}
  iCol = pExpr->iColumn;
  if( NEVER(pTab==0) ) return;

  if( iCol>=0 ){
    assert( iCol<pTab->nCol );
    zCol = pTab->aCol[iCol].zName;
  }else if( pTab->iPKey>=0 ){
    assert( pTab->iPKey<pTab->nCol );
    zCol = pTab->aCol[pTab->iPKey].zName;
  }else{
    zCol = "ROWID";
  }
  assert( iDb>=0 && iDb<db->nDb );
  if( SQLITE_IGNORE==sqlite4AuthReadCol(pParse, pTab->zName, zCol, iDb) ){
    pExpr->op = TK_NULL;
  }

  }
  iCol = pExpr->iColumn;
  if( NEVER(pTab==0) ) return;

  if( iCol>=0 ){
    assert( iCol<pTab->nCol );
    zCol = pTab->aCol[iCol].zName;



  }else{
    zCol = "ROWID";
  }
  assert( iDb>=0 && iDb<db->nDb );
  if( SQLITE_IGNORE==sqlite4AuthReadCol(pParse, pTab->zName, zCol, iDb) ){
    pExpr->op = TK_NULL;
  }

  if( pTable==0 ){
    db->mallocFailed = 1;
    pParse->rc = SQLITE_NOMEM;
    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;
  pTable->iPKey = -1;
  pTable->pSchema = db->aDb[iDb].pSchema;
  pTable->nRef = 1;
  pTable->nRowEst = 1000000;
  assert( pParse->pNewTable==0 );
  pParse->pNewTable = pTable;

  /* If this is the magic sqlite_sequence table used by autoincrement,

  if( pTable==0 ){
    db->mallocFailed = 1;
    pParse->rc = SQLITE_NOMEM;
    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;

  pTable->pSchema = db->aDb[iDb].pSchema;
  pTable->nRef = 1;
  pTable->nRowEst = 1000000;
  assert( pParse->pNewTable==0 );
  pParse->pNewTable = pTable;

  /* If this is the magic sqlite_sequence table used by autoincrement,

  int nCol;

  nCol = pIdx->nColumn;
  regBase = sqlite4GetTempRange(pParse, nCol+1);
  sqlite4VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
  for(j=0; j<nCol; j++){
    int idx = pIdx->aiColumn[j];
    if( idx==pTab->iPKey ){
      sqlite4VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
    }else{
      sqlite4VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
      sqlite4ColumnDefault(v, pTab, idx, -1);
    }
  }
  if( doMakeRec ){

  int nCol;

  nCol = pIdx->nColumn;
  regBase = sqlite4GetTempRange(pParse, nCol+1);
  sqlite4VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
  for(j=0; j<nCol; j++){
    int idx = pIdx->aiColumn[j];
    if( idx<0 ){
      sqlite4VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j);
    }else{
      sqlite4VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
      sqlite4ColumnDefault(v, pTab, idx, -1);
    }
  }
  if( doMakeRec ){

void sqlite4ExprCodeGetColumnOfTable(
  Vdbe *v,        /* The VDBE under construction */
  Table *pTab,    /* The table containing the value */
  int iTabCur,    /* The cursor for this table */
  int iCol,       /* Index of the column to extract */
  int regOut      /* Extract the valud into this register */
){
  if( iCol<0 || iCol==pTab->iPKey ){
    sqlite4VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite4VdbeAddOp3(v, op, iTabCur, iCol, regOut);
  }
  if( iCol>=0 ){
    sqlite4ColumnDefault(v, pTab, iCol, regOut);
................................................................................
      **   p1==2   ->    old.b         p1==5   ->    new.b       
      */
      Table *pTab = pExpr->pTab;
      int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;

      assert( pExpr->iTable==0 || pExpr->iTable==1 );
      assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );
      assert( pTab->iPKey<0 || pExpr->iColumn!=pTab->iPKey );
      assert( p1>=0 && p1<(pTab->nCol*2+2) );

      sqlite4VdbeAddOp2(v, OP_Param, p1, target);
      VdbeComment((v, "%s.%s -> $%d",
        (pExpr->iTable ? "new" : "old"),
        (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
        target

void sqlite4ExprCodeGetColumnOfTable(
  Vdbe *v,        /* The VDBE under construction */
  Table *pTab,    /* The table containing the value */
  int iTabCur,    /* The cursor for this table */
  int iCol,       /* Index of the column to extract */
  int regOut      /* Extract the valud into this register */
){
  if( iCol<0 ){
    sqlite4VdbeAddOp2(v, OP_Rowid, iTabCur, regOut);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite4VdbeAddOp3(v, op, iTabCur, iCol, regOut);
  }
  if( iCol>=0 ){
    sqlite4ColumnDefault(v, pTab, iCol, regOut);
................................................................................
      **   p1==2   ->    old.b         p1==5   ->    new.b       
      */
      Table *pTab = pExpr->pTab;
      int p1 = pExpr->iTable * (pTab->nCol+1) + 1 + pExpr->iColumn;

      assert( pExpr->iTable==0 || pExpr->iTable==1 );
      assert( pExpr->iColumn>=-1 && pExpr->iColumn<pTab->nCol );

      assert( p1>=0 && p1<(pTab->nCol*2+2) );

      sqlite4VdbeAddOp2(v, OP_Param, p1, target);
      VdbeComment((v, "%s.%s -> $%d",
        (pExpr->iTable ? "new" : "old"),
        (pExpr->iColumn<0 ? "rowid" : pExpr->pTab->aCol[pExpr->iColumn].zName),
        target

*/
static int kvmemKeyCompare(
  const KVByteArray *aK1, KVSize nK1,
  const KVByteArray *aK2, KVSize nK2
){
  int c;
  c = memcmp(aK1, aK2, nK1<nK2 ? nK1 : nK2);
  if( c==0 ) c = nK2 - nK1;
  return c;
}

/*
** Create a new KVMemData object
*/
static KVMemData *kvmemDataNew(const KVByteArray *aData, KVSize nData){

*/
static int kvmemKeyCompare(
  const KVByteArray *aK1, KVSize nK1,
  const KVByteArray *aK2, KVSize nK2
){
  int c;
  c = memcmp(aK1, aK2, nK1<nK2 ? nK1 : nK2);
  if( c==0 ) c = nK1 - nK2;
  return c;
}

/*
** Create a new KVMemData object
*/
static KVMemData *kvmemDataNew(const KVByteArray *aData, KVSize nData){

              if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
            }
            cnt++;
            pExpr->iTable = pItem->iCursor;
            pExpr->pTab = pTab;
            pMatch = pItem;
            pSchema = pTab->pSchema;
            /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
            pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
            break;
          }
        }
      }
    }

#ifndef SQLITE_OMIT_TRIGGER
................................................................................
      if( pTab ){ 
        int iCol;
        pSchema = pTab->pSchema;
        cntTab++;
        for(iCol=0; iCol<pTab->nCol; iCol++){
          Column *pCol = &pTab->aCol[iCol];
          if( sqlite4StrICmp(pCol->zName, zCol)==0 ){
            if( iCol==pTab->iPKey ){
              iCol = -1;
            }
            break;
          }
        }
        if( iCol>=pTab->nCol && sqlite4IsRowid(zCol) ){
          iCol = -1;        /* IMP: R-44911-55124 */
        }
        if( iCol<pTab->nCol ){
................................................................................
*/
Expr *sqlite4CreateColumnExpr(sqlite4 *db, SrcList *pSrc, int iSrc, int iCol){
  Expr *p = sqlite4ExprAlloc(db, TK_COLUMN, 0, 0);
  if( p ){
    struct SrcList_item *pItem = &pSrc->a[iSrc];
    p->pTab = pItem->pTab;
    p->iTable = pItem->iCursor;
    if( p->pTab->iPKey==iCol ){
      p->iColumn = -1;
    }else{
      p->iColumn = (ynVar)iCol;
      testcase( iCol==BMS );
      testcase( iCol==BMS-1 );
      pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);
    }
    ExprSetProperty(p, EP_Resolved);
  }
  return p;
}

/*
** This routine is callback for sqlite4WalkExpr().

              if( nameInUsingClause(pItem->pUsing, zCol) ) continue;
            }
            cnt++;
            pExpr->iTable = pItem->iCursor;
            pExpr->pTab = pTab;
            pMatch = pItem;
            pSchema = pTab->pSchema;

            pExpr->iColumn = (i16)j;
            break;
          }
        }
      }
    }

#ifndef SQLITE_OMIT_TRIGGER
................................................................................
      if( pTab ){ 
        int iCol;
        pSchema = pTab->pSchema;
        cntTab++;
        for(iCol=0; iCol<pTab->nCol; iCol++){
          Column *pCol = &pTab->aCol[iCol];
          if( sqlite4StrICmp(pCol->zName, zCol)==0 ){



            break;
          }
        }
        if( iCol>=pTab->nCol && sqlite4IsRowid(zCol) ){
          iCol = -1;        /* IMP: R-44911-55124 */
        }
        if( iCol<pTab->nCol ){
................................................................................
*/
Expr *sqlite4CreateColumnExpr(sqlite4 *db, SrcList *pSrc, int iSrc, int iCol){
  Expr *p = sqlite4ExprAlloc(db, TK_COLUMN, 0, 0);
  if( p ){
    struct SrcList_item *pItem = &pSrc->a[iSrc];
    p->pTab = pItem->pTab;
    p->iTable = pItem->iCursor;



    p->iColumn = (ynVar)iCol;
    testcase( iCol==BMS );
    testcase( iCol==BMS-1 );
    pItem->colUsed |= ((Bitmask)1)<<(iCol>=BMS ? BMS-1 : iCol);

    ExprSetProperty(p, EP_Resolved);
  }
  return p;
}

/*
** This routine is callback for sqlite4WalkExpr().

          sNC.pNext = pNC;
          sNC.pParse = pNC->pParse;
          zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
        }
      }else if( ALWAYS(pTab->pSchema) ){
        /* A real table */
        assert( !pS );
        if( iCol<0 ) iCol = pTab->iPKey;
        assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
        if( iCol<0 ){
          zType = "INTEGER";
          zOriginCol = "rowid";
        }else{
          zType = pTab->aCol[iCol].zType;
          zOriginCol = pTab->aCol[iCol].zName;
................................................................................
      char *zCol;
      int iCol = p->iColumn;
      for(j=0; ALWAYS(j<pTabList->nSrc); j++){
        if( pTabList->a[j].iCursor==p->iTable ) break;
      }
      assert( j<pTabList->nSrc );
      pTab = pTabList->a[j].pTab;
      if( iCol<0 ) iCol = pTab->iPKey;
      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
      if( iCol<0 ){
        zCol = "rowid";
      }else{
        zCol = pTab->aCol[iCol].zName;
      }
      sqlite4VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
................................................................................
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
      if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){
        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
        pTab = pColExpr->pTab;
        if( iCol<0 ) iCol = pTab->iPKey;
        zName = sqlite4MPrintf(db, "%s",
                 iCol>=0 ? pTab->aCol[iCol].zName : "rowid");
      }else if( pColExpr->op==TK_ID ){
        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
        zName = sqlite4MPrintf(db, "%s", pColExpr->u.zToken);
      }else{
        /* Use the original text of the column expression as its name */
................................................................................
  ** is disabled */
  assert( db->lookaside.bEnabled==0 );
  pTab->nRef = 1;
  pTab->zName = 0;
  pTab->nRowEst = 1000000;
  selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
  selectAddColumnTypeAndCollation(pParse, pTab->nCol, pTab->aCol, pSelect);
  pTab->iPKey = -1;
  if( db->mallocFailed ){
    sqlite4DeleteTable(db, pTab);
    return 0;
  }
  return pTab;
}

................................................................................
      sqlite4WalkSelect(pWalker, pSel);
      pFrom->pTab = pTab = sqlite4DbMallocZero(db, sizeof(Table));
      if( pTab==0 ) return WRC_Abort;
      pTab->nRef = 1;
      pTab->zName = sqlite4MPrintf(db, "sqlite_subquery_%p_", (void*)pTab);
      while( pSel->pPrior ){ pSel = pSel->pPrior; }
      selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol);
      pTab->iPKey = -1;
      pTab->nRowEst = 1000000;
      pTab->tabFlags |= TF_Ephemeral;
#endif
    }else{
      /* An ordinary table or view name in the FROM clause */
      assert( pFrom->pTab==0 );
      pFrom->pTab = pTab = 

          sNC.pNext = pNC;
          sNC.pParse = pNC->pParse;
          zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
        }
      }else if( ALWAYS(pTab->pSchema) ){
        /* A real table */
        assert( !pS );

        assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
        if( iCol<0 ){
          zType = "INTEGER";
          zOriginCol = "rowid";
        }else{
          zType = pTab->aCol[iCol].zType;
          zOriginCol = pTab->aCol[iCol].zName;
................................................................................
      char *zCol;
      int iCol = p->iColumn;
      for(j=0; ALWAYS(j<pTabList->nSrc); j++){
        if( pTabList->a[j].iCursor==p->iTable ) break;
      }
      assert( j<pTabList->nSrc );
      pTab = pTabList->a[j].pTab;

      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
      if( iCol<0 ){
        zCol = "rowid";
      }else{
        zCol = pTab->aCol[iCol].zName;
      }
      sqlite4VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
................................................................................
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
      if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){
        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
        pTab = pColExpr->pTab;

        zName = sqlite4MPrintf(db, "%s",
                 iCol>=0 ? pTab->aCol[iCol].zName : "rowid");
      }else if( pColExpr->op==TK_ID ){
        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
        zName = sqlite4MPrintf(db, "%s", pColExpr->u.zToken);
      }else{
        /* Use the original text of the column expression as its name */
................................................................................
  ** is disabled */
  assert( db->lookaside.bEnabled==0 );
  pTab->nRef = 1;
  pTab->zName = 0;
  pTab->nRowEst = 1000000;
  selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol);
  selectAddColumnTypeAndCollation(pParse, pTab->nCol, pTab->aCol, pSelect);

  if( db->mallocFailed ){
    sqlite4DeleteTable(db, pTab);
    return 0;
  }
  return pTab;
}

................................................................................
      sqlite4WalkSelect(pWalker, pSel);
      pFrom->pTab = pTab = sqlite4DbMallocZero(db, sizeof(Table));
      if( pTab==0 ) return WRC_Abort;
      pTab->nRef = 1;
      pTab->zName = sqlite4MPrintf(db, "sqlite_subquery_%p_", (void*)pTab);
      while( pSel->pPrior ){ pSel = pSel->pPrior; }
      selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol);

      pTab->nRowEst = 1000000;
      pTab->tabFlags |= TF_Ephemeral;
#endif
    }else{
      /* An ordinary table or view name in the FROM clause */
      assert( pFrom->pTab==0 );
      pFrom->pTab = pTab = 

** refers VDBE cursor number that holds the table open, not to the root
** page number.  Transient tables are used to hold the results of a
** sub-query that appears instead of a real table name in the FROM clause 
** of a SELECT statement.
*/
struct Table {
  char *zName;         /* Name of the table or view */
  int iPKey;           /* If not negative, use aCol[iPKey] as the primary key */
  int nCol;            /* Number of columns in this table */
  Column *aCol;        /* Information about each column */
  Index *pIndex;       /* List of SQL indexes on this table. */
#if 0
  int tnum;            /* Root BTree node for this table (see note above) */
#endif
  tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
  Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
  u16 nRef;            /* Number of pointers to this Table */
  u8 tabFlags;         /* Mask of TF_* values */
  u8 keyConf;          /* What to do in case of uniqueness conflict on iPKey */
  FKey *pFKey;         /* Linked list of all foreign keys in this table */
  char *zColAff;       /* String defining the affinity of each column */
#ifndef SQLITE_OMIT_CHECK
  Expr *pCheck;        /* The AND of all CHECK constraints */
#endif
#ifndef SQLITE_OMIT_ALTERTABLE
  int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */

** refers VDBE cursor number that holds the table open, not to the root
** page number.  Transient tables are used to hold the results of a
** sub-query that appears instead of a real table name in the FROM clause 
** of a SELECT statement.
*/
struct Table {
  char *zName;         /* Name of the table or view */

  int nCol;            /* Number of columns in this table */
  Column *aCol;        /* Information about each column */
  Index *pIndex;       /* List of SQL indexes on this table. */



  tRowcnt nRowEst;     /* Estimated rows in table - from sqlite_stat1 table */
  Select *pSelect;     /* NULL for tables.  Points to definition if a view. */
  u16 nRef;            /* Number of pointers to this Table */
  u8 tabFlags;         /* Mask of TF_* values */

  FKey *pFKey;         /* Linked list of all foreign keys in this table */
  char *zColAff;       /* String defining the affinity of each column */
#ifndef SQLITE_OMIT_CHECK
  Expr *pCheck;        /* The AND of all CHECK constraints */
#endif
#ifndef SQLITE_OMIT_ALTERTABLE
  int addColOffset;    /* Offset in CREATE TABLE stmt to add a new column */

  int regOld = 0;        /* Content of OLD.* table in triggers */

  int regKeySet = 0;              /* Register containing KeySet object */
  Index *pPk;                     /* The primary key index of this table */
  int iPk;                        /* Offset of primary key in aRegIdx[] */
  int bChngPk = 0;                /* True if any PK columns are updated */
  int bOpenAll = 0;               /* True if all indexes were opened */


  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
    goto update_cleanup;
  }
  assert( pSrc->nSrc==1 );

  /* Locate the table which we want to update. */
  pTab = sqlite4SrcListLookup(pParse, pSrc);
  if( pTab==0 ) goto update_cleanup;
  iDb = sqlite4SchemaToIndex(pParse->db, pTab->pSchema);
  pPk = sqlite4FindPrimaryKey(pTab, &iPk);


  /* Figure out if we have any triggers and if the table being
  ** updated is a view.
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite4TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
  isView = pTab->pSelect!=0;
................................................................................
  /* Allocate other required registers. */
  regKeySet = ++pParse->nMem;
  regOldKey = ++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 ){
    sqlite4AuthContextPush(pParse, &sContext, pTab->zName);
  }
................................................................................
       */
      testcase( i==31 );
      testcase( i==32 );
      sqlite4VdbeAddOp3(v, OP_Column, iCur+iPk, i, regNew+i);
      sqlite4ColumnDefault(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 ){
    sqlite4VdbeAddOp2(v, OP_Affinity, regNew, pTab->nCol);
    sqlite4TableAffinityStr(v, pTab);
................................................................................

    /* 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 ){
        sqlite4VdbeAddOp3(v, OP_Column, iCur, i, regNew+i);
        sqlite4ColumnDefault(v, pTab, i, regNew+i);
      }
    }
  }

  if( !isView ){
    int j1;                       /* Address of jump instruction */


    /* Do constraint checks. */
    assert( bChngPk==0 || pPk->aiColumn[0]>=0 );
    if( bChngPk==0 ) aRegIdx[iPk] = 0;
    sqlite4GenerateConstraintChecks(
        pParse, pTab, iCur, regNew, aRegIdx, 0, 1, onError, addr, 0
    );
    if( bChngPk==0 ) aRegIdx[iPk] = regOldKey;

    /* Do FK constraint checks. */

  int regOld = 0;        /* Content of OLD.* table in triggers */

  int regKeySet = 0;              /* Register containing KeySet object */
  Index *pPk;                     /* The primary key index of this table */
  int iPk;                        /* Offset of primary key in aRegIdx[] */
  int bChngPk = 0;                /* True if any PK columns are updated */
  int bOpenAll = 0;               /* True if all indexes were opened */
  int bImplicitPk;                /* True if pTab has an implicit PK */

  memset(&sContext, 0, sizeof(sContext));
  db = pParse->db;
  if( pParse->nErr || db->mallocFailed ){
    goto update_cleanup;
  }
  assert( pSrc->nSrc==1 );

  /* Locate the table which we want to update. */
  pTab = sqlite4SrcListLookup(pParse, pSrc);
  if( pTab==0 ) goto update_cleanup;
  iDb = sqlite4SchemaToIndex(pParse->db, pTab->pSchema);
  pPk = sqlite4FindPrimaryKey(pTab, &iPk);
  bImplicitPk = (pPk->aiColumn[0]<0);

  /* Figure out if we have any triggers and if the table being
  ** updated is a view.
  */
#ifndef SQLITE_OMIT_TRIGGER
  pTrigger = sqlite4TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask);
  isView = pTab->pSelect!=0;
................................................................................
  /* Allocate other required registers. */
  regKeySet = ++pParse->nMem;
  regOldKey = ++pParse->nMem;
  if( pTrigger || hasFK ){
    regOld = pParse->nMem + 1;
    pParse->nMem += pTab->nCol;
  }
#if 0
  if( chngRowid || pTrigger || hasFK ){
    regNewRowid = ++pParse->nMem;
  }
#endif
  if( bImplicitPk ) pParse->nMem++;
  regNew = pParse->nMem + 1;
  pParse->nMem += pTab->nCol;

  /* Start the view context. */
  if( isView ){
    sqlite4AuthContextPush(pParse, &sContext, pTab->zName);
  }
................................................................................
       */
      testcase( i==31 );
      testcase( i==32 );
      sqlite4VdbeAddOp3(v, OP_Column, iCur+iPk, i, regNew+i);
      sqlite4ColumnDefault(v, pTab, i, regNew+i);
    }
  }
  if( bImplicitPk ){
    sqlite4VdbeAddOp2(v, OP_Rowid, iCur+iPk, regNew-1);
  }

  /* Fire any BEFORE UPDATE triggers. This happens before constraints are
  ** verified. One could argue that this is wrong.
  */
  if( tmask&TRIGGER_BEFORE ){
    sqlite4VdbeAddOp2(v, OP_Affinity, regNew, pTab->nCol);
    sqlite4TableAffinityStr(v, pTab);
................................................................................

    /* 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 ){
        sqlite4VdbeAddOp3(v, OP_Column, iCur, i, regNew+i);
        sqlite4ColumnDefault(v, pTab, i, regNew+i);
      }
    }
  }

  if( !isView ){
    int j1;                       /* Address of jump instruction */


    /* Do constraint checks. */
    assert( bChngPk==0 || bImplicitPk==0 );
    if( bChngPk==0 ) aRegIdx[iPk] = 0;
    sqlite4GenerateConstraintChecks(
        pParse, pTab, iCur, regNew, aRegIdx, 0, 1, onError, addr, 0
    );
    if( bChngPk==0 ) aRegIdx[iPk] = regOldKey;

    /* Do FK constraint checks. */

    rc = SQLITE_OK;
    pc = pOp->p2-1;
  }else if( rc==SQLITE_INEXACT ){
    assert( nShort<pProbe->n );
    rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
    if( rc==SQLITE_OK ){
      if( nKey<nShort 
       || memcmp(pProbe->z, aKey, nKey)
       || (nKey==pProbe->n && 0==memcmp(pProbe->z, aKey, nKey))
      ){
        pc = pOp->p2-1;
      }
    }
  }

    rc = SQLITE_OK;
    pc = pOp->p2-1;
  }else if( rc==SQLITE_INEXACT ){
    assert( nShort<pProbe->n );
    rc = sqlite4KVCursorKey(pC->pKVCur, &aKey, &nKey);
    if( rc==SQLITE_OK ){
      if( nKey<nShort 
       || memcmp(pProbe->z, aKey, nShort)
       || (nKey==pProbe->n && 0==memcmp(pProbe->z, aKey, nKey))
      ){
        pc = pOp->p2-1;
      }
    }
  }

    }
    pColl = sqlite4ExprCollSeq(pParse, pExpr);
    if( !pColl ){
      pColl = db->pDfltColl;
    }
    if( pIdx->zName && i<pIdx->nColumn ){
      iColumn = pIdx->aiColumn[i];
      if( iColumn==pIdx->pTable->iPKey ){
        iColumn = -1;
      }
      iSortOrder = pIdx->aSortOrder[i];
      zColl = pIdx->azColl[i];
    }else{
      iColumn = -1;
      iSortOrder = 0;
      zColl = pColl->zName;
    }

    }
    pColl = sqlite4ExprCollSeq(pParse, pExpr);
    if( !pColl ){
      pColl = db->pDfltColl;
    }
    if( pIdx->zName && i<pIdx->nColumn ){
      iColumn = pIdx->aiColumn[i];



      iSortOrder = pIdx->aSortOrder[i];
      zColl = pIdx->azColl[i];
    }else{
      iColumn = -1;
      iSortOrder = 0;
      zColl = pColl->zName;
    }

  CREATE INDEX i1 ON t1(b);
}
do_execsql_test 10.2 {
  INSERT INTO t1 VALUES(1, 2);
  INSERT INTO t1 VALUES(3, 4);
}

# explain { UPDATE t1 SET b = 10 WHERE a=3 }
#  execsql { PRAGMA vdbe_trace = 1 }





do_execsql_test 10.3 { 
  UPDATE t1 SET b = 10 WHERE a=3;
  SELECT * FROM t1;
} {1 2 3 10}



do_execsql_test 10.4 { PRAGMA integrity_check } {ok}
execsql { PRAGMA kvdump }





finish_test

#proc populate_t1 {} {
#  db eval {
#    INSERT INTO t1(a, b) VALUES(4, 'four');
#    INSERT INTO t1(a, b) VALUES(9, 'nine');

  CREATE INDEX i1 ON t1(b);
}
do_execsql_test 10.2 {
  INSERT INTO t1 VALUES(1, 2);
  INSERT INTO t1 VALUES(3, 4);
}

do_execsql_test 10.3 { UPDATE t1 SET b = 10 WHERE a=3 }
do_execsql_test 10.4 { SELECT * FROM t1 } {1 2 3 10}
do_execsql_test 10.5 { PRAGMA integrity_check } {ok}

#-------------------------------------------------------------------------
reset_db

do_execsql_test 11.1 {



  CREATE TABLE t1(a, b, c, UNIQUE(a));
  INSERT INTO t1 VALUES(1,2,3);
}


do_catchsql_test 11.2 { 
  INSERT INTO t1 VALUES(1,2,4)
} {1 {column a is not unique}}


finish_test

#proc populate_t1 {} {
#  db eval {
#    INSERT INTO t1(a, b) VALUES(4, 'four');
#    INSERT INTO t1(a, b) VALUES(9, 'nine');