/* ** The parser calls this routine after the CREATE VIRTUAL TABLE statement ** has been completely parsed. */ void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){ Table *pTab = pParse->pNewTable; /* The table being constructed */ sqlite3 *db = pParse->db; /* The database connection */ if( pTab==0 ) return; addArgumentToVtab(pParse); pParse->sArg.z = 0; if( pTab->nModuleArg<1 ) return; /* If the CREATE VIRTUAL TABLE statement is being entered for the ** first time (in other words if the virtual table is actually being ** created now instead of just being read out of sqlite_master) then ** do additional initialization work and store the statement text ** in the sqlite_master table. */ if( !db->init.busy ){ char *zStmt; char *zWhere; int iDb; int iReg; Vdbe *v; /* Compute the complete text of the CREATE VIRTUAL TABLE statement */ if( pEnd ){ pParse->sNameToken.n = (int)(pEnd->z - pParse->sNameToken.z) + pEnd->n; } zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken); /* A slot for the record has already been allocated in the ** SQLITE_MASTER table. We just need to update that slot with all ** the information we've collected. ** ** The VM register number pParse->regRowid holds the rowid of an ** entry in the sqlite_master table tht was created for this vtab ** by sqlite3StartTable(). */ iDb = sqlite3SchemaToIndex(db, pTab->pSchema); sqlite3NestedParse(pParse, "UPDATE %Q.%s " "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q " "WHERE rowid=#%d", db->aDb[iDb].zDbSName, MASTER_NAME, pTab->zName, pTab->zName, zStmt, pParse->regRowid ); sqlite3DbFree(db, zStmt); v = sqlite3GetVdbe(pParse); sqlite3ChangeCookie(pParse, iDb); sqlite3VdbeAddOp0(v, OP_Expire); zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName); sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere); iReg = ++pParse->nMem; sqlite3VdbeLoadString(v, iReg, pTab->zName); sqlite3VdbeAddOp2(v, OP_VCreate, iDb, iReg); } /* If we are rereading the sqlite_master table create the in-memory ** record of the table. The xConnect() method is not called until ** the first time the virtual table is used in an SQL statement. This ** allows a schema that contains virtual tables to be loaded before ** the required virtual table implementations are registered. */ else { Table *pOld; Schema *pSchema = pTab->pSchema; const char *zName = pTab->zName; assert( sqlite3SchemaMutexHeld(db, 0, pSchema) ); pOld = sqlite3HashInsert(&pSchema->tblHash, zName, pTab); if( pOld ){ sqlite3OomFault(db); assert( pTab==pOld ); /* Malloc must have failed inside HashInsert() */ return; } pParse->pNewTable = 0; } }
/* ** 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; }
/* ** Generate VDBE code for the statements inside the body of a single ** trigger. */ static int codeTriggerProgram( Parse *pParse, /* The parser context */ TriggerStep *pStepList, /* List of statements inside the trigger body */ int orconf /* Conflict algorithm. (OE_Abort, etc) */ ){ TriggerStep *pStep; Vdbe *v = pParse->pVdbe; sqlite3 *db = pParse->db; assert( pParse->pTriggerTab && pParse->pToplevel ); assert( pStepList ); assert( v!=0 ); for(pStep=pStepList; pStep; pStep=pStep->pNext){ /* Figure out the ON CONFLICT policy that will be used for this step ** of the trigger program. If the statement that caused this trigger ** to fire had an explicit ON CONFLICT, then use it. Otherwise, use ** the ON CONFLICT policy that was specified as part of the trigger ** step statement. Example: ** ** CREATE TRIGGER AFTER INSERT ON t1 BEGIN; ** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b); ** END; ** ** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy ** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy */ pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf; /* Clear the cookieGoto flag. When coding triggers, the cookieGoto ** variable is used as a flag to indicate to sqlite3ExprCodeConstants() ** that it is not safe to refactor constants (this happens after the ** start of the first loop in the SQL statement is coded - at that ** point code may be conditionally executed, so it is no longer safe to ** initialize constant register values). */ assert( pParse->cookieGoto==0 || pParse->cookieGoto==-1 ); pParse->cookieGoto = 0; switch( pStep->op ){ case TK_UPDATE: { sqlite3Update(pParse, targetSrcList(pParse, pStep), sqlite3ExprListDup(db, pStep->pExprList, 0), sqlite3ExprDup(db, pStep->pWhere, 0), pParse->eOrconf ); break; } case TK_INSERT: { sqlite3Insert(pParse, targetSrcList(pParse, pStep), sqlite3ExprListDup(db, pStep->pExprList, 0), sqlite3SelectDup(db, pStep->pSelect, 0), sqlite3IdListDup(db, pStep->pIdList), pParse->eOrconf ); break; } case TK_DELETE: { sqlite3DeleteFrom(pParse, targetSrcList(pParse, pStep), sqlite3ExprDup(db, pStep->pWhere, 0) ); break; } default: assert( pStep->op==TK_SELECT ); { SelectDest sDest; Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0); sqlite3SelectDestInit(&sDest, SRT_Discard, 0); sqlite3Select(pParse, pSelect, &sDest); sqlite3SelectDelete(db, pSelect); break; } } if( pStep->op!=TK_SELECT ){ sqlite3VdbeAddOp0(v, OP_ResetCount); } } return 0; }
/* ** Create and populate a new TriggerPrg object with a sub-program ** implementing trigger pTrigger with ON CONFLICT policy orconf. */ static TriggerPrg *codeRowTrigger( Parse *pParse, /* Current parse context */ Trigger *pTrigger, /* Trigger to code */ Table *pTab, /* The table pTrigger is attached to */ int orconf /* ON CONFLICT policy to code trigger program with */ ){ Parse *pTop = sqlite3ParseToplevel(pParse); sqlite3 *db = pParse->db; /* Database handle */ TriggerPrg *pPrg; /* Value to return */ Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */ Vdbe *v; /* Temporary VM */ NameContext sNC; /* Name context for sub-vdbe */ SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */ Parse *pSubParse; /* Parse context for sub-vdbe */ int iEndTrigger = 0; /* Label to jump to if WHEN is false */ assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) ); assert( pTop->pVdbe ); /* Allocate the TriggerPrg and SubProgram objects. To ensure that they ** are freed if an error occurs, link them into the Parse.pTriggerPrg ** list of the top-level Parse object sooner rather than later. */ pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg)); if( !pPrg ) return 0; pPrg->pNext = pTop->pTriggerPrg; pTop->pTriggerPrg = pPrg; pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram)); if( !pProgram ) return 0; sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram); pPrg->pTrigger = pTrigger; pPrg->orconf = orconf; pPrg->aColmask[0] = 0xffffffff; pPrg->aColmask[1] = 0xffffffff; /* Allocate and populate a new Parse context to use for coding the ** trigger sub-program. */ pSubParse = sqlite3StackAllocZero(db, sizeof(Parse)); if( !pSubParse ) return 0; memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pSubParse; pSubParse->db = db; pSubParse->pTriggerTab = pTab; pSubParse->pToplevel = pTop; pSubParse->zAuthContext = pTrigger->zName; pSubParse->eTriggerOp = pTrigger->op; pSubParse->nQueryLoop = pParse->nQueryLoop; v = sqlite3GetVdbe(pSubParse); if( v ){ VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", pTrigger->zName, onErrorText(orconf), (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"), (pTrigger->op==TK_UPDATE ? "UPDATE" : ""), (pTrigger->op==TK_INSERT ? "INSERT" : ""), (pTrigger->op==TK_DELETE ? "DELETE" : ""), pTab->zName )); #ifndef SQLITE_OMIT_TRACE sqlite3VdbeChangeP4(v, -1, sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC ); #endif /* If one was specified, code the WHEN clause. If it evaluates to false ** (or NULL) the sub-vdbe is immediately halted by jumping to the ** OP_Halt inserted at the end of the program. */ if( pTrigger->pWhen ){ pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0); if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) && db->mallocFailed==0 ){ iEndTrigger = sqlite3VdbeMakeLabel(v); sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL); } sqlite3ExprDelete(db, pWhen); } /* Code the trigger program into the sub-vdbe. */ codeTriggerProgram(pSubParse, pTrigger->step_list, orconf); /* Insert an OP_Halt at the end of the sub-program. */ if( iEndTrigger ){ sqlite3VdbeResolveLabel(v, iEndTrigger); } sqlite3VdbeAddOp0(v, OP_Halt); VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf))); transferParseError(pParse, pSubParse); if( db->mallocFailed==0 ){ pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg); } pProgram->nMem = pSubParse->nMem; pProgram->nCsr = pSubParse->nTab; pProgram->nOnce = pSubParse->nOnce; pProgram->token = (void *)pTrigger; pPrg->aColmask[0] = pSubParse->oldmask; pPrg->aColmask[1] = pSubParse->newmask; sqlite3VdbeDelete(v); } assert( !pSubParse->pAinc && !pSubParse->pZombieTab ); assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg ); sqlite3StackFree(db, pSubParse); return pPrg; }
/* ** 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; }
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; }
/* ** 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; }
/* ** Generate VDBE code for the statements inside the body of a single ** trigger. */ static int codeTriggerProgram( Parse *pParse, /* The parser context */ TriggerStep *pStepList, /* List of statements inside the trigger body */ int orconf /* Conflict algorithm. (OE_Abort, etc) */ ){ TriggerStep *pStep; Vdbe *v = pParse->pVdbe; sqlite3 *db = pParse->db; assert( pParse->pTriggerTab && pParse->pToplevel ); assert( pStepList ); assert( v!=0 ); for(pStep=pStepList; pStep; pStep=pStep->pNext){ /* Figure out the ON CONFLICT policy that will be used for this step ** of the trigger program. If the statement that caused this trigger ** to fire had an explicit ON CONFLICT, then use it. Otherwise, use ** the ON CONFLICT policy that was specified as part of the trigger ** step statement. Example: ** ** CREATE TRIGGER AFTER INSERT ON t1 BEGIN; ** INSERT OR REPLACE INTO t2 VALUES(new.a, new.b); ** END; ** ** INSERT INTO t1 ... ; -- insert into t2 uses REPLACE policy ** INSERT OR IGNORE INTO t1 ... ; -- insert into t2 uses IGNORE policy */ pParse->eOrconf = (orconf==OE_Default)?pStep->orconf:(u8)orconf; assert( pParse->okConstFactor==0 ); switch( pStep->op ){ case TK_UPDATE: { sqlite3Update(pParse, targetSrcList(pParse, pStep), sqlite3ExprListDup(db, pStep->pExprList, 0), sqlite3ExprDup(db, pStep->pWhere, 0), pParse->eOrconf ); break; } case TK_INSERT: { sqlite3Insert(pParse, targetSrcList(pParse, pStep), sqlite3SelectDup(db, pStep->pSelect, 0), sqlite3IdListDup(db, pStep->pIdList), pParse->eOrconf ); break; } case TK_DELETE: { sqlite3DeleteFrom(pParse, targetSrcList(pParse, pStep), sqlite3ExprDup(db, pStep->pWhere, 0) ); break; } default: assert( pStep->op==TK_SELECT ); { SelectDest sDest; Select *pSelect = sqlite3SelectDup(db, pStep->pSelect, 0); sqlite3SelectDestInit(&sDest, SRT_Discard, 0); sqlite3Select(pParse, pSelect, &sDest); sqlite3SelectDelete(db, pSelect); break; } } if( pStep->op!=TK_SELECT ){ sqlite3VdbeAddOp0(v, OP_ResetCount); } } return 0; }
/* ** 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 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); }
/* ** 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; }