbeAddOp2(v, OP_Integer, 0, regSampleno); sqlite3VdbeAddOp2(v, OP_Integer, 0, regRecno); sqlite3VdbeAddOp2(v, OP_Copy, regFirst, regSamplerecno); #endif /* The block of memory cells initialized here is used as follows. ** ** iMem: ** The total number of rows in the table. ** ** iMem+1 .. iMem+nCol: ** Number of distinct entries in index considering the ** left-most N columns only, where N is between 1 and nCol, ** inclusive. ** ** iMem+nCol+1 .. Mem+2*nCol: ** Previous value of indexed columns, from left to right. ** ** Cells iMem through iMem+nCol are initialized to 0. The others are ** initialized to contain an SQL NULL. */ for(i=0; i<=nCol; i++){ sqlite3VdbeAddOp2(v, OP_Integer, 0, iMem+i); } for(i=0; i<nCol; i++){ sqlite3VdbeAddOp2(v, OP_Null, 0, iMem+nCol+i+1); } /* Start the analysis loop. This loop runs through all the entries in ** the index b-tree. */ endOfLoop = sqlite3VdbeMakeLabel(v); sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop); topOfLoop = sqlite3VdbeCurrentAddr(v); sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1); for(i=0; i<nCol; i++){ CollSeq *pColl; sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol); if( i==0 ){ #ifdef SQLITE_ENABLE_STAT2 /* Check if the record that cursor iIdxCur points to contains a ** value that should be stored in the sqlite_stat2 table. If so, ** store it. */ int ne = sqlite3VdbeAddOp3(v, OP_Ne, regRecno, 0, regSamplerecno); assert( regTabname+1==regIdxname && regTabname+2==regSampleno && regTabname+3==regCol ); sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL); sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 4, regRec, "aaab", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regRowid); /* Calculate new values for regSamplerecno and regSampleno. ** ** sampleno = sampleno + 1 ** samplerecno = samplerecno+(remaining records)/(remaining samples) */ sqlite3VdbeAddOp2(v, OP_AddImm, regSampleno, 1); sqlite3VdbeAddOp3(v, OP_Subtract, regRecno, regLast, regTemp); sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_INDEX_SAMPLES, regTemp2); sqlite3VdbeAddOp3(v, OP_Subtract, regSampleno, regTemp2, regTemp2); sqlite3VdbeAddOp3(v, OP_Divide, regTemp2, regTemp, regTemp); sqlite3VdbeAddOp3(v, OP_Add, regSamplerecno, regTemp, regSamplerecno); sqlite3VdbeJumpHere(v, ne); sqlite3VdbeAddOp2(v, OP_AddImm, regRecno, 1); #endif /* Always record the very first row */ sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1); } assert( pIdx->azColl!=0 ); assert( pIdx->azColl[i]!=0 ); pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]); sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1, (char*)pColl, P4_COLLSEQ); sqlite3VdbeChangeP5(v, SQLITE_NULLEQ); } if( db->mallocFailed ){ /* If a malloc failure has occurred, then the result of the expression ** passed as the second argument to the call to sqlite3VdbeJumpHere() ** below may be negative. Which causes an assert() to fail (or an ** out-of-bounds write if SQLITE_DEBUG is not defined). */ return; } sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop); for(i=0; i<nCol; i++){ int addr2 = sqlite3VdbeCurrentAddr(v) - (nCol*2); if( i==0 ){ sqlite3VdbeJumpHere(v, addr2-1); /* Set jump dest for the OP_IfNot */ } sqlite3VdbeJumpHere(v, addr2); /* Set jump dest for the OP_Ne */ sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1); sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1); } /* End of the analysis loop. */ sqlite3VdbeResolveLabel(v, endOfLoop); sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop); sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); /* Store the results in sqlite_stat1. ** ** The result is a single row of the sqlite_stat1 table. The first ** two columns are the names of the table and index. The third column ** is a string composed of a list of integer statistics about the ** index. The first integer in the list is the total number of entries ** in the index. There is one additional integer in the list for each ** column of the table. This additional integer is a guess of how many ** rows of the table the index will select. If D is the count of distinct ** values and K is the total number of rows, then the integer is computed ** as: ** ** I = (K+D-1)/D ** ** If K==0 then no entry is made into the sqlite_stat1 table. ** If K>0 then it is always the case the D>0 so division by zero ** is never possible. */ sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regSampleno); if( jZeroRows<0 ){ jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem); } for(i=0; i<nCol; i++){ sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0); sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno); sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp); sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp); sqlite3VdbeAddOp1(v, OP_ToInt, regTemp); sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regSampleno, regSampleno); } sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid); sqlite3VdbeChangeP5(v, OPFLAG_APPEND); } /* If the table has no indices, create a single sqlite_stat1 entry ** containing NULL as the index name and the row count as the content. */ if( pTab->pIndex==0 ){ sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb); VdbeComment((v, "%s", pTab->zName)); sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regSampleno); sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regSampleno); }else{ sqlite3VdbeJumpHere(v, jZeroRows); jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto); } sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname); sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regRowid); sqlite3VdbeChangeP5(v, OPFLAG_APPEND); if( pParse->nMem<regRec ) pParse->nMem = regRec; sqlite3VdbeJumpHere(v, jZeroRows); }
/* ** Generate code for an UPDATE of a virtual table. ** ** There are two possible strategies - the default and the special ** "onepass" strategy. Onepass is only used if the virtual table ** implementation indicates that pWhere may match at most one row. ** ** The default strategy is to create an ephemeral table that contains ** for each row to be changed: ** ** (A) The original rowid of that row. ** (B) The revised rowid for the row. ** (C) The content of every column in the row. ** ** Then loop through the contents of this ephemeral table executing a ** VUpdate for each row. When finished, drop the ephemeral table. ** ** The "onepass" strategy does not use an ephemeral table. Instead, it ** stores the same values (A, B and C above) in a register array and ** makes a single invocation of VUpdate. */ static void updateVirtualTable( Parse *pParse, /* The parsing context */ SrcList *pSrc, /* The virtual table to be modified */ Table *pTab, /* The virtual table */ ExprList *pChanges, /* The columns to change in the UPDATE statement */ Expr *pRowid, /* Expression used to recompute the rowid */ int *aXRef, /* Mapping from columns of pTab to entries in pChanges */ Expr *pWhere, /* WHERE clause of the UPDATE statement */ int onError /* ON CONFLICT strategy */ ){ Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */ int ephemTab; /* Table holding the result of the SELECT */ int i; /* Loop counter */ sqlite3 *db = pParse->db; /* Database connection */ const char *pVTab = (const char*)sqlite3GetVTable(db, pTab); WhereInfo *pWInfo; int nArg = 2 + pTab->nCol; /* Number of arguments to VUpdate */ int regArg; /* First register in VUpdate arg array */ int regRec; /* Register in which to assemble record */ int regRowid; /* Register for ephem table rowid */ int iCsr = pSrc->a[0].iCursor; /* Cursor used for virtual table scan */ int aDummy[2]; /* Unused arg for sqlite3WhereOkOnePass() */ int eOnePass; /* True to use onepass strategy */ int addr; /* Address of OP_OpenEphemeral */ /* Allocate nArg registers in which to gather the arguments for VUpdate. Then ** create and open the ephemeral table in which the records created from ** these arguments will be temporarily stored. */ assert( v ); ephemTab = pParse->nTab++; addr= sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, nArg); regArg = pParse->nMem + 1; pParse->nMem += nArg; regRec = ++pParse->nMem; regRowid = ++pParse->nMem; /* Start scanning the virtual table */ pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0,0,WHERE_ONEPASS_DESIRED,0); if( pWInfo==0 ) return; /* Populate the argument registers. */ for(i=0; i<pTab->nCol; i++){ if( aXRef[i]>=0 ){ sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i); }else{ sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i); sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* Enable sqlite3_vtab_nochange() */ } } if( HasRowid(pTab) ){ sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg); if( pRowid ){ sqlite3ExprCode(pParse, pRowid, regArg+1); }else{ sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg+1); } }else{ Index *pPk; /* PRIMARY KEY index */ i16 iPk; /* PRIMARY KEY column */ pPk = sqlite3PrimaryKeyIndex(pTab); assert( pPk!=0 ); assert( pPk->nKeyCol==1 ); iPk = pPk->aiColumn[0]; sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, iPk, regArg); sqlite3VdbeAddOp2(v, OP_SCopy, regArg+2+iPk, regArg+1); } eOnePass = sqlite3WhereOkOnePass(pWInfo, aDummy); /* There is no ONEPASS_MULTI on virtual tables */ assert( eOnePass==ONEPASS_OFF || eOnePass==ONEPASS_SINGLE ); if( eOnePass ){ /* If using the onepass strategy, no-op out the OP_OpenEphemeral coded ** above. */ sqlite3VdbeChangeToNoop(v, addr); sqlite3VdbeAddOp1(v, OP_Close, iCsr); }else{ /* Create a record from the argument register contents and insert it into ** the ephemeral table. */ sqlite3MultiWrite(pParse); sqlite3VdbeAddOp3(v, OP_MakeRecord, regArg, nArg, regRec); #ifdef SQLITE_DEBUG /* Signal an assert() within OP_MakeRecord that it is allowed to ** accept no-change records with serial_type 10 */ sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG_MAGIC); #endif sqlite3VdbeAddOp2(v, OP_NewRowid, ephemTab, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, ephemTab, regRec, regRowid); } if( eOnePass==ONEPASS_OFF ){ /* End the virtual table scan */ sqlite3WhereEnd(pWInfo); /* Begin scannning through the ephemeral table. */ addr = sqlite3VdbeAddOp1(v, OP_Rewind, ephemTab); VdbeCoverage(v); /* Extract arguments from the current row of the ephemeral table and ** invoke the VUpdate method. */ for(i=0; i<nArg; i++){ sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i, regArg+i); } } sqlite3VtabMakeWritable(pParse, pTab); sqlite3VdbeAddOp4(v, OP_VUpdate, 0, nArg, regArg, pVTab, P4_VTAB); sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError); sqlite3MayAbort(pParse); /* End of the ephemeral table scan. Or, if using the onepass strategy, ** jump to here if the scan visited zero rows. */ if( eOnePass==ONEPASS_OFF ){ sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); VdbeCoverage(v); sqlite3VdbeJumpHere(v, addr); sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0); }else{ sqlite3WhereEnd(pWInfo); } }
/* ** Process an UPDATE statement. ** ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; ** \_______/ \________/ \______/ \________________/ * onError pTabList pChanges pWhere */ void sqlite3Update( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table in which we should change things */ ExprList *pChanges, /* Things to be changed */ Expr *pWhere, /* The WHERE clause. May be null */ int onError /* How to handle constraint errors */ ){ int i, j; /* Loop counters */ Table *pTab; /* The table to be updated */ int addrTop = 0; /* VDBE instruction address of the start of the loop */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Vdbe *v; /* The virtual database engine */ Index *pIdx; /* For looping over indices */ Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */ int nIdx; /* Number of indices that need updating */ int iBaseCur; /* Base cursor number */ int iDataCur; /* Cursor for the canonical data btree */ int iIdxCur; /* Cursor for the first index */ sqlite3 *db; /* The database structure */ int *aRegIdx = 0; /* One register assigned to each index to be updated */ int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the ** an expression for the i-th column of the table. ** aXRef[i]==-1 if the i-th column is not changed. */ u8 *aToOpen; /* 1 for tables and indices to be opened */ u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */ u8 chngRowid; /* Rowid changed in a normal table */ u8 chngKey; /* Either chngPk or chngRowid */ Expr *pRowidExpr = 0; /* Expression defining the new record number */ AuthContext sContext; /* The authorization context */ NameContext sNC; /* The name-context to resolve expressions in */ int iDb; /* Database containing the table being updated */ int okOnePass; /* True for one-pass algorithm without the FIFO */ int hasFK; /* True if foreign key processing is required */ int labelBreak; /* Jump here to break out of UPDATE loop */ int labelContinue; /* Jump here to continue next step of UPDATE loop */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* True when updating a view (INSTEAD OF trigger) */ Trigger *pTrigger; /* List of triggers on pTab, if required */ int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ #endif int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */ int iEph = 0; /* Ephemeral table holding all primary key values */ int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */ int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */ /* Register Allocations */ int regRowCount = 0; /* A count of rows changed */ int regOldRowid = 0; /* The old rowid */ int regNewRowid = 0; /* The new rowid */ int regNew = 0; /* Content of the NEW.* table in triggers */ int regOld = 0; /* Content of OLD.* table in triggers */ int regRowSet = 0; /* Rowset of rows to be updated */ int regKey = 0; /* composite PRIMARY KEY value */ memset(&sContext, 0, sizeof(sContext)); db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto update_cleanup; } assert( pTabList->nSrc==1 ); /* Locate the table which we want to update. */ pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto update_cleanup; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); /* Figure out if we have any triggers and if the table being ** updated is a view. */ #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask); isView = pTab->pSelect!=0; assert( pTrigger || tmask==0 ); #else # define pTrigger 0 # define isView 0 # define tmask 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, tmask) ){ goto update_cleanup; } /* Allocate a cursors for the main database table and for all indices. ** The index cursors might not be used, but if they are used they ** need to occur right after the database cursor. So go ahead and ** allocate enough space, just in case. */ pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++; iIdxCur = iDataCur+1; pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab); for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ if( IsPrimaryKeyIndex(pIdx) && pPk!=0 ){ iDataCur = pParse->nTab; pTabList->a[0].iCursor = iDataCur; } pParse->nTab++; } /* Allocate space for aXRef[], aRegIdx[], and aToOpen[]. ** Initialize aXRef[] and aToOpen[] to their default values. */ aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 ); if( aXRef==0 ) goto update_cleanup; aRegIdx = aXRef+pTab->nCol; aToOpen = (u8*)(aRegIdx+nIdx); memset(aToOpen, 1, nIdx+1); aToOpen[nIdx+1] = 0; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; /* Initialize the name-context */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; /* Resolve the column names in all the expressions of the ** of the UPDATE statement. Also find the column index ** for each column to be updated in the pChanges array. For each ** column to be updated, make sure we have authorization to change ** that column. */ chngRowid = chngPk = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){ chngPk = 1; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){ j = -1; chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); pParse->checkSchema = 1; goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, j<0 ? "ROWID" : pTab->aCol[j].zName, db->aDb[iDb].zName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } assert( (chngRowid & chngPk)==0 ); assert( chngRowid==0 || chngRowid==1 ); assert( chngPk==0 || chngPk==1 ); chngKey = chngRowid + chngPk; /* The SET expressions are not actually used inside the WHERE loop. ** So reset the colUsed mask */ pTabList->a[0].colUsed = 0; hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey); /* There is one entry in the aRegIdx[] array for each index on the table ** being updated. Fill in aRegIdx[] with a register number that will hold ** the key for accessing each index. ** ** FIXME: Be smarter about omitting indexes that use expressions. */ for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){ reg = ++pParse->nMem; }else{ reg = 0; for(i=0; i<pIdx->nKeyCol; i++){ i16 iIdxCol = pIdx->aiColumn[i]; if( iIdxCol<0 || aXRef[iIdxCol]>=0 ){ reg = ++pParse->nMem; break; } } } if( reg==0 ) aToOpen[j+1] = 0; aRegIdx[j] = reg; } /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, 1, iDb); /* Allocate required registers. */ if( !IsVirtual(pTab) ){ regRowSet = ++pParse->nMem; regOldRowid = regNewRowid = ++pParse->nMem; if( chngPk || pTrigger || hasFK ){ regOld = pParse->nMem + 1; pParse->nMem += pTab->nCol; } if( chngKey || pTrigger || hasFK ){ regNewRowid = ++pParse->nMem; } regNew = pParse->nMem + 1; pParse->nMem += pTab->nCol; } /* Start the view context. */ if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } /* If we are trying to update a view, realize that view into ** an ephemeral table. */ #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur); } #endif /* Resolve the column names in all the expressions in the ** WHERE clause. */ if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } #ifndef SQLITE_OMIT_VIRTUALTABLE /* Virtual tables must be handled separately */ if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere, onError); goto update_cleanup; } #endif /* Begin the database scan */ if( HasRowid(pTab) ){ sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid); pWInfo = sqlite3WhereBegin( pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur ); if( pWInfo==0 ) goto update_cleanup; okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); /* Remember the rowid of every item to be updated. */ sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid); if( !okOnePass ){ sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } /* End the database scan loop. */ sqlite3WhereEnd(pWInfo); }else{ int iPk; /* First of nPk memory cells holding PRIMARY KEY value */ i16 nPk; /* Number of components of the PRIMARY KEY */ int addrOpen; /* Address of the OpenEphemeral instruction */ assert( pPk!=0 ); nPk = pPk->nKeyCol; iPk = pParse->nMem+1; pParse->nMem += nPk; regKey = ++pParse->nMem; iEph = pParse->nTab++; sqlite3VdbeAddOp2(v, OP_Null, 0, iPk); addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk); sqlite3VdbeSetP4KeyInfo(pParse, pPk); pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur); if( pWInfo==0 ) goto update_cleanup; okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); for(i=0; i<nPk; i++){ assert( pPk->aiColumn[i]>=0 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i], iPk+i); } if( okOnePass ){ sqlite3VdbeChangeToNoop(v, addrOpen); nKey = nPk; regKey = iPk; }else{ sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey, sqlite3IndexAffinityStr(db, pPk), nPk); sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey); } sqlite3WhereEnd(pWInfo); } /* Initialize the count of updated rows */ if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } labelBreak = sqlite3VdbeMakeLabel(v); if( !isView ){ /* ** Open every index that needs updating. Note that if any ** index could potentially invoke a REPLACE conflict resolution ** action, then we need to open all indices because we might need ** to be deleting some records. */ if( onError==OE_Replace ){ memset(aToOpen, 1, nIdx+1); }else{ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->onError==OE_Replace ){ memset(aToOpen, 1, nIdx+1); break; } } } if( okOnePass ){ if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0; if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0; } sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur, aToOpen, 0, 0); } /* Top of the update loop */ if( okOnePass ){ if( aToOpen[iDataCur-iBaseCur] && !isView ){ assert( pPk ); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey); VdbeCoverageNeverTaken(v); } labelContinue = labelBreak; sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak); VdbeCoverageIf(v, pPk==0); VdbeCoverageIf(v, pPk!=0); }else if( pPk ){ labelContinue = sqlite3VdbeMakeLabel(v); sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v); addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0); VdbeCoverage(v); }else{ labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, labelBreak, regOldRowid); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } /* If the record number will change, set register regNewRowid to ** contain the new value. If the record number is not being modified, ** then regNewRowid is the same register as regOldRowid, which is ** already populated. */ assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid ); if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v); } /* Compute the old pre-UPDATE content of the row being changed, if that ** information is needed */ if( chngPk || hasFK || pTrigger ){ u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0); oldmask |= sqlite3TriggerColmask(pParse, pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( oldmask==0xffffffff || (i<32 && (oldmask & MASKBIT32(i))!=0) || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){ testcase( oldmask!=0xffffffff && i==31 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i); } } if( chngRowid==0 && pPk==0 ){ sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid); } } /* Populate the array of registers beginning at regNew with the new ** row data. This array is used to check constants, create the new ** table and index records, and as the values for any new.* references ** made by triggers. ** ** If there are one or more BEFORE triggers, then do not populate the ** registers associated with columns that are (a) not modified by ** this UPDATE statement and (b) not accessed by new.* references. The ** values for registers not modified by the UPDATE must be reloaded from ** the database after the BEFORE triggers are fired anyway (as the trigger ** may have modified them). So not loading those that are not going to ** be used eliminates some redundant opcodes. */ newmask = sqlite3TriggerColmask( pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); }else{ j = aXRef[i]; if( j>=0 ){ sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i); }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){ /* This branch loads the value of a column that will not be changed ** into a register. This is done if there are no BEFORE triggers, or ** if there are one or more BEFORE triggers that use this value via ** a new.* reference in a trigger program. */ testcase( i==31 ); testcase( i==32 ); sqlite3ExprCodeGetColumnToReg(pParse, pTab, i, iDataCur, regNew+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); } } } /* Fire any BEFORE UPDATE triggers. This happens before constraints are ** verified. One could argue that this is wrong. */ if( tmask&TRIGGER_BEFORE ){ sqlite3TableAffinity(v, pTab, regNew); sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue); /* The row-trigger may have deleted the row being updated. In this ** case, jump to the next row. No updates or AFTER triggers are ** required. This behavior - what happens when the row being updated ** is deleted or renamed by a BEFORE trigger - is left undefined in the ** documentation. */ if( pPk ){ sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey); VdbeCoverage(v); }else{ sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } /* If it did not delete it, the row-trigger may still have modified ** some of the columns of the row being updated. Load the values for ** all columns not modified by the update statement into their ** registers in case this has happened. */ for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 && i!=pTab->iPKey ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i); } } } if( !isView ){ int addr1 = 0; /* Address of jump instruction */ int bReplace = 0; /* True if REPLACE conflict resolution might happen */ /* Do constraint checks. */ assert( regOldRowid>0 ); sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur, regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace); /* Do FK constraint checks. */ if( hasFK ){ sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey); } /* Delete the index entries associated with the current record. */ if( bReplace || chngKey ){ if( pPk ){ addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey); }else{ addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid); } VdbeCoverageNeverTaken(v); } sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1); /* If changing the record number, delete the old record. */ if( hasFK || chngKey || pPk!=0 ){ sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0); } if( bReplace || chngKey ){ sqlite3VdbeJumpHere(v, addr1); } if( hasFK ){ sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey); } /* Insert the new index entries and the new record. */ sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx, 1, 0, 0); /* 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 updated. */ if( hasFK ){ sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey); } } /* Increment the row counter */ if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue); /* Repeat the above with the next record to be updated, until ** all record selected by the WHERE clause have been updated. */ if( okOnePass ){ /* Nothing to do at end-of-loop for a single-pass */ }else if( pPk ){ sqlite3VdbeResolveLabel(v, labelContinue); sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v); }else{ sqlite3VdbeGoto(v, labelContinue); } sqlite3VdbeResolveLabel(v, labelBreak); /* Close all tables */ for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ assert( aRegIdx ); if( aToOpen[i+1] ){ sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0); } } if( iDataCur<iIdxCur ) sqlite3VdbeAddOp2(v, OP_Close, iDataCur, 0); /* 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 changed. If this routine is ** generating code because of a call to sqlite3NestedParse(), do not ** invoke the callback function. */ if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */ sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); return; }
/* ** Process an UPDATE statement. ** ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; ** \_______/ \________/ \______/ \________________/ * onError pTabList pChanges pWhere */ void sqlite3Update( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table in which we should change things */ ExprList *pChanges, /* Things to be changed */ Expr *pWhere, /* The WHERE clause. May be null */ int onError /* How to handle constraint errors */ ){ int i, j; /* Loop counters */ Table *pTab; /* The table to be updated */ int addr = 0; /* VDBE instruction address of the start of the loop */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Vdbe *v; /* The virtual database engine */ Index *pIdx; /* For looping over indices */ int nIdx; /* Number of indices that need updating */ int iCur; /* VDBE Cursor number of pTab */ sqlite3 *db; /* The database structure */ int *aRegIdx = 0; /* One register assigned to each index to be updated */ int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the ** an expression for the i-th column of the table. ** aXRef[i]==-1 if the i-th column is not changed. */ int chngRowid; /* True if the record number is being changed */ Expr *pRowidExpr = 0; /* Expression defining the new record number */ int openAll = 0; /* True if all indices need to be opened */ AuthContext sContext; /* The authorization context */ NameContext sNC; /* The name-context to resolve expressions in */ int iDb; /* Database containing the table being updated */ int okOnePass; /* True for one-pass algorithm without the FIFO */ int hasFK; /* True if foreign key processing is required */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* True when updating a view (INSTEAD OF trigger) */ Trigger *pTrigger; /* List of triggers on pTab, if required */ int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ #endif int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */ /* Register Allocations */ int regRowCount = 0; /* A count of rows changed */ int regOldRowid; /* The old rowid */ int regNewRowid; /* The new rowid */ int regNew; int regOld = 0; int regRowSet = 0; /* Rowset of rows to be updated */ int regRec; /* Register used for new table record to insert */ memset(&sContext, 0, sizeof(sContext)); db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto update_cleanup; } assert( pTabList->nSrc==1 ); /* Locate the table which we want to update. */ pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto update_cleanup; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); /* Figure out if we have any triggers and if the table being ** updated is a view. */ #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask); isView = pTab->pSelect!=0; assert( pTrigger || tmask==0 ); #else # define pTrigger 0 # define isView 0 # define tmask 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, tmask) ){ goto update_cleanup; } aXRef = sqlite3DbMallocRaw(db, sizeof(int) * pTab->nCol ); if( aXRef==0 ) goto update_cleanup; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; /* Allocate a cursors for the main database table and for all indices. ** The index cursors might not be used, but if they are used they ** need to occur right after the database cursor. So go ahead and ** allocate enough space, just in case. */ pTabList->a[0].iCursor = iCur = pParse->nTab++; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ pParse->nTab++; } /* Initialize the name-context */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; /* Resolve the column names in all the expressions of the ** of the UPDATE statement. Also find the column index ** for each column to be updated in the pChanges array. For each ** column to be updated, make sure we have authorization to change ** that column. */ chngRowid = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( sqlite3IsRowid(pChanges->a[i].zName) ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); pParse->checkSchema = 1; goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, pTab->aCol[j].zName, db->aDb[iDb].zName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngRowid); /* Allocate memory for the array aRegIdx[]. There is one entry in the ** array for each index associated with table being updated. Fill in ** the value with a register number for indices that are to be used ** and with zero for unused indices. */ for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){} if( nIdx>0 ){ aRegIdx = sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx ); if( aRegIdx==0 ) goto update_cleanup; } for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngRowid ){ reg = ++pParse->nMem; }else{ reg = 0; for(i=0; i<pIdx->nColumn; i++){ if( aXRef[pIdx->aiColumn[i]]>=0 ){ reg = ++pParse->nMem; break; } } } aRegIdx[j] = reg; } /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, 1, iDb); #ifndef SQLITE_OMIT_VIRTUALTABLE /* Virtual tables must be handled separately */ if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere); pWhere = 0; pTabList = 0; goto update_cleanup; } #endif /* Allocate required registers. */ regOldRowid = regNewRowid = ++pParse->nMem; if( pTrigger || hasFK ){ regOld = pParse->nMem + 1; pParse->nMem += pTab->nCol; } if( chngRowid || pTrigger || hasFK ){ regNewRowid = ++pParse->nMem; } regNew = pParse->nMem + 1; pParse->nMem += pTab->nCol; regRec = ++pParse->nMem; /* Start the view context. */ if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } /* If we are trying to update 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 all the expressions in the ** WHERE clause. */ if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } /* Begin the database scan */ sqlite3VdbeAddOp2(v, OP_Null, 0, regOldRowid); pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere,0, WHERE_ONEPASS_DESIRED); if( pWInfo==0 ) goto update_cleanup; okOnePass = pWInfo->okOnePass; /* Remember the rowid of every item to be updated. */ sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regOldRowid); if( !okOnePass ){ regRowSet = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } /* End the database scan loop. */ sqlite3WhereEnd(pWInfo); /* Initialize the count of updated rows */ if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } if( !isView ){ /* ** Open every index that needs updating. Note that if any ** index could potentially invoke a REPLACE conflict resolution ** action, then we need to open all indices because we might need ** to be deleting some records. */ if( !okOnePass ) sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); if( onError==OE_Replace ){ openAll = 1; }else{ openAll = 0; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->onError==OE_Replace ){ openAll = 1; break; } } } for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ if( openAll || aRegIdx[i]>0 ){ KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx); sqlite3VdbeAddOp4(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, iDb, (char*)pKey, P4_KEYINFO_HANDOFF); assert( pParse->nTab>iCur+i+1 ); } } } /* Top of the update loop */ if( okOnePass ){ int a1 = sqlite3VdbeAddOp1(v, OP_NotNull, regOldRowid); addr = sqlite3VdbeAddOp0(v, OP_Goto); sqlite3VdbeJumpHere(v, a1); }else{ addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, 0, regOldRowid); } /* Make cursor iCur point to the record that is being updated. If ** this record does not exist for some reason (deleted by a trigger, ** for example, then jump to the next iteration of the RowSet loop. */ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid); /* If the record number will change, set register regNewRowid to ** contain the new value. If the record number is not being modified, ** then regNewRowid is the same register as regOldRowid, which is ** already populated. */ assert( chngRowid || pTrigger || hasFK || regOldRowid==regNewRowid ); if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); } /* If there are triggers on this table, populate an array of registers ** with the required old.* column data. */ if( hasFK || pTrigger ){ u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0); oldmask |= sqlite3TriggerColmask(pParse, pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 || oldmask==0xffffffff || (oldmask & (1<<i)) ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, i, regOld+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i); } } if( chngRowid==0 ){ sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid); } } /* Populate the array of registers beginning at regNew with the new ** row data. This array is used to check constaints, create the new ** table and index records, and as the values for any new.* references ** made by triggers. ** ** If there are one or more BEFORE triggers, then do not populate the ** registers associated with columns that are (a) not modified by ** this UPDATE statement and (b) not accessed by new.* references. The ** values for registers not modified by the UPDATE must be reloaded from ** the database after the BEFORE triggers are fired anyway (as the trigger ** may have modified them). So not loading those that are not going to ** be used eliminates some redundant opcodes. */ newmask = sqlite3TriggerColmask( pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); }else{ j = aXRef[i]; if( j>=0 ){ sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i); }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask&(1<<i)) ){ /* This branch loads the value of a column that will not be changed ** into a register. This is done if there are no BEFORE triggers, or ** if there are one or more BEFORE triggers that use this value via ** a new.* reference in a trigger program. */ testcase( i==31 ); testcase( i==32 ); sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regNew+i); sqlite3ColumnDefault(v, pTab, i, regNew+i); } } } /* Fire any BEFORE UPDATE triggers. This happens before constraints are ** verified. One could argue that this is wrong. */ if( tmask&TRIGGER_BEFORE ){ sqlite3VdbeAddOp2(v, OP_Affinity, regNew, pTab->nCol); sqlite3TableAffinityStr(v, pTab); sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, regOldRowid, onError, addr); /* The row-trigger may have deleted the row being updated. In this ** case, jump to the next row. No updates or AFTER triggers are ** required. This behaviour - what happens when the row being updated ** is deleted or renamed by a BEFORE trigger - is left undefined in the ** documentation. */ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid); /* If it did not delete it, the row-trigger may still have modified ** some of the columns of the row being updated. Load the values for ** all columns not modified by the update statement into their ** registers in case this has happened. */ for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 && i!=pTab->iPKey ){ sqlite3VdbeAddOp3(v, OP_Column, iCur, i, regNew+i); sqlite3ColumnDefault(v, pTab, i, regNew+i); } } } if( !isView ){ int j1; /* Address of jump instruction */ /* Do constraint checks. */ sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid, aRegIdx, (chngRowid?regOldRowid:0), 1, onError, addr, 0); /* Do FK constraint checks. */ if( hasFK ){ sqlite3FkCheck(pParse, pTab, regOldRowid, 0); } /* Delete the index entries associated with the current record. */ j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, regOldRowid); sqlite3GenerateRowIndexDelete(pParse, pTab, iCur, aRegIdx); /* If changing the record number, delete the old record. */ if( hasFK || chngRowid ){ sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0); } sqlite3VdbeJumpHere(v, j1); if( hasFK ){ sqlite3FkCheck(pParse, pTab, 0, regNewRowid); } /* Insert the new index entries and the new record. */ sqlite3CompleteInsertion(pParse, pTab, iCur, regNewRowid, aRegIdx, 1, 0, 0); /* 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 updated. */ if( hasFK ){ sqlite3FkActions(pParse, pTab, pChanges, regOldRowid); } } /* Increment the row counter */ if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, regOldRowid, onError, addr); /* Repeat the above with the next record to be updated, until ** all record selected by the WHERE clause have been updated. */ sqlite3VdbeAddOp2(v, OP_Goto, 0, addr); sqlite3VdbeJumpHere(v, addr); /* Close all tables */ for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ if( openAll || aRegIdx[i]>0 ){ sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0); } } sqlite3VdbeAddOp2(v, OP_Close, iCur, 0); /* 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 changed. If this routine is ** generating code because of a call to sqlite3NestedParse(), do not ** invoke the callback function. */ if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aRegIdx); sqlite3DbFree(db, aXRef); sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); return; }
/* ** This procedure generates VDBE code for a single invocation of either the ** sqlite_detach() or sqlite_attach() SQL user functions. */ static void codeAttach( Parse *pParse, /* The parser context */ int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */ FuncDef *pFunc, /* FuncDef wrapper for detachFunc() or attachFunc() */ Expr *pAuthArg, /* Expression to pass to authorization callback */ Expr *pFilename, /* Name of database file */ Expr *pDbname, /* Name of the database to use internally */ Expr *pKey /* Database key for encryption extension */ ){ int rc; NameContext sName; Vdbe *v; sqlite3* db = pParse->db; int regArgs; memset(&sName, 0, sizeof(NameContext)); sName.pParse = pParse; if( SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) || SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) || SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey)) ){ pParse->nErr++; goto attach_end; } #ifndef SQLITE_OMIT_AUTHORIZATION if( pAuthArg ){ char *zAuthArg = pAuthArg->u.zToken; if( NEVER(zAuthArg==0) ){ goto attach_end; } rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0); if(rc!=SQLITE_OK ){ goto attach_end; } } #endif /* SQLITE_OMIT_AUTHORIZATION */ v = sqlite3GetVdbe(pParse); regArgs = sqlite3GetTempRange(pParse, 4); sqlite3ExprCode(pParse, pFilename, regArgs); sqlite3ExprCode(pParse, pDbname, regArgs+1); sqlite3ExprCode(pParse, pKey, regArgs+2); assert( v || db->mallocFailed ); if( v ){ sqlite3VdbeAddOp3(v, OP_Function, 0, regArgs+3-pFunc->nArg, regArgs+3); assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg ); sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg)); sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF); /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this ** statement only). For DETACH, set it to false (expire all existing ** statements). */ sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH)); } attach_end: sqlite3ExprDelete(db, pFilename); sqlite3ExprDelete(db, pDbname); sqlite3ExprDelete(db, pKey); }
/* ** 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 */ int oldIdx = -1; /* Cursor for the OLD table of AFTER triggers */ 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 */ int triggers_exist = 0; /* True if any triggers exist */ #endif int iBeginAfterTrigger = 0; /* Address of after trigger program */ int iEndAfterTrigger = 0; /* Exit of after trigger program */ int iBeginBeforeTrigger = 0; /* Address of before trigger program */ int iEndBeforeTrigger = 0; /* Exit of before trigger program */ u32 old_col_mask = 0; /* Mask of OLD.* columns in use */ sContext.pParse = 0; 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 triggers_exist = sqlite3TriggersExist(pTab, TK_DELETE, 0); isView = pTab->pSelect!=0; #else # define triggers_exist 0 # define isView 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif if( sqlite3IsReadOnly(pParse, pTab, triggers_exist) ){ 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 || triggers_exist); /* If pTab is really a view, make sure it has been initialized. */ if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto delete_from_cleanup; } /* Allocate a cursor used to store the old.* data for a trigger. */ if( triggers_exist ){ oldIdx = pParse->nTab++; } /* 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, triggers_exist, iDb); if( triggers_exist ){ int orconf = ((pParse->trigStack)?pParse->trigStack->orconf:OE_Default); int iGoto = sqlite3VdbeAddOp0(v, OP_Goto); addr = sqlite3VdbeMakeLabel(v); iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v); (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0); iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto); iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v); (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1, oldIdx, orconf, addr, &old_col_mask, 0); iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto); sqlite3VdbeJumpHere(v, iGoto); } /* 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. Note, however, that ** this means that the row change count will be incorrect. */ if( rcauth==SQLITE_OK && pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){ assert( !isView ); sqlite3VdbeAddOp3(v, OP_Clear, pTab->tnum, iDb, memCnt); if( !pParse->nested ){ sqlite3VdbeChangeP4(v, -1, 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 iRowid = ++pParse->nMem; /* Used for storing rowid values. */ int iRowSet = ++pParse->nMem; /* Register for rowset of rows to delete */ /* Begin the database scan */ pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0); if( pWInfo==0 ) goto delete_from_cleanup; /* Remember the rowid of every item to be deleted. */ sqlite3VdbeAddOp2(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, iRowid); sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iRowid); if( db->flags & SQLITE_CountRows ){ sqlite3VdbeAddOp2(v, OP_AddImm, memCnt, 1); } /* End the database scan loop. */ sqlite3WhereEnd(pWInfo); /* Open the pseudo-table used to store OLD if there are triggers. */ if( triggers_exist ){ sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, pTab->nCol); sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx); } /* 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); if( !isView ){ /* Open cursors for the table we are deleting from and ** all its indices. */ sqlite3OpenTableAndIndices(pParse, pTab, iCur, OP_OpenWrite); } /* This is the beginning of the delete loop. If a trigger encounters ** an IGNORE constraint, it jumps back to here. */ if( triggers_exist ){ sqlite3VdbeResolveLabel(v, addr); } addr = sqlite3VdbeAddOp3(v, OP_RowSetRead, iRowSet, end, iRowid); if( triggers_exist ){ int iData = ++pParse->nMem; /* For storing row data of OLD table */ /* If the record is no longer present in the table, jump to the ** next iteration of the loop through the contents of the fifo. */ sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, iRowid); /* Populate the OLD.* pseudo-table */ if( old_col_mask ){ sqlite3VdbeAddOp2(v, OP_RowData, iCur, iData); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, iData); } sqlite3VdbeAddOp3(v, OP_Insert, oldIdx, iData, iRowid); /* Jump back and run the BEFORE triggers */ sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger); sqlite3VdbeJumpHere(v, iEndBeforeTrigger); } if( !isView ){ /* Delete the row */ #ifndef SQLITE_OMIT_VIRTUALTABLE if( IsVirtual(pTab) ){ const char *pVtab = (const char *)pTab->pVtab; sqlite3VtabMakeWritable(pParse, pTab); sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB); }else #endif { sqlite3GenerateRowDelete(pParse, pTab, iCur, iRowid, pParse->nested==0); } } /* If there are row triggers, close all cursors then invoke ** the AFTER triggers */ if( triggers_exist ){ /* Jump back and run the AFTER triggers */ sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger); sqlite3VdbeJumpHere(v, iEndAfterTrigger); } /* End of the delete loop */ sqlite3VdbeAddOp2(v, OP_Goto, 0, addr); sqlite3VdbeResolveLabel(v, end); /* Close the cursors after the loop if there are no row triggers */ 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); } } /* ** 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==0 && !pParse->trigStack ){ 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; }
/* ** This routine generates VDBE code that causes a single row of a ** single table to be deleted. Both the original table entry and ** all indices are removed. ** ** Preconditions: ** ** 1. iDataCur is an open cursor on the btree that is the canonical data ** store for the table. (This will be either the table itself, ** in the case of a rowid table, or the PRIMARY KEY index in the case ** of a WITHOUT ROWID table.) ** ** 2. Read/write cursors for all indices of pTab must be open as ** cursor number iIdxCur+i for the i-th index. ** ** 3. The primary key for the row to be deleted must be stored in a ** sequence of nPk memory cells starting at iPk. If nPk==0 that means ** that a search record formed from OP_MakeRecord is contained in the ** single memory location iPk. ** ** eMode: ** Parameter eMode may be passed either ONEPASS_OFF (0), ONEPASS_SINGLE, or ** ONEPASS_MULTI. If eMode is not ONEPASS_OFF, then the cursor ** iDataCur already points to the row to delete. If eMode is ONEPASS_OFF ** then this function must seek iDataCur to the entry identified by iPk ** and nPk before reading from it. ** ** If eMode is ONEPASS_MULTI, then this call is being made as part ** of a ONEPASS delete that affects multiple rows. In this case, if ** iIdxNoSeek is a valid cursor number (>=0), then its position should ** be preserved following the delete operation. Or, if iIdxNoSeek is not ** a valid cursor number, the position of iDataCur should be preserved ** instead. ** ** iIdxNoSeek: ** If iIdxNoSeek is a valid cursor number (>=0), then it identifies an ** index cursor (from within array of cursors starting at iIdxCur) that ** already points to the index entry to be deleted. */ void sqlite3GenerateRowDelete( Parse *pParse, /* Parsing context */ Table *pTab, /* Table containing the row to be deleted */ Trigger *pTrigger, /* List of triggers to (potentially) fire */ int iDataCur, /* Cursor from which column data is extracted */ int iIdxCur, /* First index cursor */ int iPk, /* First memory cell containing the PRIMARY KEY */ i16 nPk, /* Number of PRIMARY KEY memory cells */ u8 count, /* If non-zero, increment the row change counter */ u8 onconf, /* Default ON CONFLICT policy for triggers */ u8 eMode, /* ONEPASS_OFF, _SINGLE, or _MULTI. See above */ int iIdxNoSeek /* Cursor number of cursor that does not need seeking */ ){ Vdbe *v = pParse->pVdbe; /* Vdbe */ int iOld = 0; /* First register in OLD.* array */ int iLabel; /* Label resolved to end of generated code */ u8 opSeek; /* Seek opcode */ /* Vdbe is guaranteed to have been allocated by this stage. */ assert( v ); VdbeModuleComment((v, "BEGIN: GenRowDel(%d,%d,%d,%d)", iDataCur, iIdxCur, iPk, (int)nPk)); /* 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); opSeek = HasRowid(pTab) ? OP_NotExists : OP_NotFound; if( eMode==ONEPASS_OFF ){ sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk); VdbeCoverageIf(v, opSeek==OP_NotExists); VdbeCoverageIf(v, opSeek==OP_NotFound); } /* 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.* */ int addrStart; /* Start of BEFORE trigger programs */ /* 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, iPk, iOld); for(iCol=0; iCol<pTab->nCol; iCol++){ testcase( mask!=0xffffffff && iCol==31 ); testcase( mask!=0xffffffff && iCol==32 ); if( mask==0xffffffff || (iCol<=31 && (mask & MASKBIT32(iCol))!=0) ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, iCol, iOld+iCol+1); } } /* Invoke BEFORE DELETE trigger programs. */ addrStart = sqlite3VdbeCurrentAddr(v); sqlite3CodeRowTrigger(pParse, pTrigger, TK_DELETE, 0, TRIGGER_BEFORE, pTab, iOld, onconf, iLabel ); /* If any BEFORE triggers were coded, then seek the cursor to the ** row to be deleted again. It may be that the BEFORE triggers moved ** the cursor or of already deleted the row that the cursor was ** pointing to. */ if( addrStart<sqlite3VdbeCurrentAddr(v) ){ sqlite3VdbeAddOp4Int(v, opSeek, iDataCur, iLabel, iPk, nPk); VdbeCoverageIf(v, opSeek==OP_NotExists); VdbeCoverageIf(v, opSeek==OP_NotFound); } /* 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, 0, 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 variable 'count' is non-zero, then this OP_Delete instruction should ** invoke the update-hook. The pre-update-hook, on the other hand should ** be invoked unless table pTab is a system table. The difference is that ** the update-hook is not invoked for rows removed by REPLACE, but the ** pre-update-hook is. */ if( pTab->pSelect==0 ){ u8 p5 = 0; sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur,0,iIdxNoSeek); sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0)); sqlite3VdbeChangeP4(v, -1, (char*)pTab, P4_TABLE); if( eMode!=ONEPASS_OFF ){ sqlite3VdbeChangeP5(v, OPFLAG_AUXDELETE); } if( iIdxNoSeek>=0 ){ sqlite3VdbeAddOp1(v, OP_Delete, iIdxNoSeek); } if( eMode==ONEPASS_MULTI ) p5 |= OPFLAG_SAVEPOSITION; sqlite3VdbeChangeP5(v, p5); } /* 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, 0, 0); /* 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); VdbeModuleComment((v, "END: GenRowDel()")); }
/* ** Process a pragma statement. ** ** Pragmas are of this form: ** ** PRAGMA [database.]id [= value] ** ** The identifier might also be a string. The value is a string, and ** identifier, or a number. If minusFlag is true, then the value is ** a number that was preceded by a minus sign. ** ** If the left side is "database.id" then pId1 is the database name ** and pId2 is the id. If the left side is just "id" then pId1 is the ** id and pId2 is any empty string. */ void sqlite3Pragma( Parse *pParse, Token *pId1, /* First part of [database.]id field */ Token *pId2, /* Second part of [database.]id field, or NULL */ Token *pValue, /* Token for <value>, or NULL */ int minusFlag /* True if a '-' sign preceded <value> */ ){ char *zLeft = 0; /* Nul-terminated UTF-8 string <id> */ char *zRight = 0; /* Nul-terminated UTF-8 string <value>, or NULL */ const char *zDb = 0; /* The database name */ Token *pId; /* Pointer to <id> token */ int iDb; /* Database index for <database> */ sqlite3 *db = pParse->db; Db *pDb; Vdbe *v = pParse->pVdbe = sqlite3VdbeCreate(db); if( v==0 ) return; pParse->nMem = 2; /* Interpret the [database.] part of the pragma statement. iDb is the ** index of the database this pragma is being applied to in db.aDb[]. */ iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId); if( iDb<0 ) return; pDb = &db->aDb[iDb]; /* If the temp database has been explicitly named as part of the ** pragma, make sure it is open. */ if( iDb==1 && sqlite3OpenTempDatabase(pParse) ){ return; } zLeft = sqlite3NameFromToken(db, pId); if( !zLeft ) return; if( minusFlag ){ zRight = sqlite3MPrintf(db, "-%T", pValue); }else{ zRight = sqlite3NameFromToken(db, pValue); } zDb = ((pId2 && pId2->n>0)?pDb->zName:0); if( sqlite3AuthCheck(pParse, SQLITE_PRAGMA, zLeft, zRight, zDb) ){ goto pragma_out; } #ifndef SQLITE_OMIT_PAGER_PRAGMAS /* ** PRAGMA [database.]default_cache_size ** PRAGMA [database.]default_cache_size=N ** ** The first form reports the current persistent setting for the ** page cache size. The value returned is the maximum number of ** pages in the page cache. The second form sets both the current ** page cache size value and the persistent page cache size value ** stored in the database file. ** ** The default cache size is stored in meta-value 2 of page 1 of the ** database file. The cache size is actually the absolute value of ** this memory location. The sign of meta-value 2 determines the ** synchronous setting. A negative value means synchronous is off ** and a positive value means synchronous is on. */ if( sqlite3StrICmp(zLeft,"default_cache_size")==0 ){ static const VdbeOpList getCacheSize[] = { { OP_ReadCookie, 0, 1, 2}, /* 0 */ { OP_IfPos, 1, 6, 0}, { OP_Integer, 0, 2, 0}, { OP_Subtract, 1, 2, 1}, { OP_IfPos, 1, 6, 0}, { OP_Integer, 0, 1, 0}, /* 5 */ { OP_ResultRow, 1, 1, 0}, }; int addr; if( sqlite3ReadSchema(pParse) ) goto pragma_out; sqlite3VdbeUsesBtree(v, iDb); if( !zRight ){ sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", P4_STATIC); pParse->nMem += 2; addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize); sqlite3VdbeChangeP1(v, addr, iDb); sqlite3VdbeChangeP1(v, addr+5, SQLITE_DEFAULT_CACHE_SIZE); }else{ int size = atoi(zRight); if( size<0 ) size = -size; sqlite3BeginWriteOperation(pParse, 0, iDb); sqlite3VdbeAddOp2(v, OP_Integer, size, 1); sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, 2, 2); addr = sqlite3VdbeAddOp2(v, OP_IfPos, 2, 0); sqlite3VdbeAddOp2(v, OP_Integer, -size, 1); sqlite3VdbeJumpHere(v, addr); sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 2, 1); pDb->pSchema->cache_size = size; sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size); } }else /* ** PRAGMA [database.]page_size ** PRAGMA [database.]page_size=N ** ** The first form reports the current setting for the ** database page size in bytes. The second form sets the ** database page size value. The value can only be set if ** the database has not yet been created. */ if( sqlite3StrICmp(zLeft,"page_size")==0 ){ Btree *pBt = pDb->pBt; if( !zRight ){ int size = pBt ? sqlite3BtreeGetPageSize(pBt) : 0; returnSingleInt(pParse, "page_size", size); }else{ /* Malloc may fail when setting the page-size, as there is an internal ** buffer that the pager module resizes using sqlite3_realloc(). */ db->nextPagesize = atoi(zRight); if( SQLITE_NOMEM==sqlite3BtreeSetPageSize(pBt, db->nextPagesize, -1) ){ db->mallocFailed = 1; } } }else /* ** PRAGMA [database.]max_page_count ** PRAGMA [database.]max_page_count=N ** ** The first form reports the current setting for the ** maximum number of pages in the database file. The ** second form attempts to change this setting. Both ** forms return the current setting. */ if( sqlite3StrICmp(zLeft,"max_page_count")==0 ){ Btree *pBt = pDb->pBt; int newMax = 0; if( zRight ){ newMax = atoi(zRight); } if( pBt ){ newMax = sqlite3BtreeMaxPageCount(pBt, newMax); } returnSingleInt(pParse, "max_page_count", newMax); }else /* ** PRAGMA [database.]page_count ** ** Return the number of pages in the specified database. */ if( sqlite3StrICmp(zLeft,"page_count")==0 ){ Vdbe *v; int iReg; v = sqlite3GetVdbe(pParse); if( !v || sqlite3ReadSchema(pParse) ) goto pragma_out; sqlite3CodeVerifySchema(pParse, iDb); iReg = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Pagecount, iDb, iReg); sqlite3VdbeAddOp2(v, OP_ResultRow, iReg, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "page_count", P4_STATIC); }else /* ** PRAGMA [database.]locking_mode ** PRAGMA [database.]locking_mode = (normal|exclusive) */ if( sqlite3StrICmp(zLeft,"locking_mode")==0 ){ const char *zRet = "normal"; int eMode = getLockingMode(zRight); if( pId2->n==0 && eMode==PAGER_LOCKINGMODE_QUERY ){ /* Simple "PRAGMA locking_mode;" statement. This is a query for ** the current default locking mode (which may be different to ** the locking-mode of the main database). */ eMode = db->dfltLockMode; }else{ Pager *pPager; if( pId2->n==0 ){ /* This indicates that no database name was specified as part ** of the PRAGMA command. In this case the locking-mode must be ** set on all attached databases, as well as the main db file. ** ** Also, the sqlite3.dfltLockMode variable is set so that ** any subsequently attached databases also use the specified ** locking mode. */ int ii; assert(pDb==&db->aDb[0]); for(ii=2; ii<db->nDb; ii++){ pPager = sqlite3BtreePager(db->aDb[ii].pBt); sqlite3PagerLockingMode(pPager, eMode); } db->dfltLockMode = eMode; } pPager = sqlite3BtreePager(pDb->pBt); eMode = sqlite3PagerLockingMode(pPager, eMode); } assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE); if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){ zRet = "exclusive"; } sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P4_STATIC); sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, zRet, 0); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1); }else /* ** PRAGMA [database.]journal_mode ** PRAGMA [database.]journal_mode = (delete|persist|off) */ if( sqlite3StrICmp(zLeft,"journal_mode")==0 ){ int eMode; static char * const azModeName[] = {"delete", "persist", "off", "truncate"}; if( zRight==0 ){ eMode = PAGER_JOURNALMODE_QUERY; }else{ int n = strlen(zRight); eMode = sizeof(azModeName)/sizeof(azModeName[0]) - 1; while( eMode>=0 && sqlite3StrNICmp(zRight, azModeName[eMode], n)!=0 ){ eMode--; } } if( pId2->n==0 && eMode==PAGER_JOURNALMODE_QUERY ){ /* Simple "PRAGMA journal_mode;" statement. This is a query for ** the current default journal mode (which may be different to ** the journal-mode of the main database). */ eMode = db->dfltJournalMode; }else{ Pager *pPager; if( pId2->n==0 ){ /* This indicates that no database name was specified as part ** of the PRAGMA command. In this case the journal-mode must be ** set on all attached databases, as well as the main db file. ** ** Also, the sqlite3.dfltJournalMode variable is set so that ** any subsequently attached databases also use the specified ** journal mode. */ int ii; assert(pDb==&db->aDb[0]); for(ii=1; ii<db->nDb; ii++){ if( db->aDb[ii].pBt ){ pPager = sqlite3BtreePager(db->aDb[ii].pBt); sqlite3PagerJournalMode(pPager, eMode); } } db->dfltJournalMode = eMode; } pPager = sqlite3BtreePager(pDb->pBt); eMode = sqlite3PagerJournalMode(pPager, eMode); } assert( eMode==PAGER_JOURNALMODE_DELETE || eMode==PAGER_JOURNALMODE_TRUNCATE || eMode==PAGER_JOURNALMODE_PERSIST || eMode==PAGER_JOURNALMODE_OFF ); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "journal_mode", P4_STATIC); sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, azModeName[eMode], P4_STATIC); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1); }else /* ** PRAGMA [database.]journal_size_limit ** PRAGMA [database.]journal_size_limit=N ** ** Get or set the (boolean) value of the database 'auto-vacuum' parameter. */ if( sqlite3StrICmp(zLeft,"journal_size_limit")==0 ){ Pager *pPager = sqlite3BtreePager(pDb->pBt); i64 iLimit = -2; if( zRight ){ int iLimit32 = atoi(zRight); if( iLimit32<-1 ){ iLimit32 = -1; } iLimit = iLimit32; } iLimit = sqlite3PagerJournalSizeLimit(pPager, iLimit); returnSingleInt(pParse, "journal_size_limit", (int)iLimit); }else #endif /* SQLITE_OMIT_PAGER_PRAGMAS */ /* ** PRAGMA [database.]auto_vacuum ** PRAGMA [database.]auto_vacuum=N ** ** Get or set the (boolean) value of the database 'auto-vacuum' parameter. */ #ifndef SQLITE_OMIT_AUTOVACUUM if( sqlite3StrICmp(zLeft,"auto_vacuum")==0 ){ Btree *pBt = pDb->pBt; if( sqlite3ReadSchema(pParse) ){ goto pragma_out; } if( !zRight ){ int auto_vacuum = pBt ? sqlite3BtreeGetAutoVacuum(pBt) : SQLITE_DEFAULT_AUTOVACUUM; returnSingleInt(pParse, "auto_vacuum", auto_vacuum); }else{ int eAuto = getAutoVacuum(zRight); db->nextAutovac = eAuto; if( eAuto>=0 ){ /* Call SetAutoVacuum() to set initialize the internal auto and ** incr-vacuum flags. This is required in case this connection ** creates the database file. It is important that it is created ** as an auto-vacuum capable db. */ int rc = sqlite3BtreeSetAutoVacuum(pBt, eAuto); if( rc==SQLITE_OK && (eAuto==1 || eAuto==2) ){ /* When setting the auto_vacuum mode to either "full" or ** "incremental", write the value of meta[6] in the database ** file. Before writing to meta[6], check that meta[3] indicates ** that this really is an auto-vacuum capable database. */ static const VdbeOpList setMeta6[] = { { OP_Transaction, 0, 1, 0}, /* 0 */ { OP_ReadCookie, 0, 1, 3}, /* 1 */ { OP_If, 1, 0, 0}, /* 2 */ { OP_Halt, SQLITE_OK, OE_Abort, 0}, /* 3 */ { OP_Integer, 0, 1, 0}, /* 4 */ { OP_SetCookie, 0, 6, 1}, /* 5 */ }; int iAddr; iAddr = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6); sqlite3VdbeChangeP1(v, iAddr, iDb); sqlite3VdbeChangeP1(v, iAddr+1, iDb); sqlite3VdbeChangeP2(v, iAddr+2, iAddr+4); sqlite3VdbeChangeP1(v, iAddr+4, eAuto-1); sqlite3VdbeChangeP1(v, iAddr+5, iDb); sqlite3VdbeUsesBtree(v, iDb); } } } }else #endif /* ** PRAGMA [database.]incremental_vacuum(N) ** ** Do N steps of incremental vacuuming on a database. */ #ifndef SQLITE_OMIT_AUTOVACUUM if( sqlite3StrICmp(zLeft,"incremental_vacuum")==0 ){ int iLimit, addr; if( sqlite3ReadSchema(pParse) ){ goto pragma_out; } if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){ iLimit = 0x7fffffff; } sqlite3BeginWriteOperation(pParse, 0, iDb); sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1); addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb); sqlite3VdbeAddOp1(v, OP_ResultRow, 1); sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr); sqlite3VdbeJumpHere(v, addr); }else #endif #ifndef SQLITE_OMIT_PAGER_PRAGMAS /* ** PRAGMA [database.]cache_size ** PRAGMA [database.]cache_size=N ** ** The first form reports the current local setting for the ** page cache size. The local setting can be different from ** the persistent cache size value that is stored in the database ** file itself. The value returned is the maximum number of ** pages in the page cache. The second form sets the local ** page cache size value. It does not change the persistent ** cache size stored on the disk so the cache size will revert ** to its default value when the database is closed and reopened. ** N should be a positive integer. */ if( sqlite3StrICmp(zLeft,"cache_size")==0 ){ if( sqlite3ReadSchema(pParse) ) goto pragma_out; if( !zRight ){ returnSingleInt(pParse, "cache_size", pDb->pSchema->cache_size); }else{ int size = atoi(zRight); if( size<0 ) size = -size; pDb->pSchema->cache_size = size; sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size); } }else /* ** PRAGMA temp_store ** PRAGMA temp_store = "default"|"memory"|"file" ** ** Return or set the local value of the temp_store flag. Changing ** the local value does not make changes to the disk file and the default ** value will be restored the next time the database is opened. ** ** Note that it is possible for the library compile-time options to ** override this setting */ if( sqlite3StrICmp(zLeft, "temp_store")==0 ){ if( !zRight ){ returnSingleInt(pParse, "temp_store", db->temp_store); }else{ changeTempStorage(pParse, zRight); } }else /* ** PRAGMA temp_store_directory ** PRAGMA temp_store_directory = ""|"directory_name" ** ** Return or set the local value of the temp_store_directory flag. Changing ** the value sets a specific directory to be used for temporary files. ** Setting to a null string reverts to the default temporary directory search. ** If temporary directory is changed, then invalidateTempStorage. ** */ if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){ if( !zRight ){ if( sqlite3_temp_directory ){ sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "temp_store_directory", P4_STATIC); sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, sqlite3_temp_directory, 0); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1); } }else{ #ifndef SQLITE_OMIT_WSD if( zRight[0] ){ int rc; int res; rc = sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE, &res); if( rc!=SQLITE_OK || res==0 ){ sqlite3ErrorMsg(pParse, "not a writable directory"); goto pragma_out; } } if( SQLITE_TEMP_STORE==0 || (SQLITE_TEMP_STORE==1 && db->temp_store<=1) || (SQLITE_TEMP_STORE==2 && db->temp_store==1) ){ invalidateTempStorage(pParse); } sqlite3_free(sqlite3_temp_directory); if( zRight[0] ){ sqlite3_temp_directory = sqlite3DbStrDup(0, zRight); }else{ sqlite3_temp_directory = 0; } #endif /* SQLITE_OMIT_WSD */ } }else /* ** PRAGMA [database.]synchronous ** PRAGMA [database.]synchronous=OFF|ON|NORMAL|FULL ** ** Return or set the local value of the synchronous flag. Changing ** the local value does not make changes to the disk file and the ** default value will be restored the next time the database is ** opened. */ if( sqlite3StrICmp(zLeft,"synchronous")==0 ){ if( sqlite3ReadSchema(pParse) ) goto pragma_out; if( !zRight ){ returnSingleInt(pParse, "synchronous", pDb->safety_level-1); }else{ if( !db->autoCommit ){ sqlite3ErrorMsg(pParse, "Safety level may not be changed inside a transaction"); }else{ pDb->safety_level = getSafetyLevel(zRight)+1; } } }else #endif /* SQLITE_OMIT_PAGER_PRAGMAS */ #ifndef SQLITE_OMIT_FLAG_PRAGMAS if( flagPragma(pParse, zLeft, zRight) ){ /* The flagPragma() subroutine also generates any necessary code ** there is nothing more to do here */ }else #endif /* SQLITE_OMIT_FLAG_PRAGMAS */ #ifndef SQLITE_OMIT_SCHEMA_PRAGMAS /* ** PRAGMA table_info(<table>) ** ** Return a single row for each column of the named table. The columns of ** the returned data set are: ** ** cid: Column id (numbered from left to right, starting at 0) ** name: Column name ** type: Column declaration type. ** notnull: True if 'NOT NULL' is part of column declaration ** dflt_value: The default value for the column, if any. */ if( sqlite3StrICmp(zLeft, "table_info")==0 && zRight ){ Table *pTab; if( sqlite3ReadSchema(pParse) ) goto pragma_out; pTab = sqlite3FindTable(db, zRight, zDb); if( pTab ){ int i; int nHidden = 0; Column *pCol; sqlite3VdbeSetNumCols(v, 6); pParse->nMem = 6; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC); sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P4_STATIC); sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P4_STATIC); sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P4_STATIC); sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P4_STATIC); sqlite3ViewGetColumnNames(pParse, pTab); for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){ const Token *pDflt; if( IsHiddenColumn(pCol) ){ nHidden++; continue; } sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 1); sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pCol->zName, 0); sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pCol->zType ? pCol->zType : "", 0); sqlite3VdbeAddOp2(v, OP_Integer, pCol->notNull, 4); if( pCol->pDflt && (pDflt = &pCol->pDflt->span)->z ){ sqlite3VdbeAddOp4(v, OP_String8, 0, 5, 0, (char*)pDflt->z, pDflt->n); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, 5); } sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 6); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 6); } } }else if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){ Index *pIdx; Table *pTab; if( sqlite3ReadSchema(pParse) ) goto pragma_out; pIdx = sqlite3FindIndex(db, zRight, zDb); if( pIdx ){ int i; pTab = pIdx->pTable; sqlite3VdbeSetNumCols(v, 3); pParse->nMem = 3; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P4_STATIC); sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P4_STATIC); for(i=0; i<pIdx->nColumn; i++){ int cnum = pIdx->aiColumn[i]; sqlite3VdbeAddOp2(v, OP_Integer, i, 1); sqlite3VdbeAddOp2(v, OP_Integer, cnum, 2); assert( pTab->nCol>cnum ); sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pTab->aCol[cnum].zName, 0); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3); } } }else if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){ Index *pIdx; Table *pTab; if( sqlite3ReadSchema(pParse) ) goto pragma_out; pTab = sqlite3FindTable(db, zRight, zDb); if( pTab ){ v = sqlite3GetVdbe(pParse); pIdx = pTab->pIndex; if( pIdx ){ int i = 0; sqlite3VdbeSetNumCols(v, 3); pParse->nMem = 3; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC); sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P4_STATIC); while(pIdx){ sqlite3VdbeAddOp2(v, OP_Integer, i, 1); sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pIdx->zName, 0); sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 3); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3); ++i; pIdx = pIdx->pNext; } } } }else if( sqlite3StrICmp(zLeft, "database_list")==0 ){ int i; if( sqlite3ReadSchema(pParse) ) goto pragma_out; sqlite3VdbeSetNumCols(v, 3); pParse->nMem = 3; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC); sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P4_STATIC); for(i=0; i<db->nDb; i++){ if( db->aDb[i].pBt==0 ) continue; assert( db->aDb[i].zName!=0 ); sqlite3VdbeAddOp2(v, OP_Integer, i, 1); sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, db->aDb[i].zName, 0); sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, sqlite3BtreeGetFilename(db->aDb[i].pBt), 0); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 3); } }else if( sqlite3StrICmp(zLeft, "collation_list")==0 ){ int i = 0; HashElem *p; sqlite3VdbeSetNumCols(v, 2); pParse->nMem = 2; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC); for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){ CollSeq *pColl = (CollSeq *)sqliteHashData(p); sqlite3VdbeAddOp2(v, OP_Integer, i++, 1); sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, pColl->zName, 0); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2); } }else #endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */ #ifndef SQLITE_OMIT_FOREIGN_KEY if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){ FKey *pFK; Table *pTab; if( sqlite3ReadSchema(pParse) ) goto pragma_out; pTab = sqlite3FindTable(db, zRight, zDb); if( pTab ){ v = sqlite3GetVdbe(pParse); pFK = pTab->pFKey; if( pFK ){ int i = 0; sqlite3VdbeSetNumCols(v, 5); pParse->nMem = 5; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P4_STATIC); sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P4_STATIC); sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P4_STATIC); sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P4_STATIC); while(pFK){ int j; for(j=0; j<pFK->nCol; j++){ char *zCol = pFK->aCol[j].zCol; sqlite3VdbeAddOp2(v, OP_Integer, i, 1); sqlite3VdbeAddOp2(v, OP_Integer, j, 2); sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pFK->zTo, 0); sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0, pTab->aCol[pFK->aCol[j].iFrom].zName, 0); sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 5, 0, zCol, 0); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 5); } ++i; pFK = pFK->pNextFrom; } } } }else #endif /* !defined(SQLITE_OMIT_FOREIGN_KEY) */ #ifndef NDEBUG if( sqlite3StrICmp(zLeft, "parser_trace")==0 ){ if( zRight ){ if( getBoolean(zRight) ){ sqlite3ParserTrace(stderr, "parser: "); }else{ sqlite3ParserTrace(0, 0); } } }else #endif /* Reinstall the LIKE and GLOB functions. The variant of LIKE ** used will be case sensitive or not depending on the RHS. */ if( sqlite3StrICmp(zLeft, "case_sensitive_like")==0 ){ if( zRight ){ sqlite3RegisterLikeFunctions(db, getBoolean(zRight)); } }else #ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX # define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100 #endif #ifndef SQLITE_OMIT_INTEGRITY_CHECK /* Pragma "quick_check" is an experimental reduced version of ** integrity_check designed to detect most database corruption ** without most of the overhead of a full integrity-check. */ if( sqlite3StrICmp(zLeft, "integrity_check")==0 || sqlite3StrICmp(zLeft, "quick_check")==0 ){ int i, j, addr, mxErr; /* Code that appears at the end of the integrity check. If no error ** messages have been generated, output OK. Otherwise output the ** error message */ static const VdbeOpList endCode[] = { { OP_AddImm, 1, 0, 0}, /* 0 */ { OP_IfNeg, 1, 0, 0}, /* 1 */ { OP_String8, 0, 3, 0}, /* 2 */ { OP_ResultRow, 3, 1, 0}, }; int isQuick = (zLeft[0]=='q'); /* Initialize the VDBE program */ if( sqlite3ReadSchema(pParse) ) goto pragma_out; pParse->nMem = 6; sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P4_STATIC); /* Set the maximum error count */ mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX; if( zRight ){ mxErr = atoi(zRight); if( mxErr<=0 ){ mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX; } } sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1); /* reg[1] holds errors left */ /* Do an integrity check on each database file */ for(i=0; i<db->nDb; i++){ HashElem *x; Hash *pTbls; int cnt = 0; if( OMIT_TEMPDB && i==1 ) continue; sqlite3CodeVerifySchema(pParse, i); addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */ sqlite3VdbeAddOp2(v, OP_Halt, 0, 0); sqlite3VdbeJumpHere(v, addr); /* Do an integrity check of the B-Tree ** ** Begin by filling registers 2, 3, ... with the root pages numbers ** for all tables and indices in the database. */ pTbls = &db->aDb[i].pSchema->tblHash; for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){ Table *pTab = sqliteHashData(x); Index *pIdx; sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt); cnt++; for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt); cnt++; } } if( cnt==0 ) continue; /* Make sure sufficient number of registers have been allocated */ if( pParse->nMem < cnt+4 ){ pParse->nMem = cnt+4; } /* Do the b-tree integrity checks */ sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1); sqlite3VdbeChangeP5(v, i); addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName), P4_DYNAMIC); sqlite3VdbeAddOp3(v, OP_Move, 2, 4, 1); sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 2); sqlite3VdbeAddOp2(v, OP_ResultRow, 2, 1); sqlite3VdbeJumpHere(v, addr); /* Make sure all the indices are constructed correctly. */ for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){ Table *pTab = sqliteHashData(x); Index *pIdx; int loopTop; if( pTab->pIndex==0 ) continue; addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Stop if out of errors */ sqlite3VdbeAddOp2(v, OP_Halt, 0, 0); sqlite3VdbeJumpHere(v, addr); sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead); sqlite3VdbeAddOp2(v, OP_Integer, 0, 2); /* reg(2) will count entries */ loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0); sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1); /* increment entry count */ for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int jmp2; static const VdbeOpList idxErr[] = { { OP_AddImm, 1, -1, 0}, { OP_String8, 0, 3, 0}, /* 1 */ { OP_Rowid, 1, 4, 0}, { OP_String8, 0, 5, 0}, /* 3 */ { OP_String8, 0, 6, 0}, /* 4 */ { OP_Concat, 4, 3, 3}, { OP_Concat, 5, 3, 3}, { OP_Concat, 6, 3, 3}, { OP_ResultRow, 3, 1, 0}, { OP_IfPos, 1, 0, 0}, /* 9 */ { OP_Halt, 0, 0, 0}, }; sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 1); jmp2 = sqlite3VdbeAddOp3(v, OP_Found, j+2, 0, 3); addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr); sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC); sqlite3VdbeChangeP4(v, addr+3, " missing from index ", P4_STATIC); sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_STATIC); sqlite3VdbeJumpHere(v, addr+9); sqlite3VdbeJumpHere(v, jmp2); } sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1); sqlite3VdbeJumpHere(v, loopTop); for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ static const VdbeOpList cntIdx[] = { { OP_Integer, 0, 3, 0}, { OP_Rewind, 0, 0, 0}, /* 1 */ { OP_AddImm, 3, 1, 0}, { OP_Next, 0, 0, 0}, /* 3 */ { OP_Eq, 2, 0, 3}, /* 4 */ { OP_AddImm, 1, -1, 0}, { OP_String8, 0, 2, 0}, /* 6 */ { OP_String8, 0, 3, 0}, /* 7 */ { OP_Concat, 3, 2, 2}, { OP_ResultRow, 2, 1, 0}, }; if( pIdx->tnum==0 ) continue; addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); sqlite3VdbeAddOp2(v, OP_Halt, 0, 0); sqlite3VdbeJumpHere(v, addr); addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx); sqlite3VdbeChangeP1(v, addr+1, j+2); sqlite3VdbeChangeP2(v, addr+1, addr+4); sqlite3VdbeChangeP1(v, addr+3, j+2); sqlite3VdbeChangeP2(v, addr+3, addr+2); sqlite3VdbeJumpHere(v, addr+4); sqlite3VdbeChangeP4(v, addr+6, "wrong # of entries in index ", P4_STATIC); sqlite3VdbeChangeP4(v, addr+7, pIdx->zName, P4_STATIC); } } } addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode); sqlite3VdbeChangeP2(v, addr, -mxErr); sqlite3VdbeJumpHere(v, addr+1); sqlite3VdbeChangeP4(v, addr+2, "ok", P4_STATIC); }else #endif /* SQLITE_OMIT_INTEGRITY_CHECK */ #ifndef SQLITE_OMIT_UTF16 /* ** PRAGMA encoding ** PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be" ** ** In its first form, this pragma returns the encoding of the main ** database. If the database is not initialized, it is initialized now. ** ** The second form of this pragma is a no-op if the main database file ** has not already been initialized. In this case it sets the default ** encoding that will be used for the main database file if a new file ** is created. If an existing main database file is opened, then the ** default text encoding for the existing database is used. ** ** In all cases new databases created using the ATTACH command are ** created to use the same default text encoding as the main database. If ** the main database has not been initialized and/or created when ATTACH ** is executed, this is done before the ATTACH operation. ** ** In the second form this pragma sets the text encoding to be used in ** new database files created using this database handle. It is only ** useful if invoked immediately after the main database i */ if( sqlite3StrICmp(zLeft, "encoding")==0 ){ static const struct EncName { char *zName; u8 enc; } encnames[] = { { "UTF-8", SQLITE_UTF8 }, { "UTF8", SQLITE_UTF8 }, { "UTF-16le", SQLITE_UTF16LE }, { "UTF16le", SQLITE_UTF16LE }, { "UTF-16be", SQLITE_UTF16BE }, { "UTF16be", SQLITE_UTF16BE }, { "UTF-16", 0 }, /* SQLITE_UTF16NATIVE */ { "UTF16", 0 }, /* SQLITE_UTF16NATIVE */ { 0, 0 } }; const struct EncName *pEnc; if( !zRight ){ /* "PRAGMA encoding" */ if( sqlite3ReadSchema(pParse) ) goto pragma_out; sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P4_STATIC); sqlite3VdbeAddOp2(v, OP_String8, 0, 1); for(pEnc=&encnames[0]; pEnc->zName; pEnc++){ if( pEnc->enc==ENC(pParse->db) ){ sqlite3VdbeChangeP4(v, -1, pEnc->zName, P4_STATIC); break; } } sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 1); }else{ /* "PRAGMA encoding = XXX" */ /* Only change the value of sqlite.enc if the database handle is not ** initialized. If the main database exists, the new sqlite.enc value ** will be overwritten when the schema is next loaded. If it does not ** already exists, it will be created to use the new encoding value. */ if( !(DbHasProperty(db, 0, DB_SchemaLoaded)) || DbHasProperty(db, 0, DB_Empty) ){ for(pEnc=&encnames[0]; pEnc->zName; pEnc++){ if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){ ENC(pParse->db) = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE; break; } } if( !pEnc->zName ){ sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight); } } } }else #endif /* SQLITE_OMIT_UTF16 */ #ifndef SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS /* ** PRAGMA [database.]schema_version ** PRAGMA [database.]schema_version = <integer> ** ** PRAGMA [database.]user_version ** PRAGMA [database.]user_version = <integer> ** ** The pragma's schema_version and user_version are used to set or get ** the value of the schema-version and user-version, respectively. Both ** the schema-version and the user-version are 32-bit signed integers ** stored in the database header. ** ** The schema-cookie is usually only manipulated internally by SQLite. It ** is incremented by SQLite whenever the database schema is modified (by ** creating or dropping a table or index). The schema version is used by ** SQLite each time a query is executed to ensure that the internal cache ** of the schema used when compiling the SQL query matches the schema of ** the database against which the compiled query is actually executed. ** Subverting this mechanism by using "PRAGMA schema_version" to modify ** the schema-version is potentially dangerous and may lead to program ** crashes or database corruption. Use with caution! ** ** The user-version is not used internally by SQLite. It may be used by ** applications for any purpose. */ if( sqlite3StrICmp(zLeft, "schema_version")==0 || sqlite3StrICmp(zLeft, "user_version")==0 || sqlite3StrICmp(zLeft, "freelist_count")==0 ){ int iCookie; /* Cookie index. 0 for schema-cookie, 6 for user-cookie. */ sqlite3VdbeUsesBtree(v, iDb); switch( zLeft[0] ){ case 's': case 'S': iCookie = 0; break; case 'f': case 'F': iCookie = 1; iDb = (-1*(iDb+1)); assert(iDb<=0); break; default: iCookie = 5; break; } if( zRight && iDb>=0 ){ /* Write the specified cookie value */ static const VdbeOpList setCookie[] = { { OP_Transaction, 0, 1, 0}, /* 0 */ { OP_Integer, 0, 1, 0}, /* 1 */ { OP_SetCookie, 0, 0, 1}, /* 2 */ }; int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie); sqlite3VdbeChangeP1(v, addr, iDb); sqlite3VdbeChangeP1(v, addr+1, atoi(zRight)); sqlite3VdbeChangeP1(v, addr+2, iDb); sqlite3VdbeChangeP2(v, addr+2, iCookie); }else{ /* Read the specified cookie value */ static const VdbeOpList readCookie[] = { { OP_ReadCookie, 0, 1, 0}, /* 0 */ { OP_ResultRow, 1, 1, 0} }; int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie); sqlite3VdbeChangeP1(v, addr, iDb); sqlite3VdbeChangeP3(v, addr, iCookie); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, P4_TRANSIENT); } }else #endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */ #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) /* ** Report the current state of file logs for all databases */ if( sqlite3StrICmp(zLeft, "lock_status")==0 ){ static const char *const azLockName[] = { "unlocked", "shared", "reserved", "pending", "exclusive" }; int i; Vdbe *v = sqlite3GetVdbe(pParse); sqlite3VdbeSetNumCols(v, 2); pParse->nMem = 2; sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P4_STATIC); sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P4_STATIC); for(i=0; i<db->nDb; i++){ Btree *pBt; Pager *pPager; const char *zState = "unknown"; int j; if( db->aDb[i].zName==0 ) continue; sqlite3VdbeAddOp4(v, OP_String8, 0, 1, 0, db->aDb[i].zName, P4_STATIC); pBt = db->aDb[i].pBt; if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){ zState = "closed"; }else if( sqlite3_file_control(db, i ? db->aDb[i].zName : 0, SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){ zState = azLockName[j]; } sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, zState, P4_STATIC); sqlite3VdbeAddOp2(v, OP_ResultRow, 1, 2); } }else #endif #ifdef SQLITE_SSE /* ** Check to see if the sqlite_statements table exists. Create it ** if it does not. */ if( sqlite3StrICmp(zLeft, "create_sqlite_statement_table")==0 ){ extern int sqlite3CreateStatementsTable(Parse*); sqlite3CreateStatementsTable(pParse); }else #endif #if SQLITE_HAS_CODEC if( sqlite3StrICmp(zLeft, "key")==0 ){ sqlite3_key(db, zRight, strlen(zRight)); }else #endif #if SQLITE_HAS_CODEC || defined(SQLITE_ENABLE_CEROD) if( sqlite3StrICmp(zLeft, "activate_extensions")==0 ){ #if SQLITE_HAS_CODEC if( sqlite3StrNICmp(zRight, "see-", 4)==0 ){ extern void sqlite3_activate_see(const char*); sqlite3_activate_see(&zRight[4]); } #endif #ifdef SQLITE_ENABLE_CEROD if( sqlite3StrNICmp(zRight, "cerod-", 6)==0 ){ extern void sqlite3_activate_cerod(const char*); sqlite3_activate_cerod(&zRight[6]); } #endif } #endif {} if( v ){ /* Code an OP_Expire at the end of each PRAGMA program to cause ** the VDBE implementing the pragma to expire. Most (all?) pragmas ** are only valid for a single execution. */ sqlite3VdbeAddOp2(v, OP_Expire, 1, 0); /* ** Reset the safety level, in case the fullfsync flag or synchronous ** setting changed. */ #ifndef SQLITE_OMIT_PAGER_PRAGMAS if( db->autoCommit ){ sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level, (db->flags&SQLITE_FullFSync)!=0); } #endif } pragma_out: sqlite3DbFree(db, zLeft); sqlite3DbFree(db, zRight); }