/* ** Generate an expression tree to implement the WHERE, ORDER BY, ** and LIMIT/OFFSET portion of DELETE and UPDATE statements. ** ** DELETE FROM table_wxyz WHERE a<5 ORDER BY a LIMIT 1; ** \__________________________/ ** pLimitWhere (pInClause) */ Expr *sqlite3LimitWhere( Parse *pParse, /* The parser context */ SrcList *pSrc, /* the FROM clause -- which tables to scan */ Expr *pWhere, /* The WHERE clause. May be null */ ExprList *pOrderBy, /* The ORDER BY clause. May be null */ Expr *pLimit, /* The LIMIT clause. May be null */ Expr *pOffset, /* The OFFSET clause. May be null */ char *zStmtType /* Either DELETE or UPDATE. For error messages. */ ){ Expr *pWhereRowid = NULL; /* WHERE rowid .. */ Expr *pInClause = NULL; /* WHERE rowid IN ( select ) */ Expr *pSelectRowid = NULL; /* SELECT rowid ... */ ExprList *pEList = NULL; /* Expression list contaning only pSelectRowid */ SrcList *pSelectSrc = NULL; /* SELECT rowid FROM x ... (dup of pSrc) */ Select *pSelect = NULL; /* Complete SELECT tree */ /* Check that there isn't an ORDER BY without a LIMIT clause. */ if( pOrderBy && (pLimit == 0) ) { sqlite3ErrorMsg(pParse, "ORDER BY without LIMIT on %s", zStmtType); goto limit_where_cleanup_2; } /* We only need to generate a select expression if there ** is a limit/offset term to enforce. */ if( pLimit == 0 ) { /* if pLimit is null, pOffset will always be null as well. */ assert( pOffset == 0 ); return pWhere; } /* Generate a select expression tree to enforce the limit/offset ** term for the DELETE or UPDATE statement. For example: ** DELETE FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1 ** becomes: ** DELETE FROM table_a WHERE rowid IN ( ** SELECT rowid FROM table_a WHERE col1=1 ORDER BY col2 LIMIT 1 OFFSET 1 ** ); */ pSelectRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0); if( pSelectRowid == 0 ) goto limit_where_cleanup_2; pEList = sqlite3ExprListAppend(pParse, 0, pSelectRowid); if( pEList == 0 ) goto limit_where_cleanup_2; /* duplicate the FROM clause as it is needed by both the DELETE/UPDATE tree ** and the SELECT subtree. */ pSelectSrc = sqlite3SrcListDup(pParse->db, pSrc, 0); if( pSelectSrc == 0 ) { sqlite3ExprListDelete(pParse->db, pEList); goto limit_where_cleanup_2; } /* generate the SELECT expression tree. */ pSelect = sqlite3SelectNew(pParse,pEList,pSelectSrc,pWhere,0,0, pOrderBy,0,pLimit,pOffset); if( pSelect == 0 ) return 0; /* now generate the new WHERE rowid IN clause for the DELETE/UDPATE */ pWhereRowid = sqlite3PExpr(pParse, TK_ROW, 0, 0, 0); if( pWhereRowid == 0 ) goto limit_where_cleanup_1; pInClause = sqlite3PExpr(pParse, TK_IN, pWhereRowid, 0, 0); if( pInClause == 0 ) goto limit_where_cleanup_1; pInClause->x.pSelect = pSelect; pInClause->flags |= EP_xIsSelect; sqlite3ExprSetHeight(pParse, pInClause); return pInClause; /* something went wrong. clean up anything allocated. */ limit_where_cleanup_1: sqlite3SelectDelete(pParse->db, pSelect); return 0; limit_where_cleanup_2: sqlite3ExprDelete(pParse->db, pWhere); sqlite3ExprListDelete(pParse->db, pOrderBy); sqlite3ExprDelete(pParse->db, pLimit); sqlite3ExprDelete(pParse->db, pOffset); return 0; }
/* ** Process an UPDATE statement. ** ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; ** \_______/ \________/ \______/ \________________/ * onError pTabList pChanges pWhere */ void sqlite3Update( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table in which we should change things */ ExprList *pChanges, /* Things to be changed */ Expr *pWhere, /* The WHERE clause. May be null */ int onError /* How to handle constraint errors */ ){ int i, j; /* Loop counters */ Table *pTab; /* The table to be updated */ int addrTop = 0; /* VDBE instruction address of the start of the loop */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Vdbe *v; /* The virtual database engine */ Index *pIdx; /* For looping over indices */ Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */ int nIdx; /* Number of indices that need updating */ int iBaseCur; /* Base cursor number */ int iDataCur; /* Cursor for the canonical data btree */ int iIdxCur; /* Cursor for the first index */ sqlite3 *db; /* The database structure */ int *aRegIdx = 0; /* One register assigned to each index to be updated */ int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the ** an expression for the i-th column of the table. ** aXRef[i]==-1 if the i-th column is not changed. */ u8 *aToOpen; /* 1 for tables and indices to be opened */ u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */ u8 chngRowid; /* Rowid changed in a normal table */ u8 chngKey; /* Either chngPk or chngRowid */ Expr *pRowidExpr = 0; /* Expression defining the new record number */ AuthContext sContext; /* The authorization context */ NameContext sNC; /* The name-context to resolve expressions in */ int iDb; /* Database containing the table being updated */ int okOnePass; /* True for one-pass algorithm without the FIFO */ int hasFK; /* True if foreign key processing is required */ int labelBreak; /* Jump here to break out of UPDATE loop */ int labelContinue; /* Jump here to continue next step of UPDATE loop */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* True when updating a view (INSTEAD OF trigger) */ Trigger *pTrigger; /* List of triggers on pTab, if required */ int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ #endif int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */ int iEph = 0; /* Ephemeral table holding all primary key values */ int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */ int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */ /* Register Allocations */ int regRowCount = 0; /* A count of rows changed */ int regOldRowid; /* The old rowid */ int regNewRowid; /* The new rowid */ int regNew; /* 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); #if defined(SQLITE_ENABLE_SELINUX) if(0!=sqlite3StrNICmp(pTab->zName, "sqlite_", 7) && 0!=sqlite3StrNICmp(pTab->zName, "selinux_", 8)) { /* MODIFIED */ Expr *pNewWhere = NULL; char *f_name = sqlite3MPrintf(db, "%s", "selinux_check_access"); char *f_column = sqlite3MPrintf(db, "%s", "security_context"); char *f_class = sqlite3MPrintf(db, "%s", "db_tuple"); char *f_action = sqlite3MPrintf(db, "%s", "update"); for(i = 0; i < pTabList->nAlloc; i++){ Expr *pFName = sqlite3DbMallocZero(db, sizeof(Expr) + strlen(f_name) + 1); Expr *pFTable = sqlite3DbMallocZero(db, sizeof(Expr) + strlen(pTabList->a[i].zName) + 1); Expr *pFColumn = sqlite3DbMallocZero(db, sizeof(Expr) + strlen(f_column) + 1); Expr *pFClass = sqlite3DbMallocZero(db, sizeof(Expr) + strlen(f_class) + 1); Expr *pFAction = sqlite3DbMallocZero(db, sizeof(Expr) + strlen(f_action) + 1); Expr *pFDebug = sqlite3DbMallocZero(db, sizeof(Expr) + strlen(pTabList->a[i].zName) + 1); Expr *pFunction = sqlite3DbMallocZero(db, sizeof(Expr)); pFName->op = (u8)153; pFName->iAgg = -1; pFTable->op = (u8)27; pFTable->iAgg = -1; pFColumn->op = (u8)27; pFColumn->iAgg = -1; pFClass->op = (u8)97; pFClass->iAgg = -1; pFAction->op = (u8)97; pFAction->iAgg = -1; pFDebug->op = (u8)97; pFDebug->iAgg = -1; pFunction->op = (u8)122; pFunction->iAgg = -1; pFName->u.zToken = (char*)&pFName[1]; pFTable->u.zToken = (char*)&pFTable[1]; pFColumn->u.zToken = (char*)&pFColumn[1]; pFClass->u.zToken = (char*)&pFClass[1]; pFAction->u.zToken = (char*)&pFAction[1]; pFDebug->u.zToken = (char*)&pFDebug[1]; memcpy(pFName->u.zToken, f_name, strlen(f_name)); memcpy(pFTable->u.zToken, pTabList->a[i].zName, strlen(pTabList->a[i].zName)); memcpy(pFColumn->u.zToken, f_column, strlen(f_column)); memcpy(pFClass->u.zToken, f_class, strlen(f_class)); memcpy(pFAction->u.zToken, f_action, strlen(f_action)); memcpy(pFDebug->u.zToken, pTabList->a[i].zName, strlen(pTabList->a[i].zName)); pFName->u.zToken[strlen(f_name)] = 0; pFTable->u.zToken[strlen(pTabList->a[i].zName)] = 0; pFColumn->u.zToken[strlen(f_column)] = 0; pFClass->u.zToken[strlen(f_class)] = 0; pFAction->u.zToken[strlen(f_action)] = 0; pFDebug->u.zToken[strlen(pTabList->a[i].zName)] = 0; pFName->nHeight = 1; pFTable->nHeight = 1; pFColumn->nHeight = 1; pFClass->nHeight = 1; pFAction->nHeight = 1; pFDebug->nHeight = 1; sqlite3ExprAttachSubtrees(db, pFunction, pFTable, pFColumn); ExprList *pExprFunction; pExprFunction = sqlite3ExprListAppend(pParse, 0, pFunction); pExprFunction = sqlite3ExprListAppend(pParse, pExprFunction, pFClass); pExprFunction = sqlite3ExprListAppend(pParse, pExprFunction, pFAction); pExprFunction = sqlite3ExprListAppend(pParse, pExprFunction, pFDebug); pFName->x.pList = pExprFunction; sqlite3ExprSetHeight(pParse, pFName); if(pNewWhere) pNewWhere = sqlite3ExprAnd(db, pFName, pNewWhere); else pNewWhere = pFName; } if(pWhere) pWhere = sqlite3ExprAnd(db, pNewWhere, pWhere); else pWhere = pNewWhere; } /* ------------------------------------------------------------ */ #endif /* defined(SQLITE_ENABLE_SELINUX) */ /* Figure out if we have any triggers and if the table being ** updated is a view. */ #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask); isView = pTab->pSelect!=0; assert( pTrigger || tmask==0 ); #else # define pTrigger 0 # define isView 0 # define tmask 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, tmask) ){ goto update_cleanup; } /* Allocate a cursors for the main database table and for all indices. ** The index cursors might not be used, but if they are used they ** need to occur right after the database cursor. So go ahead and ** allocate enough space, just in case. */ pTabList->a[0].iCursor = iBaseCur = iDataCur = pParse->nTab++; iIdxCur = iDataCur+1; pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab); for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ if( pIdx->autoIndex==2 && pPk!=0 ){ iDataCur = pParse->nTab; pTabList->a[0].iCursor = iDataCur; } pParse->nTab++; } /* Allocate space for aXRef[], aRegIdx[], and aToOpen[]. ** Initialize aXRef[] and aToOpen[] to their default values. */ aXRef = sqlite3DbMallocRaw(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 ); if( aXRef==0 ) goto update_cleanup; aRegIdx = aXRef+pTab->nCol; aToOpen = (u8*)(aRegIdx+nIdx); memset(aToOpen, 1, nIdx+1); aToOpen[nIdx+1] = 0; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; /* Initialize the name-context */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; /* Resolve the column names in all the expressions of the ** of the UPDATE statement. Also find the column index ** for each column to be updated in the pChanges array. For each ** column to be updated, make sure we have authorization to change ** that column. */ chngRowid = chngPk = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){ chngPk = 1; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){ j = -1; chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); pParse->checkSchema = 1; goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, j<0 ? "ROWID" : pTab->aCol[j].zName, db->aDb[iDb].zName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } assert( (chngRowid & chngPk)==0 ); assert( chngRowid==0 || chngRowid==1 ); assert( chngPk==0 || chngPk==1 ); chngKey = chngRowid + chngPk; /* The SET expressions are not actually used inside the WHERE loop. ** So reset the colUsed mask */ pTabList->a[0].colUsed = 0; hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey); /* There is one entry in the aRegIdx[] array for each index on the table ** being updated. Fill in aRegIdx[] with a register number that will hold ** the key for accessing each index. */ for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngKey || hasFK || pIdx->pPartIdxWhere || pIdx==pPk ){ reg = ++pParse->nMem; }else{ reg = 0; for(i=0; i<pIdx->nKeyCol; i++){ if( aXRef[pIdx->aiColumn[i]]>=0 ){ reg = ++pParse->nMem; break; } } } if( reg==0 ) aToOpen[j+1] = 0; aRegIdx[j] = reg; } /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, 1, iDb); #ifndef SQLITE_OMIT_VIRTUALTABLE /* Virtual tables must be handled separately */ if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere, onError); pWhere = 0; pTabList = 0; goto update_cleanup; } #endif /* Allocate required registers. */ 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 ** a ephemeral table. */ #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, iDataCur); } #endif /* Resolve the column names in all the expressions in the ** WHERE clause. */ if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } /* Begin the database scan */ if( HasRowid(pTab) ){ sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid); pWInfo = sqlite3WhereBegin( pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur ); if( pWInfo==0 ) goto update_cleanup; okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); /* Remember the rowid of every item to be updated. */ sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid); if( !okOnePass ){ sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } /* End the database scan loop. */ sqlite3WhereEnd(pWInfo); }else{ int iPk; /* First of nPk memory cells holding PRIMARY KEY value */ i16 nPk; /* Number of components of the PRIMARY KEY */ int addrOpen; /* Address of the OpenEphemeral instruction */ assert( pPk!=0 ); nPk = pPk->nKeyCol; iPk = pParse->nMem+1; pParse->nMem += nPk; regKey = ++pParse->nMem; iEph = pParse->nTab++; sqlite3VdbeAddOp2(v, OP_Null, 0, iPk); addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk); sqlite3VdbeSetP4KeyInfo(pParse, pPk); pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, iIdxCur); if( pWInfo==0 ) goto update_cleanup; okOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); for(i=0; i<nPk; i++){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pPk->aiColumn[i], iPk+i); } if( okOnePass ){ sqlite3VdbeChangeToNoop(v, addrOpen); nKey = nPk; regKey = iPk; }else{ sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey, sqlite3IndexAffinityStr(v, pPk), nPk); sqlite3VdbeAddOp2(v, OP_IdxInsert, iEph, regKey); } sqlite3WhereEnd(pWInfo); } /* Initialize the count of updated rows */ if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } labelBreak = sqlite3VdbeMakeLabel(v); if( !isView ){ /* ** Open every index that needs updating. Note that if any ** index could potentially invoke a REPLACE conflict resolution ** action, then we need to open all indices because we might need ** to be deleting some records. */ if( onError==OE_Replace ){ memset(aToOpen, 1, nIdx+1); }else{ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->onError==OE_Replace ){ memset(aToOpen, 1, nIdx+1); break; } } } if( okOnePass ){ if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0; if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0; } sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, iBaseCur, aToOpen, 0, 0); } /* Top of the update loop */ if( okOnePass ){ if( aToOpen[iDataCur-iBaseCur] ){ assert( pPk!=0 ); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey, nKey); VdbeCoverageNeverTaken(v); } labelContinue = labelBreak; sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak); VdbeCoverage(v); }else if( pPk ){ labelContinue = sqlite3VdbeMakeLabel(v); sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v); addrTop = sqlite3VdbeAddOp2(v, OP_RowKey, iEph, regKey); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0); VdbeCoverage(v); }else{ labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet, labelBreak, regOldRowid); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } /* If the record number will change, set register regNewRowid to ** contain the new value. If the record number is not being modified, ** then regNewRowid is the same register as regOldRowid, which is ** already populated. */ assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid ); if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v); } /* Compute the old pre-UPDATE content of the row being changed, if that ** information is needed */ if( chngPk || hasFK || pTrigger ){ u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0); oldmask |= sqlite3TriggerColmask(pParse, pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( oldmask==0xffffffff || (i<32 && (oldmask & MASKBIT32(i))!=0) || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){ testcase( oldmask!=0xffffffff && i==31 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i); } } if( chngRowid==0 && pPk==0 ){ sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid); } } /* Populate the array of registers beginning at regNew with the new ** row data. This array is used to check 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 ); /*sqlite3VdbeAddOp3(v, OP_Null, 0, regNew, regNew+pTab->nCol-1);*/ 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); } /* If it did not delete it, the row-trigger may still have modified ** some of the columns of the row being updated. Load the values for ** all columns not modified by the update statement into their ** registers in case this has happened. */ for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 && i!=pTab->iPKey ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i); } } } if( !isView ){ int j1 = 0; /* Address of jump instruction */ int bReplace = 0; /* True if REPLACE conflict resolution might happen */ /* Do constraint checks. */ assert( regOldRowid>0 ); sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur, regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace); /* Do FK constraint checks. */ if( hasFK ){ sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey); } /* Delete the index entries associated with the current record. */ if( bReplace || chngKey ){ if( pPk ){ j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey); }else{ j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid); } VdbeCoverageNeverTaken(v); } sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx); /* If changing the record number, delete the old record. */ if( hasFK || chngKey || pPk!=0 ){ sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0); } if( bReplace || chngKey ){ sqlite3VdbeJumpHere(v, j1); } if( hasFK ){ sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey); } /* Insert the new index entries and the new record. */ sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx, 1, 0, 0); /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to ** handle rows (possibly in other tables) that refer via a foreign key ** to the row just updated. */ if( hasFK ){ sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey); } } /* Increment the row counter */ if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue); /* Repeat the above with the next record to be updated, until ** all record selected by the WHERE clause have been updated. */ if( okOnePass ){ /* Nothing to do at end-of-loop for a single-pass */ }else if( pPk ){ sqlite3VdbeResolveLabel(v, labelContinue); sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v); }else{ sqlite3VdbeAddOp2(v, OP_Goto, 0, labelContinue); } sqlite3VdbeResolveLabel(v, labelBreak); /* Close all tables */ for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){ assert( aRegIdx ); if( aToOpen[i+1] ){ sqlite3VdbeAddOp2(v, OP_Close, iIdxCur+i, 0); } } if( iDataCur<iIdxCur ) sqlite3VdbeAddOp2(v, OP_Close, iDataCur, 0); /* Update the sqlite_sequence table by storing the content of the ** maximum rowid counter values recorded while inserting into ** autoincrement tables. */ if( pParse->nested==0 && pParse->pTriggerTab==0 ){ sqlite3AutoincrementEnd(pParse); } /* ** Return the number of rows that were changed. If this routine is ** generating code because of a call to sqlite3NestedParse(), do not ** invoke the callback function. */ if( (db->flags&SQLITE_CountRows) && !pParse->pTriggerTab && !pParse->nested ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */ sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); return; }