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Diffstat (limited to 'src/update.c')
-rw-r--r-- | src/update.c | 672 |
1 files changed, 672 insertions, 0 deletions
diff --git a/src/update.c b/src/update.c new file mode 100644 index 0000000..1e30522 --- /dev/null +++ b/src/update.c @@ -0,0 +1,672 @@ +/* +** 2001 September 15 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +************************************************************************* +** This file contains C code routines that are called by the parser +** to handle UPDATE statements. +*/ +#include "sqliteInt.h" + +#ifndef SQLITE_OMIT_VIRTUALTABLE +/* Forward declaration */ +static void updateVirtualTable( + Parse *pParse, /* The parsing context */ + SrcList *pSrc, /* The virtual table to be modified */ + Table *pTab, /* The virtual table */ + ExprList *pChanges, /* The columns to change in the UPDATE statement */ + Expr *pRowidExpr, /* Expression used to recompute the rowid */ + int *aXRef, /* Mapping from columns of pTab to entries in pChanges */ + Expr *pWhere, /* WHERE clause of the UPDATE statement */ + int onError /* ON CONFLICT strategy */ +); +#endif /* SQLITE_OMIT_VIRTUALTABLE */ + +/* +** The most recently coded instruction was an OP_Column to retrieve the +** i-th column of table pTab. This routine sets the P4 parameter of the +** OP_Column to the default value, if any. +** +** The default value of a column is specified by a DEFAULT clause in the +** column definition. This was either supplied by the user when the table +** was created, or added later to the table definition by an ALTER TABLE +** command. If the latter, then the row-records in the table btree on disk +** may not contain a value for the column and the default value, taken +** from the P4 parameter of the OP_Column instruction, is returned instead. +** If the former, then all row-records are guaranteed to include a value +** for the column and the P4 value is not required. +** +** Column definitions created by an ALTER TABLE command may only have +** literal default values specified: a number, null or a string. (If a more +** complicated default expression value was provided, it is evaluated +** when the ALTER TABLE is executed and one of the literal values written +** into the sqlite_master table.) +** +** Therefore, the P4 parameter is only required if the default value for +** the column is a literal number, string or null. The sqlite3ValueFromExpr() +** function is capable of transforming these types of expressions into +** sqlite3_value objects. +** +** If parameter iReg is not negative, code an OP_RealAffinity instruction +** on register iReg. This is used when an equivalent integer value is +** stored in place of an 8-byte floating point value in order to save +** space. +*/ +void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i, int iReg){ + assert( pTab!=0 ); + if( !pTab->pSelect ){ + sqlite3_value *pValue; + u8 enc = ENC(sqlite3VdbeDb(v)); + Column *pCol = &pTab->aCol[i]; + VdbeComment((v, "%s.%s", pTab->zName, pCol->zName)); + assert( i<pTab->nCol ); + sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, + pCol->affinity, &pValue); + if( pValue ){ + sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM); + } +#ifndef SQLITE_OMIT_FLOATING_POINT + if( iReg>=0 && pTab->aCol[i].affinity==SQLITE_AFF_REAL ){ + sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg); + } +#endif + } +} + +/* +** 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 */ + + 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( hasFK || 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, onError); + 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; + + /* 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, 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++){ + assert( aRegIdx ); + 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 || (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); + } + } + + /* 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++){ + assert( aRegIdx ); + 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; +} +/* Make sure "isView" and other macros defined above are undefined. Otherwise +** thely may interfere with compilation of other functions in this file +** (or in another file, if this file becomes part of the amalgamation). */ +#ifdef isView + #undef isView +#endif +#ifdef pTrigger + #undef pTrigger +#endif + +#ifndef SQLITE_OMIT_VIRTUALTABLE +/* +** Generate code for an UPDATE of a virtual table. +** +** The strategy is that we create an ephemerial table that contains +** for each row to be changed: +** +** (A) The original rowid of that row. +** (B) The revised rowid for the row. (note1) +** (C) The content of every column in the row. +** +** Then we loop over this ephemeral table and for each row in +** the ephermeral table call VUpdate. +** +** When finished, drop the ephemeral table. +** +** (note1) Actually, if we know in advance that (A) is always the same +** as (B) we only store (A), then duplicate (A) when pulling +** it out of the ephemeral table before calling VUpdate. +*/ +static void updateVirtualTable( + Parse *pParse, /* The parsing context */ + SrcList *pSrc, /* The virtual table to be modified */ + Table *pTab, /* The virtual table */ + ExprList *pChanges, /* The columns to change in the UPDATE statement */ + Expr *pRowid, /* Expression used to recompute the rowid */ + int *aXRef, /* Mapping from columns of pTab to entries in pChanges */ + Expr *pWhere, /* WHERE clause of the UPDATE statement */ + int onError /* ON CONFLICT strategy */ +){ + Vdbe *v = pParse->pVdbe; /* Virtual machine under construction */ + ExprList *pEList = 0; /* The result set of the SELECT statement */ + Select *pSelect = 0; /* The SELECT statement */ + Expr *pExpr; /* Temporary expression */ + int ephemTab; /* Table holding the result of the SELECT */ + int i; /* Loop counter */ + int addr; /* Address of top of loop */ + int iReg; /* First register in set passed to OP_VUpdate */ + sqlite3 *db = pParse->db; /* Database connection */ + const char *pVTab = (const char*)sqlite3GetVTable(db, pTab); + SelectDest dest; + + /* Construct the SELECT statement that will find the new values for + ** all updated rows. + */ + pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db, TK_ID, "_rowid_")); + if( pRowid ){ + pEList = sqlite3ExprListAppend(pParse, pEList, + sqlite3ExprDup(db, pRowid, 0)); + } + assert( pTab->iPKey<0 ); + for(i=0; i<pTab->nCol; i++){ + if( aXRef[i]>=0 ){ + pExpr = sqlite3ExprDup(db, pChanges->a[aXRef[i]].pExpr, 0); + }else{ + pExpr = sqlite3Expr(db, TK_ID, pTab->aCol[i].zName); + } + pEList = sqlite3ExprListAppend(pParse, pEList, pExpr); + } + pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0); + + /* Create the ephemeral table into which the update results will + ** be stored. + */ + assert( v ); + ephemTab = pParse->nTab++; + sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0)); + sqlite3VdbeChangeP5(v, BTREE_UNORDERED); + + /* fill the ephemeral table + */ + sqlite3SelectDestInit(&dest, SRT_Table, ephemTab); + sqlite3Select(pParse, pSelect, &dest); + + /* Generate code to scan the ephemeral table and call VUpdate. */ + iReg = ++pParse->nMem; + pParse->nMem += pTab->nCol+1; + addr = sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0); + sqlite3VdbeAddOp3(v, OP_Column, ephemTab, 0, iReg); + sqlite3VdbeAddOp3(v, OP_Column, ephemTab, (pRowid?1:0), iReg+1); + for(i=0; i<pTab->nCol; i++){ + sqlite3VdbeAddOp3(v, OP_Column, ephemTab, i+1+(pRowid!=0), iReg+2+i); + } + sqlite3VtabMakeWritable(pParse, pTab); + sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, iReg, pVTab, P4_VTAB); + sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError); + sqlite3MayAbort(pParse); + sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr+1); + sqlite3VdbeJumpHere(v, addr); + sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0); + + /* Cleanup */ + sqlite3SelectDelete(db, pSelect); +} +#endif /* SQLITE_OMIT_VIRTUALTABLE */ |