SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.426 2009/04/08 13:51:51 drh Exp $
*/
#include "sqliteInt.h"

/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,

      VdbeComment((v, "OPT: tab%d.col%d -> r%d", iTable, iColumn, p->iReg));
#endif
      return p->iReg;
    }
  }  
  assert( v!=0 );
  if( iColumn<0 ){
    int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
    sqlite3VdbeAddOp2(v, op, iTable, iReg);
  }else if( pTab==0 ){
    sqlite3VdbeAddOp3(v, OP_Column, iTable, iColumn, iReg);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite3VdbeAddOp3(v, op, iTable, iColumn, iReg);
    sqlite3ColumnDefault(v, pTab, iColumn);
#ifndef SQLITE_OMIT_FLOATING_POINT

**    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.c,v 1.196 2009/02/28 10:47:42 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */

  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0,
                             WHERE_ONEPASS_DESIRED, 0);
  if( pWInfo==0 ) goto update_cleanup;
  okOnePass = pWInfo->okOnePass;

  /* Remember the rowid of every item to be updated.
  */
  sqlite3VdbeAddOp2(v, IsVirtual(pTab)?OP_VRowid:OP_Rowid, iCur, regOldRowid);
  if( !okOnePass ){
    regRowSet = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
  }

  /* End the database scan loop.
  */

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.838 2009/04/22 15:32:59 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_SeekXX, OP_Next, or OP_Prev opcodes.  The test

  break;
}

/* Opcode: Rowid P1 P2 * * *
**
** Store in register P2 an integer which is the key of the table entry that
** P1 is currently point to.




*/
case OP_Rowid: {                 /* out2-prerelease */
  int i = pOp->p1;
  VdbeCursor *pC;
  i64 v;

  assert( i>=0 && i<p->nCursor );
  pC = p->apCsr[i];
  assert( pC!=0 );



  if( pC->deferredMoveto ){
    v = pC->movetoTarget;
















  }else{
    rc = sqlite3VdbeCursorMoveto(pC);
    if( rc ) goto abort_due_to_error;
    if( pC->rowidIsValid ){
      v = pC->lastRowid;
    }else if( pC->pseudoTable ){
      v = keyToInt(pC->iKey);
    }else if( pC->nullRow ){
      /* Leave the rowid set to a NULL */
      break;
    }else{
      assert( pC->pCursor!=0 );
      sqlite3BtreeKeySize(pC->pCursor, &v);
      v = keyToInt(v);
    }
  }
  pOut->u.i = v;

      pc = pOp->p2 - 1;
    }
  }
  pCur->nullRow = 0;

  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VRowid P1 P2 * * *
**
** Store into register P2  the rowid of
** the virtual-table that the P1 cursor is pointing to.
*/
case OP_VRowid: {             /* out2-prerelease */
  sqlite3_vtab *pVtab;
  const sqlite3_module *pModule;
  sqlite_int64 iRow;
  VdbeCursor *pCur = p->apCsr[pOp->p1];

  assert( pCur->pVtabCursor );
  if( pCur->nullRow ){
    break;
  }
  pVtab = pCur->pVtabCursor->pVtab;
  pModule = pVtab->pModule;
  assert( pModule->xRowid );
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  rc = pModule->xRowid(pCur->pVtabCursor, &iRow);
  sqlite3DbFree(db, p->zErrMsg);
  p->zErrMsg = pVtab->zErrMsg;
  pVtab->zErrMsg = 0;
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  MemSetTypeFlag(pOut, MEM_Int);
  pOut->u.i = iRow;
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VColumn P1 P2 P3 * *
**
** Store the value of the P2-th column of
** the row of the virtual-table that the 

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.386 2009/04/22 15:32:59 drh Exp $
*/
#include "sqliteInt.h"

/*
** Trace output macros
*/
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)

    assert( regRowSet>0 );
    if( iRowidReg==0 ){
      /* The rowid was not available as a side-effect of the code 
      ** genenerated above. So extract it from the cursor now.
      */
      assert( iReleaseReg==0 );
      iReleaseReg = iRowidReg = sqlite3GetTempReg(pParse);
#ifndef SQLITE_OMIT_VIRTUALTABLE
      if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
        sqlite3VdbeAddOp2(v, OP_VRowid, iCur, iRowidReg);
      }else
#endif
      {
        sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
      }
    }
    
    if( pWInfo->wctrlFlags&WHERE_FILL_ROWSET ){
      sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, iRowidReg);
      VVA_ONLY( pWInfo->iRowidHandler = 0; )
    }else{
      assert( pWInfo->wctrlFlags&WHERE_FILL_ROWTEST );