engine/sqlite/src/update.cpp
changeset 71 fbd95db6a4e1
parent 69 4a65cc85c4f3
child 72 2e267e7da513
--- a/engine/sqlite/src/update.cpp	Wed Apr 28 13:20:05 2010 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,639 +0,0 @@
-/*
-** 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.
-**
-** $Id: update.cpp 1282 2008-11-13 09:31:33Z LarsPson $
-*/
-#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 */
-);
-#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 P3 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 P3 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 P3 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 P3 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.
-*/
-void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i){
-  if( pTab && !pTab->pSelect ){
-    sqlite3_value *pValue;
-    u8 enc = ENC(sqlite3VdbeDb(v));
-    Column *pCol = &pTab->aCol[i];
-    assert( i<pTab->nCol );
-    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, pCol->affinity, &pValue);
-    if( pValue ){
-      sqlite3VdbeChangeP3(v, -1, (const char *)pValue, P3_MEM);
-    }else{
-      VdbeComment((v, "# %s.%s", pTab->zName, pCol->zName));
-    }
-  }
-}
-
-/*
-** 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 nIdxTotal;         /* Total number of indices */
-  int iCur;              /* VDBE Cursor number of pTab */
-  sqlite3 *db;           /* The database structure */
-  Index **apIdx = 0;     /* An array of indices that need updating too */
-  char *aIdxUsed = 0;    /* aIdxUsed[i]==1 if the i-th index is used */
-  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 memCnt = 0;        /* Memory cell used for counting rows changed */
-  int mem1;      /* Memory address storing the rowid for next row to update */
-
-#ifndef SQLITE_OMIT_TRIGGER
-  int isView;                  /* Trying to update a view */
-  int triggers_exist = 0;      /* True if any row triggers exist */
-#endif
-
-  int newIdx      = -1;  /* index of trigger "new" temp table       */
-  int oldIdx      = -1;  /* index of trigger "old" temp table       */
-
-  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(pParse, 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 = (int*)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( sqlite3ExprResolveNames(&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 apIdx[] and fill it with pointers to every
-  ** index that needs to be updated.  Indices only need updating if their
-  ** key includes one of the columns named in pChanges or if the record
-  ** number of the original table entry is changing.
-  */
-  for(nIdx=nIdxTotal=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdxTotal++){
-    if( chngRowid ){
-      i = 0;
-    }else {
-      for(i=0; i<pIdx->nColumn; i++){
-        if( aXRef[pIdx->aiColumn[i]]>=0 ) break;
-      }
-    }
-    if( i<pIdx->nColumn ) nIdx++;
-  }
-  if( nIdxTotal>0 ){
-    apIdx = (Index**)sqlite3DbMallocRaw(db, sizeof(Index*) * nIdx + nIdxTotal );
-    if( apIdx==0 ) goto update_cleanup;
-    aIdxUsed = (char*)&apIdx[nIdx];
-  }
-  for(nIdx=j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
-    if( chngRowid ){
-      i = 0;
-    }else{
-      for(i=0; i<pIdx->nColumn; i++){
-        if( aXRef[pIdx->aiColumn[i]]>=0 ) break;
-      }
-    }
-    if( i<pIdx->nColumn ){
-      apIdx[nIdx++] = pIdx;
-      aIdxUsed[j] = 1;
-    }else{
-      aIdxUsed[j] = 0;
-    }
-  }
-
-  /* Begin generating code.
-  */
-  v = sqlite3GetVdbe(pParse);
-  if( v==0 ) goto update_cleanup;
-  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
-  sqlite3BeginWriteOperation(pParse, 1, iDb);
-  mem1 = pParse->nMem++;
-
-#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
-
-  /* Resolve the column names in all the expressions in the
-  ** WHERE clause.
-  */
-  if( sqlite3ExprResolveNames(&sNC, pWhere) ){
-    goto update_cleanup;
-  }
-
-  /* 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( isView ){
-    Select *pView;
-    pView = sqlite3SelectDup(db, pTab->pSelect);
-    sqlite3Select(pParse, pView, SRT_EphemTab, iCur, 0, 0, 0, 0);
-    sqlite3SelectDelete(pView);
-  }
-
-  /* Begin the database scan
-  */
-  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
-  if( pWInfo==0 ) goto update_cleanup;
-
-  /* Remember the rowid of every item to be updated.
-  */
-  sqlite3VdbeAddOp(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, 0);
-  sqlite3VdbeAddOp(v, OP_FifoWrite, 0, 0);
-
-  /* End the database scan loop.
-  */
-  sqlite3WhereEnd(pWInfo);
-
-  /* Initialize the count of updated rows
-  */
-  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
-    memCnt = pParse->nMem++;
-    sqlite3VdbeAddOp(v, OP_MemInt, 0, memCnt);
-  }
-
-  if( triggers_exist ){
-    
-    /* Create pseudo-tables for NEW and OLD
-    */
-    sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
-    sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
-    sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
-    sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
-
-    /* The top of the update loop for when there are triggers.
-    */
-    addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
-    sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
-    sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
-    
-    if( !isView ){
-      /* Open a cursor and make it point to the record that is
-      ** being updated.
-      */
-      sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
-    }
-    sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
-
-    /* Generate the OLD table
-    */
-    sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
-    sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
-    sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);
-
-    /* Generate the NEW table
-    */
-    if( chngRowid ){
-      sqlite3ExprCodeAndCache(pParse, pRowidExpr);
-    }else{
-      sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
-    }
-    for(i=0; i<pTab->nCol; i++){
-      if( i==pTab->iPKey ){
-        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
-        continue;
-      }
-      j = aXRef[i];
-      if( j<0 ){
-        sqlite3VdbeAddOp(v, OP_Column, iCur, i);
-        sqlite3ColumnDefault(v, pTab, i);
-      }else{
-        sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
-      }
-    }
-    sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
-    if( !isView ){
-      sqlite3TableAffinityStr(v, pTab);
-    }
-    if( pParse->nErr ) goto update_cleanup;
-    sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0);
-    if( !isView ){
-      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
-    }
-
-    /* Fire the BEFORE and INSTEAD OF triggers
-    */
-    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
-          newIdx, oldIdx, onError, addr) ){
-      goto update_cleanup;
-    }
-    
-    if( !isView ){
-      sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
-    }
-  }
-
-  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.
-    */
-    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 || aIdxUsed[i] ){
-        KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
-        sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
-        sqlite3VdbeOp3(v, OP_OpenWrite, iCur+i+1, pIdx->tnum,
-                       (char*)pKey, P3_KEYINFO_HANDOFF);
-        assert( pParse->nTab>iCur+i+1 );
-      }
-    }
-
-    /* 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.
-    */
-    if( !triggers_exist ){
-      addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
-      sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
-      sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
-    }
-    sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
-    sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
-
-    /* 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);
-      sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
-    }
-
-    /* Compute new data for this record.  
-    */
-    for(i=0; i<pTab->nCol; i++){
-      if( i==pTab->iPKey ){
-        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
-        continue;
-      }
-      j = aXRef[i];
-      if( j<0 ){
-        sqlite3VdbeAddOp(v, OP_Column, iCur, i);
-        sqlite3ColumnDefault(v, pTab, i);
-      }else{
-        sqlite3ExprCode(pParse, pChanges->a[j].pExpr);
-      }
-    }
-
-    /* Do constraint checks
-    */
-    sqlite3GenerateConstraintChecks(pParse, pTab, iCur, aIdxUsed, chngRowid, 1,
-                                   onError, addr);
-
-    /* Delete the old indices for the current record.
-    */
-    sqlite3GenerateRowIndexDelete(v, pTab, iCur, aIdxUsed);
-
-    /* If changing the record number, delete the old record.
-    */
-    if( chngRowid ){
-      sqlite3VdbeAddOp(v, OP_Delete, iCur, 0);
-    }
-
-    /* Create the new index entries and the new record.
-    */
-    sqlite3CompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRowid, 1, -1, 0);
-  }
-
-  /* Increment the row counter 
-  */
-  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
-    sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt);
-  }
-
-  /* If there are triggers, close all the cursors after each iteration
-  ** through the loop.  The fire the after triggers.
-  */
-  if( triggers_exist ){
-    if( !isView ){
-      for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
-        if( openAll || aIdxUsed[i] )
-          sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
-      }
-      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
-    }
-    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 
-          newIdx, oldIdx, onError, addr) ){
-      goto update_cleanup;
-    }
-  }
-
-  /* Repeat the above with the next record to be updated, until
-  ** all record selected by the WHERE clause have been updated.
-  */
-  sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
-  sqlite3VdbeJumpHere(v, addr);
-
-  /* Close all tables if there were no FOR EACH ROW triggers */
-  if( !triggers_exist ){
-    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
-      if( openAll || aIdxUsed[i] ){
-        sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
-      }
-    }
-    sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
-  }else{
-    sqlite3VdbeAddOp(v, OP_Close, newIdx, 0);
-    sqlite3VdbeAddOp(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 ){
-    sqlite3VdbeAddOp(v, OP_MemLoad, memCnt, 0);
-    sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
-    sqlite3VdbeSetNumCols(v, 1);
-    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", P3_STATIC);
-  }
-
-update_cleanup:
-  sqlite3AuthContextPop(&sContext);
-  sqlite3_free(apIdx);
-  sqlite3_free(aXRef);
-  sqlite3SrcListDelete(pTabList);
-  sqlite3ExprListDelete(pChanges);
-  sqlite3ExprDelete(pWhere);
-  return;
-}
-
-#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 */
-){
-  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 */
-  sqlite3 *db = pParse->db; /* Database connection */
-
-  /* Construct the SELECT statement that will find the new values for
-  ** all updated rows. 
-  */
-  pEList = sqlite3ExprListAppend(pParse, 0, 
-                                 sqlite3CreateIdExpr(pParse, "_rowid_"), 0);
-  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);
-    }else{
-      pExpr = sqlite3CreateIdExpr(pParse, pTab->aCol[i].zName);
-    }
-    pEList = sqlite3ExprListAppend(pParse, pEList, pExpr, 0);
-  }
-  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++;
-  sqlite3VdbeAddOp(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));
-
-  /* fill the ephemeral table 
-  */
-  sqlite3Select(pParse, pSelect, SRT_Table, ephemTab, 0, 0, 0, 0);
-
-  /*
-  ** Generate code to scan the ephemeral table and call VDelete and
-  ** VInsert
-  */
-  sqlite3VdbeAddOp(v, OP_Rewind, ephemTab, 0);
-  addr = sqlite3VdbeCurrentAddr(v);
-  sqlite3VdbeAddOp(v, OP_Column,  ephemTab, 0);
-  if( pRowid ){
-    sqlite3VdbeAddOp(v, OP_Column, ephemTab, 1);
-  }else{
-    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
-  }
-  for(i=0; i<pTab->nCol; i++){
-    sqlite3VdbeAddOp(v, OP_Column, ephemTab, i+1+(pRowid!=0));
-  }
-  pParse->pVirtualLock = pTab;
-  sqlite3VdbeOp3(v, OP_VUpdate, 0, pTab->nCol+2, 
-                     (const char*)pTab->pVtab, P3_VTAB);
-  sqlite3VdbeAddOp(v, OP_Next, ephemTab, addr);
-  sqlite3VdbeJumpHere(v, addr-1);
-  sqlite3VdbeAddOp(v, OP_Close, ephemTab, 0);
-
-  /* Cleanup */
-  sqlite3SelectDelete(pSelect);  
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */