/* If we are trying to delete from a view, realize that view into
  ** a ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, pWhere, iTabCur);

  }
#endif

  /* Resolve the column names in the WHERE clause.
  */
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pParse;

  /* If we are trying to delete from a view, realize that view into
  ** a ephemeral table.
  */
#if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER)
  if( isView ){
    sqlite3MaterializeView(pParse, pTab, pWhere, iTabCur);
    iDataCur = iIdxCur = iTabCur;
  }
#endif

  /* Resolve the column names in the WHERE clause.
  */
  memset(&sNC, 0, sizeof(sNC));
  sNC.pParse = pParse;

      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */
      sqlite3GenerateConstraintChecks(pParse, pTab, iDataCur, iIdxCur,
          regIns, aRegIdx, ipkColumn>=0, 0, onError, endOfLoop, &isReplace
      );
      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
                               regIns, aRegIdx, 0, appendFlag, isReplace==0);
    }
  }

................................................................................
** the data to be inserted or the data after the update.  There will be
** pTab->nCol+1 registers in this range.  The first register (the one
** that regNewData points to) will contain the new rowid, or NULL in the
** case of a WITHOUT ROWID table.  The second register in the range will
** contain the content of the first table column.  The third register will
** contain the content of the second table column.  And so forth.
**
** For an UPDATE (isUpdate!=0), if pkChng is non-zero then it contains
** the address of a range of registers containing the rowid and table
** data from before the change.  In other words, pkChng is like 
** regNewData except that it describes the row before the update rather
** than afterwards.  If pkChng is zero, that means that the rowid does 
** not change (for a normal rowid table) or the PRIMARY KEY does not
** change (for a WITHOUT ROWID table) in which case the old data is
** not needed.

**
** For an INSERT (isUpdate==0), pkChng is just a boolean that indicates

** whether or not the rowid was explicitly specified as part of the
** INSERT statement.  If pkChng is zero, it means that the either rowid
** is computed automatically or that the table is a WITHOUT ROWID table
** and has no rowid.  On an INSERT, pkChng will only be true if the
** INSERT statement provides an integer value for either the rowid
** column or its INTEGER PRIMARY KEY alias.
**
** The code generated by this routine will store new index entries into
** registers identified by aRegIdx[].  No index entry is created for
** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
** the same as the order of indices on the linked list of indices
** at pTab->pIndex.
**
................................................................................
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used.  Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
*/
void sqlite3GenerateConstraintChecks(
  Parse *pParse,       /* The parser context */
  Table *pTab,         /* The table being inserted or updated */

  int iDataCur,        /* Canonical data cursor (main table or PK index) */
  int iIdxCur,         /* First index cursor */
  int regNewData,      /* First register in a range holding values to insert */
  int *aRegIdx,        /* Register used by each index.  0 for unused indices */
  int pkChng,          /* Non-zero if the rowid or PRIMARY KEY changed */
  int isUpdate,        /* True for UPDATE, False for INSERT */
  int overrideError,   /* Override onError to this if not OE_Default */
  int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
  int *pbMayReplace    /* OUT: Set to true if constraint may cause a replace */
){
  int i;               /* loop counter */
  Vdbe *v;             /* VDBE under constrution */
  int nCol;            /* Number of columns */
  int onError;         /* Conflict resolution strategy */
  int j1;              /* Addresss of jump instruction */
  int ix;              /* Index loop counter */
  Index *pIdx;         /* Pointer to one of the indices */
  Index *pPk = 0;      /* The PRIMARY KEY index */
  sqlite3 *db;         /* Database connection */





  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */
  int regOldData;      /* Previous rowid and table data */
  int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */


  regOldData = (pkChng && isUpdate) ? pkChng : regNewData;

  db = pParse->db;
  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  nCol = pTab->nCol;
  
  /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
................................................................................
                              onError, zConsName, P4_DYNAMIC);
      }
      sqlite3VdbeResolveLabel(v, allOk);
    }
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* If there is an INTEGER PRIMARY KEY, make sure the primary key
  ** of the new record does not previously exist.  Except, if this
  ** is an UPDATE and the primary key is not changing, then obviously
  ** it is OK for the previous rowid to exist in that case.
  **
  ** This block only runs for tables that have a rowid.
  */
  if( pkChng && pPk==0 ){
    int addrRowidOk = sqlite3VdbeMakeLabel(v);


    onError = pTab->keyConf;
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }

    if( isUpdate ){



      sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
    }



    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);


    switch( onError ){
      default: {
        onError = OE_Abort;
        /* Fall thru into the next case */
      }
      case OE_Rollback:
      case OE_Abort:
................................................................................
    }
    sqlite3VdbeResolveLabel(v, addrRowidOk);
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Compute the revised record entries for indices as we go.



  */
  for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){
    int regIdx;          /* Range of registers hold conent for pIdx */
    int regR;            /* Range of registers holding conflicting PK */
    int iThisCur;        /* Cursor for this UNIQUE index */
    int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */

    if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
    iThisCur = iIdxCur+ix;
    addrUniqueOk = sqlite3VdbeMakeLabel(v);


    if( pIdx->pPartIdxWhere ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
      pParse->ckBase = regNewData+1;
      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
                         SQLITE_JUMPIFNULL);
      pParse->ckBase = 0;
    }

    /* Create a record for this index entry as it should appear after
    ** the insert or update. */

    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
    for(i=0; i<pIdx->nColumn; i++){
      int iField = pIdx->aiColumn[i];
      int x;
      if( iField<0 || iField==pTab->iPKey ){
        x = regNewData;
      }else{
................................................................................
      sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
      VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
    }
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
    sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
    VdbeComment((v, "for %s", pIdx->zName));
    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn);







    /* Find out what action to take in case there is a uniqueness conflict */
    onError = pIdx->onError;
    if( onError==OE_None ){ 
      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
      sqlite3VdbeResolveLabel(v, addrUniqueOk);
      continue;  /* pIdx is not a UNIQUE index */
................................................................................
      else if( onError==OE_Fail ) onError = OE_Abort;
    }
    
    /* Check to see if the new index entry will be unique */
    regR = sqlite3GetTempRange(pParse, nPkField);
    sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
                         regIdx, pIdx->nKeyCol);


    if( HasRowid(pTab) ){
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
      /* Conflict only if the rowid of the existing index entry
      ** is different from old-rowid */

      sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);

    }else{
      int x;
      /* Extract the PRIMARY KEY from the end of the index entry and
      ** store it in register regR..regR+nPk-1 */
      for(i=0; i<pPk->nKeyCol; i++){
        x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
        sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);

      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, regIns, pVTab, P4_VTAB);
      sqlite3VdbeChangeP5(v, onError==OE_Default ? OE_Abort : onError);
      sqlite3MayAbort(pParse);
    }else
#endif
    {
      int isReplace;    /* Set to true if constraints may cause a replace */
      sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
          regIns, 0, ipkColumn>=0, onError, endOfLoop, &isReplace
      );
      sqlite3FkCheck(pParse, pTab, 0, regIns, 0, 0);
      sqlite3CompleteInsertion(pParse, pTab, iDataCur, iIdxCur,
                               regIns, aRegIdx, 0, appendFlag, isReplace==0);
    }
  }

................................................................................
** the data to be inserted or the data after the update.  There will be
** pTab->nCol+1 registers in this range.  The first register (the one
** that regNewData points to) will contain the new rowid, or NULL in the
** case of a WITHOUT ROWID table.  The second register in the range will
** contain the content of the first table column.  The third register will
** contain the content of the second table column.  And so forth.
**
** The regOldData parameter is similar to regNewData except that it contains
** the data prior to an UPDATE rather than afterwards.  regOldData is zero
** for an INSERT.  This routine can distinguish between UPDATE and INSERT by
** checking regOldData for zero.
**
** For an UPDATE, the pkChng boolean is true if the true primary key (the
** rowid for a normal table or the PRIMARY KEY for a WITHOUT ROWID table)
** might be modified by the UPDATE.  If pkChng is false, then the key of
** the iDataCur content table is guaranteed to be unchanged by the UPDATE.
**

** For an INSERT, the pkChng boolean indicates whether or not the rowid
** was explicitly specified as part of the INSERT statement.  If pkChng
** is zero, it means that the either rowid is computed automatically or
** that the table is a WITHOUT ROWID table and has no rowid.  On an INSERT,

** pkChng will only be true if the INSERT statement provides an integer
** value for either the rowid column or its INTEGER PRIMARY KEY alias.
**
** The code generated by this routine will store new index entries into
** registers identified by aRegIdx[].  No index entry is created for
** indices where aRegIdx[i]==0.  The order of indices in aRegIdx[] is
** the same as the order of indices on the linked list of indices
** at pTab->pIndex.
**
................................................................................
** Or if overrideError==OE_Default, then the pParse->onError parameter
** is used.  Or if pParse->onError==OE_Default then the onError value
** for the constraint is used.
*/
void sqlite3GenerateConstraintChecks(
  Parse *pParse,       /* The parser context */
  Table *pTab,         /* The table being inserted or updated */
  int *aRegIdx,        /* Use register aRegIdx[i] for index i.  0 for unused */
  int iDataCur,        /* Canonical data cursor (main table or PK index) */
  int iIdxCur,         /* First index cursor */
  int regNewData,      /* First register in a range holding values to insert */
  int regOldData,      /* Previous content.  0 for INSERTs */
  u8 pkChng,           /* Non-zero if the rowid or PRIMARY KEY changed */

  u8 overrideError,    /* Override onError to this if not OE_Default */
  int ignoreDest,      /* Jump to this label on an OE_Ignore resolution */
  int *pbMayReplace    /* OUT: Set to true if constraint may cause a replace */
){

  Vdbe *v;             /* VDBE under constrution */




  Index *pIdx;         /* Pointer to one of the indices */
  Index *pPk = 0;      /* The PRIMARY KEY index */
  sqlite3 *db;         /* Database connection */
  int i;               /* loop counter */
  int ix;              /* Index loop counter */
  int nCol;            /* Number of columns */
  int onError;         /* Conflict resolution strategy */
  int j1;              /* Addresss of jump instruction */
  int seenReplace = 0; /* True if REPLACE is used to resolve INT PK conflict */

  int nPkField;        /* Number of fields in PRIMARY KEY. 1 for ROWID tables */
  u8 isUpdate;


  isUpdate = regOldData!=0;
  db = pParse->db;
  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  nCol = pTab->nCol;
  
  /* pPk is the PRIMARY KEY index for WITHOUT ROWID tables and NULL for
................................................................................
                              onError, zConsName, P4_DYNAMIC);
      }
      sqlite3VdbeResolveLabel(v, allOk);
    }
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* If rowid is changing, make sure the new rowid does not previously
  ** exist in the table.




  */
  if( pkChng && pPk==0 ){
    int addrRowidOk = sqlite3VdbeMakeLabel(v);

    /* Figure out what action to take in case of a rowid collision */
    onError = pTab->keyConf;
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }

    if( isUpdate ){
      /* pkChng!=0 does not mean that the rowid has change, only that
      ** it might have changed.  Skip the conflict logic below if the rowid
      ** is unchanged. */
      sqlite3VdbeAddOp3(v, OP_Eq, regNewData, addrRowidOk, regOldData);
    }

    /* Check to see if the new rowid already exists in the table.  Skip
    ** the following conflict logic if it does not. */
    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, addrRowidOk, regNewData);

    /* Generate code that deals with a rowid collision */
    switch( onError ){
      default: {
        onError = OE_Abort;
        /* Fall thru into the next case */
      }
      case OE_Rollback:
      case OE_Abort:
................................................................................
    }
    sqlite3VdbeResolveLabel(v, addrRowidOk);
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Compute the revised record entries for indices as we go.
  **
  ** This loop also handles the case of the PRIMARY KEY index for a
  ** WITHOUT ROWID table.
  */
  for(ix=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, ix++){
    int regIdx;          /* Range of registers hold conent for pIdx */
    int regR;            /* Range of registers holding conflicting PK */
    int iThisCur;        /* Cursor for this UNIQUE index */
    int addrUniqueOk;    /* Jump here if the UNIQUE constraint is satisfied */

    if( aRegIdx[ix]==0 ) continue;  /* Skip indices that do not change */
    iThisCur = iIdxCur+ix;
    addrUniqueOk = sqlite3VdbeMakeLabel(v);

    /* Skip partial indices for which the WHERE clause is not true */
    if( pIdx->pPartIdxWhere ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[ix]);
      pParse->ckBase = regNewData+1;
      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, addrUniqueOk,
                         SQLITE_JUMPIFNULL);
      pParse->ckBase = 0;
    }

    /* Create a record for this index entry as it should appear after
    ** the insert or update.  Store that record in the aRegIdx[ix] register
    */
    regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
    for(i=0; i<pIdx->nColumn; i++){
      int iField = pIdx->aiColumn[i];
      int x;
      if( iField<0 || iField==pTab->iPKey ){
        x = regNewData;
      }else{
................................................................................
      sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
      VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
    }
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
    sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);
    VdbeComment((v, "for %s", pIdx->zName));
    sqlite3ExprCacheAffinityChange(pParse, regIdx, pIdx->nColumn);

    /* In an UPDATE operation, if this index is the PRIMARY KEY index 
    ** of a WITHOUT ROWID table and there has been no change the
    ** primary key, then no collision is possible.  The collision detection
    ** logic below can all be skipped. */
    if( isUpdate && pPk && pkChng==0 ) continue;

    /* Find out what action to take in case there is a uniqueness conflict */
    onError = pIdx->onError;
    if( onError==OE_None ){ 
      sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn);
      sqlite3VdbeResolveLabel(v, addrUniqueOk);
      continue;  /* pIdx is not a UNIQUE index */
................................................................................
      else if( onError==OE_Fail ) onError = OE_Abort;
    }
    
    /* Check to see if the new index entry will be unique */
    regR = sqlite3GetTempRange(pParse, nPkField);
    sqlite3VdbeAddOp4Int(v, OP_NoConflict, iThisCur, addrUniqueOk,
                         regIdx, pIdx->nKeyCol);

    /* Generate code to handle collisions */
    if( HasRowid(pTab) ){
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iThisCur, regR);
      /* Conflict only if the rowid of the existing index entry
      ** is different from old-rowid */
      if( isUpdate ){
        sqlite3VdbeAddOp3(v, OP_Eq, regR, addrUniqueOk, regOldData);
      }
    }else{
      int x;
      /* Extract the PRIMARY KEY from the end of the index entry and
      ** store it in register regR..regR+nPk-1 */
      for(i=0; i<pPk->nKeyCol; i++){
        x = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[i]);
        sqlite3VdbeAddOp3(v, OP_Column, iThisCur, x, regR+i);

int sqlite3ExprCanBeNull(const Expr*);
void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(Parse*,Table*,Trigger*,int,int,int,i16,u8,u8);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,int,
                                     int*,int,int,int,int,int*);
void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
int sqlite3OpenTableAndIndices(Parse*, Table*, int, int, int*, int*);
void sqlite3BeginWriteOperation(Parse*, int, int);
void sqlite3MultiWrite(Parse*);
void sqlite3MayAbort(Parse*);
void sqlite3HaltConstraint(Parse*, int, int, char*, int);
Expr *sqlite3ExprDup(sqlite3*,Expr*,int);

int sqlite3ExprCanBeNull(const Expr*);
void sqlite3ExprCodeIsNullJump(Vdbe*, const Expr*, int, int);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(Parse*,Table*,Trigger*,int,int,int,i16,u8,u8);
void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int, int*);
int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int*,int,int,int,int,
                                     u8,u8,int,int*);
void sqlite3CompleteInsertion(Parse*,Table*,int,int,int,int*,int,int,int);
int sqlite3OpenTableAndIndices(Parse*, Table*, int, int, int*, int*);
void sqlite3BeginWriteOperation(Parse*, int, int);
void sqlite3MultiWrite(Parse*);
void sqlite3MayAbort(Parse*);
void sqlite3HaltConstraint(Parse*, int, int, char*, int);
Expr *sqlite3ExprDup(sqlite3*,Expr*,int);

  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. */
  int chngPk;            /* True if the rowid or PRIMARY KEY is 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 */
................................................................................
  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.  Set chngPk if the iDataCur key changes.  Note that
  ** for WITHOUT ROWID columns, the iDataCur key contains all columns of
  ** the table and so it will always change.
  */
  chngPk = (pPk!=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 ){
          chngPk = 1;
          pRowidExpr = pChanges->a[i].pExpr;


        }
        aXRef[j] = i;
        break;
      }
    }
    if( j>=pTab->nCol ){
      if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){
        j = -1;
        chngPk = 1;
        pRowidExpr = pChanges->a[i].pExpr;
      }else{
        sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName);
        pParse->checkSchema = 1;
        goto update_cleanup;
      }
    }
................................................................................
        goto update_cleanup;
      }else if( rc==SQLITE_IGNORE ){
        aXRef[j] = -1;
      }
    }
#endif
  }





  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngPk);

  /* 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.
  */
  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 || chngPk || pIdx->pPartIdxWhere ){
      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;
................................................................................
    goto update_cleanup;
  }
#endif

  /* Allocate required registers. */
  regRowSet = ++pParse->nMem;
  regOldRowid = regNewRowid = ++pParse->nMem;
  if( pTrigger || hasFK ){
    regOld = pParse->nMem + 1;
    pParse->nMem += pTab->nCol;
  }
  if( chngPk || pTrigger || hasFK ){
    regNewRowid = ++pParse->nMem;
  }
  regNew = pParse->nMem + 1;
  pParse->nMem += pTab->nCol;

  /* Start the view context. */
  if( isView ){
................................................................................
    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 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( chngPk || pTrigger || hasFK || regOldRowid==regNewRowid );
  if( chngPk && pPk==0 ){
    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, iDataCur, i, regOld+i);
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i);
      }
    }
    if( chngPk==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
................................................................................

    /* 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.
    */



    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 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( !isView ){
    int j1;                       /* Address of jump instruction */

    /* Do constraint checks. */
    sqlite3GenerateConstraintChecks(pParse, pTab, iDataCur, iIdxCur,
        regNewRowid, aRegIdx, (chngPk?regOldRowid:0), 1, onError, addr, 0);


    /* Do FK constraint checks. */
    if( hasFK ){
      sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngPk);
    }

    /* Delete the index entries associated with the current record.  */
    if( pPk ){
      j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, 0);
    }else{
      j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
    }
    sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx);
  
    /* If changing the record number, delete the old record.  */
    if( hasFK || chngPk ){
      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
    }
    if( sqlite3VdbeCurrentAddr(v)==j1+1 ){
      sqlite3VdbeChangeToNoop(v, j1);
    }else{
      sqlite3VdbeJumpHere(v, j1);
    }

    if( hasFK ){
      sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngPk);
    }
  
    /* 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, chngPk);
    }
  }

  /* Increment the row counter 
  */
  if( (db->flags & SQLITE_CountRows) && !pParse->pTriggerTab){
    sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1);

  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 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 */
  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 */
................................................................................
  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;
      }
    }
................................................................................
        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;

  hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey);

  /* 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.
  */
  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( 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;
        }
      }
    }
    aRegIdx[j] = reg;
................................................................................
    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 ){
................................................................................
    sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 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( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid );
  if( chngRowid ){
    sqlite3ExprCode(pParse, pRowidExpr, regNewRowid);
    sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid);
  }

  /* 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 & (1<<i)))
       || (chngPk && (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0)
      ){
        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
................................................................................

    /* 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, 0);
    }else{
      sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 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( !isView ){
    int j1;                       /* Address of jump instruction */

    /* Do constraint checks. */
    assert( regOldRowid>0 );
    sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur,
        regNewRowid, regOldRowid, chngKey, onError, addr, 0);

    /* Do FK constraint checks. */
    if( hasFK ){
      sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey);
    }

    /* Delete the index entries associated with the current record.  */
    if( pPk ){
      j1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, 0);
    }else{
      j1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid);
    }
    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( sqlite3VdbeCurrentAddr(v)==j1+1 ){
      sqlite3VdbeChangeToNoop(v, j1);
    }else{
      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);

# REPLACE INTO works, however.
#
do_execsql_test without_rowid1-1.22 {
  REPLACE INTO t1 VALUES('dynamic','phone','flipper','harvard');
  SELECT *, '|' FROM t1 ORDER BY c, a;
} {arctic sleep ammonia helena | journal sherman ammonia helena | dynamic phone flipper harvard | journal sherman gamma patriot |}












finish_test

# REPLACE INTO works, however.
#
do_execsql_test without_rowid1-1.22 {
  REPLACE INTO t1 VALUES('dynamic','phone','flipper','harvard');
  SELECT *, '|' FROM t1 ORDER BY c, a;
} {arctic sleep ammonia helena | journal sherman ammonia helena | dynamic phone flipper harvard | journal sherman gamma patriot |}

do_execsql_test without_rowid1-1.23 {
  SELECT *, '|' FROM t1 ORDER BY b, d;
} {dynamic phone flipper harvard | journal sherman ammonia helena | journal sherman gamma patriot | arctic sleep ammonia helena |}

# UPDATE statements.
#
do_execsql_test without_rowid1-1.31 {
  UPDATE t1 SET d=3.1415926 WHERE a='journal';
  SELECT *, '|' FROM t1 ORDER BY c, a;
} {arctic sleep ammonia helena | journal sherman ammonia 3.1415926 | dynamic phone flipper harvard | journal sherman gamma 3.1415926 |}

finish_test