**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.186 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs
................................................................................
    {"CHAR", 4, SQLITE_AFF_TEXT},
    {"CLOB", 4, SQLITE_AFF_TEXT},
    {"TEXT", 4, SQLITE_AFF_TEXT}
  };

  for(n=0; n<(nType-2); n++){
    for(i=0; i<sizeof(substrings)/sizeof(substrings[0]); i++){
      if( 0==sqlite3StrNICmp(zType, substrings[i].zSub, substrings[i].nSub) ){
        return substrings[i].affinity;
      }
    }
  }

  return SQLITE_AFF_NONE;
}
................................................................................
      sqlite3VdbeChangeP3(v, -1, z, n);
      sqliteFree(z);
    }else{
      assert( pEnd!=0 );
      n = Addr(pEnd->z) - Addr(pParse->sFirstToken.z) + 1;
      sqlite3VdbeChangeP3(v, -1, pParse->sFirstToken.z, n);
    }
    sqlite3VdbeAddOp(v, OP_MakeRecord, 5, 0);
    sqlite3VdbeAddOp(v, OP_PutIntKey, 0, 0);
    if( !p->iDb ){
      sqlite3ChangeCookie(db, v);
    }
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    if( pSelect ){
      sqlite3VdbeAddOp(v, OP_Integer, p->iDb, 0);
      sqlite3VdbeAddOp(v, OP_OpenWrite, 1, 0);
      pParse->nTab = 2;
      sqlite3Select(pParse, pSelect, SRT_Table, 1, 0, 0, 0);
    }
    sqlite3EndWriteOperation(pParse);
  }

  /* Add the table to the in-memory representation of the database.
  */
  if( pParse->explain==0 && pParse->nErr==0 ){
................................................................................
      0);
    }
    addr = sqlite3VdbeAddOp(v, OP_String, 0, 0);
    if( pStart && pEnd ){
      n = Addr(pEnd->z) - Addr(pStart->z) + 1;
      sqlite3VdbeChangeP3(v, addr, pStart->z, n);
    }
    sqlite3VdbeAddOp(v, OP_MakeRecord, 5, 0);
    sqlite3VdbeAddOp(v, OP_PutIntKey, 0, 0);
    if( pTable ){
      sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
      sqlite3VdbeOp3(v, OP_OpenRead, 2, pTab->tnum, pTab->zName, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, 2, pTab->nCol);
      lbl2 = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeAddOp(v, OP_Rewind, 2, lbl2);

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.187 2004/05/18 09:58:07 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs
................................................................................
    {"CHAR", 4, SQLITE_AFF_TEXT},
    {"CLOB", 4, SQLITE_AFF_TEXT},
    {"TEXT", 4, SQLITE_AFF_TEXT}
  };

  for(n=0; n<(nType-2); n++){
    for(i=0; i<sizeof(substrings)/sizeof(substrings[0]); i++){
      if( 0==sqlite3StrNICmp(&zType[n], substrings[i].zSub, substrings[i].nSub) ){
        return substrings[i].affinity;
      }
    }
  }

  return SQLITE_AFF_NONE;
}
................................................................................
      sqlite3VdbeChangeP3(v, -1, z, n);
      sqliteFree(z);
    }else{
      assert( pEnd!=0 );
      n = Addr(pEnd->z) - Addr(pParse->sFirstToken.z) + 1;
      sqlite3VdbeChangeP3(v, -1, pParse->sFirstToken.z, n);
    }
    sqlite3VdbeOp3(v, OP_MakeRecord, 5, 0, "tttit", P3_STATIC);
    sqlite3VdbeAddOp(v, OP_PutIntKey, 0, 0);
    if( !p->iDb ){
      sqlite3ChangeCookie(db, v);
    }
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    if( pSelect ){
      sqlite3VdbeAddOp(v, OP_Integer, p->iDb, 0);
      sqlite3VdbeAddOp(v, OP_OpenWrite, 1, 0);
      pParse->nTab = 2;
      sqlite3Select(pParse, pSelect, SRT_Table, 1, 0, 0, 0, 0);
    }
    sqlite3EndWriteOperation(pParse);
  }

  /* Add the table to the in-memory representation of the database.
  */
  if( pParse->explain==0 && pParse->nErr==0 ){
................................................................................
      0);
    }
    addr = sqlite3VdbeAddOp(v, OP_String, 0, 0);
    if( pStart && pEnd ){
      n = Addr(pEnd->z) - Addr(pStart->z) + 1;
      sqlite3VdbeChangeP3(v, addr, pStart->z, n);
    }
    sqlite3VdbeOp3(v, OP_MakeRecord, 5, 0, "tttit", P3_STATIC);
    sqlite3VdbeAddOp(v, OP_PutIntKey, 0, 0);
    if( pTable ){
      sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
      sqlite3VdbeOp3(v, OP_OpenRead, 2, pTab->tnum, pTab->zName, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, 2, pTab->nCol);
      lbl2 = sqlite3VdbeMakeLabel(v);
      sqlite3VdbeAddOp(v, OP_Rewind, 2, lbl2);

**    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 DELETE FROM statements.
**
** $Id: delete.c,v 1.66 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
  sqlite3BeginWriteOperation(pParse, row_triggers_exist, pTab->iDb);

  /* If we are trying to delete from a view, construct that view into
  ** a temporary table.
  */
  if( isView ){
    Select *pView = sqlite3SelectDup(pTab->pSelect);
    sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0);
    sqlite3SelectDelete(pView);
  }

  /* Initialize the counter of the number of rows deleted, if
  ** we are counting rows.
  */
  if( db->flags & SQLITE_CountRows ){
................................................................................
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( row_triggers_exist ){
      sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);

    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);

**    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 DELETE FROM statements.
**
** $Id: delete.c,v 1.67 2004/05/18 09:58:07 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
  sqlite3BeginWriteOperation(pParse, row_triggers_exist, pTab->iDb);

  /* If we are trying to delete from a view, construct that view into
  ** a temporary table.
  */
  if( isView ){
    Select *pView = sqlite3SelectDup(pTab->pSelect);
    sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0, 0);
    sqlite3SelectDelete(pView);
  }

  /* Initialize the counter of the number of rows deleted, if
  ** we are counting rows.
  */
  if( db->flags & SQLITE_CountRows ){
................................................................................
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( row_triggers_exist ){
      sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);

**    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 INSERT statements in SQLite.
**
** $Id: insert.c,v 1.101 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
................................................................................
  if( pSelect ){
    /* Data is coming from a SELECT.  Generate code to implement that SELECT
    */
    int rc, iInitCode;
    iInitCode = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    iSelectLoop = sqlite3VdbeCurrentAddr(v);
    iInsertBlock = sqlite3VdbeMakeLabel(v);
    rc = sqlite3Select(pParse, pSelect, SRT_Subroutine, iInsertBlock, 0,0,0);
    if( rc || pParse->nErr || sqlite3_malloc_failed ) goto insert_cleanup;
    iCleanup = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Goto, 0, iCleanup);
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement
................................................................................
    ** A temp table must be used if the table being updated is also one
    ** of the tables being read by the SELECT statement.  Also use a 
    ** temp table in the case of row triggers.
    */
    if( row_triggers_exist ){
      useTempTable = 1;
    }else{
      int addr = sqlite3VdbeFindOp(v, OP_OpenRead, pTab->tnum);
      useTempTable = 0;
      if( addr>0 ){
        VdbeOp *pOp = sqlite3VdbeGetOp(v, addr-2);
        if( pOp->opcode==OP_Integer && pOp->p1==pTab->iDb ){
          useTempTable = 1;
        }
      }
................................................................................
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( row_triggers_exist ){
    sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);

  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    iCntMem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);

**    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 INSERT statements in SQLite.
**
** $Id: insert.c,v 1.102 2004/05/18 09:58:07 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
................................................................................
  if( pSelect ){
    /* Data is coming from a SELECT.  Generate code to implement that SELECT
    */
    int rc, iInitCode;
    iInitCode = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    iSelectLoop = sqlite3VdbeCurrentAddr(v);
    iInsertBlock = sqlite3VdbeMakeLabel(v);
    rc = sqlite3Select(pParse, pSelect, SRT_Subroutine, iInsertBlock, 0,0,0,0);
    if( rc || pParse->nErr || sqlite3_malloc_failed ) goto insert_cleanup;
    iCleanup = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Goto, 0, iCleanup);
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement
................................................................................
    ** A temp table must be used if the table being updated is also one
    ** of the tables being read by the SELECT statement.  Also use a 
    ** temp table in the case of row triggers.
    */
    if( row_triggers_exist ){
      useTempTable = 1;
    }else{
      int addr = sqlite3VdbeFindOp(v, 0, OP_OpenRead, pTab->tnum);
      useTempTable = 0;
      if( addr>0 ){
        VdbeOp *pOp = sqlite3VdbeGetOp(v, addr-2);
        if( pOp->opcode==OP_Integer && pOp->p1==pTab->iDb ){
          useTempTable = 1;
        }
      }
................................................................................
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( row_triggers_exist ){
    sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    iCntMem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);

**    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 code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.24 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Interpret the given string as a boolean value.
*/
................................................................................
    for(i=0; i<db->nDb; i++){
      HashElem *x;

      /* Do an integrity check of the B-Tree
      */
      addr = sqlite3VdbeAddOpList(v, ArraySize(checkDb), checkDb);
      sqlite3VdbeChangeP1(v, addr+1, i);
      sqlite3VdbeChangeP2(v, addr+3, addr+7);
      sqlite3VdbeChangeP2(v, addr+6, addr+4);
      sqlite3VdbeChangeP2(v, addr+7, i);
      sqlite3VdbeChangeP2(v, addr+10, addr+ArraySize(checkDb));
      sqlite3VdbeChangeP3(v, addr+13, db->aDb[i].zName, P3_STATIC);

      /* Make sure all the indices are constructed correctly.
      */
      sqlite3CodeVerifySchema(pParse, i);
      for(x=sqliteHashFirst(&db->aDb[i].tblHash); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;

**    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 code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.25 2004/05/18 09:58:08 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Interpret the given string as a boolean value.
*/
................................................................................
    for(i=0; i<db->nDb; i++){
      HashElem *x;

      /* Do an integrity check of the B-Tree
      */
      addr = sqlite3VdbeAddOpList(v, ArraySize(checkDb), checkDb);
      sqlite3VdbeChangeP1(v, addr+1, i);
      sqlite3VdbeChangeP2(v, addr+4, addr+8);
      sqlite3VdbeChangeP2(v, addr+7, addr+5);
      sqlite3VdbeChangeP2(v, addr+8, i);
      sqlite3VdbeChangeP2(v, addr+11, addr+ArraySize(checkDb));
      sqlite3VdbeChangeP3(v, addr+14, db->aDb[i].zName, P3_STATIC);

      /* Make sure all the indices are constructed correctly.
      */
      sqlite3CodeVerifySchema(pParse, i);
      for(x=sqliteHashFirst(&db->aDb[i].tblHash); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;

**    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 SELECT statements in SQLite.
**
** $Id: select.c,v 1.166 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.
................................................................................
  int srcTab,             /* Pull data from this table */
  int nColumn,            /* Number of columns in the source table */
  ExprList *pOrderBy,     /* If not NULL, sort results using this key */
  int distinct,           /* If >=0, make sure results are distinct */
  int eDest,              /* How to dispose of the results */
  int iParm,              /* An argument to the disposal method */
  int iContinue,          /* Jump here to continue with next row */
  int iBreak              /* Jump here to break out of the inner loop */

){
  Vdbe *v = pParse->pVdbe;
  int i;

  if( v==0 ) return 0;
  assert( pEList!=0 );

................................................................................

  switch( eDest ){
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
    case SRT_Union: {
      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);

      sqlite3VdbeAddOp(v, OP_String, 0, 0);
      sqlite3VdbeAddOp(v, OP_PutStrKey, iParm, 0);
      break;
    }

    /* Store the result as data using a unique key.
    */
................................................................................
    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);

      sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
      break;
    }

    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
................................................................................
      if( pOrderBy ){
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        char const *affStr;
        char aff = (iParm>>16)&0xFF;
        aff = sqlite3CompareAffinity(pEList->a[0].pExpr, aff);
        affStr = sqlite3AffinityString(aff);
        sqlite3VdbeOp3(v, OP_MakeKey, 1, 1, affStr, P3_STATIC);
        sqlite3VdbeAddOp(v, OP_String, 0, 0);
        sqlite3VdbeAddOp(v, OP_PutStrKey, (iParm&0x0000FFFF), 0);
      }
      sqlite3VdbeChangeP2(v, addr2, sqlite3VdbeCurrentAddr(v));
      break;
    }

................................................................................
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
      sqlite3VdbeAddOp(v, OP_Goto, 0, end1);
      break;
    }
    case SRT_Subroutine: {
      int i;


      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp(v, OP_Column, -1-i, i);
      }
      sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      break;
    }
    default: {
      /* Do nothing */
      break;
    }
  }
................................................................................
    if( pE->dataType==SQLITE_SO_NUM ) continue;
    assert( pE->iColumn>=0 );
    if( pEList->nExpr>pE->iColumn ){
      pE->dataType = sqlite3ExprType(pEList->a[pE->iColumn].pExpr);
    }
  }
}














/*
** Compute the iLimit and iOffset fields of the SELECT based on the
** nLimit and nOffset fields.  nLimit and nOffset hold the integers
** that appear in the original SQL statement after the LIMIT and OFFSET
** keywords.  Or that hold -1 and 0 if those keywords are omitted.
** iLimit and iOffset are the integer memory register numbers for
................................................................................
** The arrows in the diagram above represent the Select.pPrior pointer.
** So if this routine is called with p equal to the t3 query, then
** pPrior will be the t2 query.  p->op will be TK_UNION in this case.
**
** Notice that because of the way SQLite parses compound SELECTs, the
** individual selects always group from left to right.
*/
static int multiSelect(Parse *pParse, Select *p, int eDest, int iParm){






  int rc;             /* Success code from a subroutine */
  Select *pPrior;     /* Another SELECT immediately to our left */
  Vdbe *v;            /* Generate code to this VDBE */


















  /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only
  ** the last SELECT in the series may have an ORDER BY or LIMIT.
  */
  if( p==0 || p->pPrior==0 ) return 1;



  pPrior = p->pPrior;
  if( pPrior->pOrderBy ){
    sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
      selectOpName(p->op));
    return 1;

  }
  if( pPrior->nLimit>=0 || pPrior->nOffset>0 ){
    sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before",
      selectOpName(p->op));
    return 1;

  }

  /* Make sure we have a valid query engine.  If not, create a new one.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return 1;




  /* Create the destination temporary table if necessary
  */
  if( eDest==SRT_TempTable ){
    assert( p->pEList );
    sqlite3VdbeAddOp(v, OP_OpenTemp, iParm, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, p->pEList->nExpr);
................................................................................
  /* Generate code for the left and right SELECT statements.
  */
  switch( p->op ){
    case TK_ALL: {
      if( p->pOrderBy==0 ){
        pPrior->nLimit = p->nLimit;
        pPrior->nOffset = p->nOffset;
        rc = sqlite3Select(pParse, pPrior, eDest, iParm, 0, 0, 0);
        if( rc ) return rc;


        p->pPrior = 0;
        p->iLimit = pPrior->iLimit;
        p->iOffset = pPrior->iOffset;
        p->nLimit = -1;
        p->nOffset = 0;
        rc = sqlite3Select(pParse, p, eDest, iParm, 0, 0, 0);
        p->pPrior = pPrior;
        if( rc ) return rc;


        break;
      }
      /* For UNION ALL ... ORDER BY fall through to the next case */
    }
    case TK_EXCEPT:
    case TK_UNION: {
      int unionTab;    /* Cursor number of the temporary table holding result */
................................................................................
      }else{
        /* We will need to create our own temporary table to hold the
        ** intermediate results.
        */
        unionTab = pParse->nTab++;
        if( p->pOrderBy 
        && matchOrderbyToColumn(pParse, p, p->pOrderBy, unionTab, 1) ){
          return 1;

        }
        if( p->op!=TK_ALL ){
          sqlite3VdbeAddOp(v, OP_OpenTemp, unionTab, 1);
          sqlite3VdbeAddOp(v, OP_KeyAsData, unionTab, 1);
        }else{
          sqlite3VdbeAddOp(v, OP_OpenTemp, unionTab, 0);
        }

      }

      /* Code the SELECT statements to our left
      */
      rc = sqlite3Select(pParse, pPrior, priorOp, unionTab, 0, 0, 0);
      if( rc ) return rc;






      /* Code the current SELECT statement
      */
      switch( p->op ){
         case TK_EXCEPT:  op = SRT_Except;   break;
         case TK_UNION:   op = SRT_Union;    break;
         case TK_ALL:     op = SRT_Table;    break;
................................................................................
      p->pPrior = 0;
      pOrderBy = p->pOrderBy;
      p->pOrderBy = 0;
      nLimit = p->nLimit;
      p->nLimit = -1;
      nOffset = p->nOffset;
      p->nOffset = 0;
      rc = sqlite3Select(pParse, p, op, unionTab, 0, 0, 0);
      p->pPrior = pPrior;
      p->pOrderBy = pOrderBy;
      p->nLimit = nLimit;
      p->nOffset = nOffset;
      if( rc ) return rc;




      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */      
      if( eDest!=priorOp || unionTab!=iParm ){
        int iCont, iBreak, iStart;
        assert( p->pEList );
................................................................................
        iCont = sqlite3VdbeMakeLabel(v);
        sqlite3VdbeAddOp(v, OP_Rewind, unionTab, iBreak);
        computeLimitRegisters(pParse, p);
        iStart = sqlite3VdbeCurrentAddr(v);
        multiSelectSortOrder(p, p->pOrderBy);
        rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
                             p->pOrderBy, -1, eDest, iParm, 
                             iCont, iBreak);
        if( rc ) return 1;



        sqlite3VdbeResolveLabel(v, iCont);
        sqlite3VdbeAddOp(v, OP_Next, unionTab, iStart);
        sqlite3VdbeResolveLabel(v, iBreak);
        sqlite3VdbeAddOp(v, OP_Close, unionTab, 0);
        if( p->pOrderBy ){
          generateSortTail(p, v, p->pEList->nExpr, eDest, iParm);
        }
................................................................................
      /* INTERSECT is different from the others since it requires
      ** two temporary tables.  Hence it has its own case.  Begin
      ** by allocating the tables we will need.
      */
      tab1 = pParse->nTab++;
      tab2 = pParse->nTab++;
      if( p->pOrderBy && matchOrderbyToColumn(pParse,p,p->pOrderBy,tab1,1) ){
        return 1;

      }
      sqlite3VdbeAddOp(v, OP_OpenTemp, tab1, 1);
      sqlite3VdbeAddOp(v, OP_KeyAsData, tab1, 1);


      /* Code the SELECTs to our left into temporary table "tab1".
      */
      rc = sqlite3Select(pParse, pPrior, SRT_Union, tab1, 0, 0, 0);
      if( rc ) return rc;



      /* Code the current SELECT into temporary table "tab2"
      */
      sqlite3VdbeAddOp(v, OP_OpenTemp, tab2, 1);
      sqlite3VdbeAddOp(v, OP_KeyAsData, tab2, 1);
      p->pPrior = 0;
      nLimit = p->nLimit;
      p->nLimit = -1;
      nOffset = p->nOffset;
      p->nOffset = 0;
      rc = sqlite3Select(pParse, p, SRT_Union, tab2, 0, 0, 0);
      p->pPrior = pPrior;
      p->nLimit = nLimit;
      p->nOffset = nOffset;
      if( rc ) return rc;



      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      if( eDest==SRT_Callback ){
        generateColumnNames(pParse, 0, p->pEList);
................................................................................
      sqlite3VdbeAddOp(v, OP_Rewind, tab1, iBreak);
      computeLimitRegisters(pParse, p);
      iStart = sqlite3VdbeAddOp(v, OP_FullKey, tab1, 0);
      sqlite3VdbeAddOp(v, OP_NotFound, tab2, iCont);
      multiSelectSortOrder(p, p->pOrderBy);
      rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
                             p->pOrderBy, -1, eDest, iParm, 
                             iCont, iBreak);
      if( rc ) return 1;



      sqlite3VdbeResolveLabel(v, iCont);
      sqlite3VdbeAddOp(v, OP_Next, tab1, iStart);
      sqlite3VdbeResolveLabel(v, iBreak);
      sqlite3VdbeAddOp(v, OP_Close, tab2, 0);
      sqlite3VdbeAddOp(v, OP_Close, tab1, 0);
      if( p->pOrderBy ){
        generateSortTail(p, v, p->pEList->nExpr, eDest, iParm);
................................................................................
      break;
    }
  }
  assert( p->pEList && pPrior->pEList );
  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
      " do not have the same number of result columns", selectOpName(p->op));
    return 1;

  }










  return 0;
}

/*
** Scan through the expression pExpr.  Replace every reference to
** a column in table number iTable with a copy of the iColumn-th
** entry in pEList.  (But leave references to the ROWID column 
** unchanged.)
................................................................................
    sqlite3VdbeAddOp(v, OP_Close, base+1, 0);
    sqlite3VdbeAddOp(v, OP_MoveTo, base, 0);
  }
  eList.nExpr = 1;
  memset(&eListItem, 0, sizeof(eListItem));
  eList.a = &eListItem;
  eList.a[0].pExpr = pExpr;
  selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, eDest, iParm, cont, cont);
  sqlite3VdbeResolveLabel(v, cont);
  sqlite3VdbeAddOp(v, OP_Close, base, 0);
  
  return 1;
}

/*
................................................................................
int sqlite3Select(
  Parse *pParse,         /* The parser context */
  Select *p,             /* The SELECT statement being coded. */
  int eDest,             /* How to dispose of the results */
  int iParm,             /* A parameter used by the eDest disposal method */
  Select *pParent,       /* Another SELECT for which this is a sub-query */
  int parentTab,         /* Index in pParent->pSrc of this query */
  int *pParentAgg        /* True if pParent uses aggregate functions */

){
  int i;
  WhereInfo *pWInfo;
  Vdbe *v;
  int isAgg = 0;         /* True for select lists like "count(*)" */
  ExprList *pEList;      /* List of columns to extract. */
  SrcList *pTabList;     /* List of tables to select from */
................................................................................

  if( sqlite3_malloc_failed || pParse->nErr || p==0 ) return 1;
  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;

  /* If there is are a sequence of queries, do the earlier ones first.
  */
  if( p->pPrior ){
    return multiSelect(pParse, p, eDest, iParm);
  }

  /* Make local copies of the parameters for this query.
  */
  pTabList = p->pSrc;
  pWhere = p->pWhere;
  pOrderBy = p->pOrderBy;
................................................................................

  /* Identify column names if we will be using them in a callback.  This
  ** step is skipped if the output is going to some other destination.
  */
  if( eDest==SRT_Callback ){
    generateColumnNames(pParse, pTabList, pEList);
  }
















  /* Generate code for all sub-queries in the FROM clause
  */
  for(i=0; i<pTabList->nSrc; i++){
    const char *zSavedAuthContext;
    int needRestoreContext;

................................................................................
      zSavedAuthContext = pParse->zAuthContext;
      pParse->zAuthContext = pTabList->a[i].zName;
      needRestoreContext = 1;
    }else{
      needRestoreContext = 0;
    }
    sqlite3Select(pParse, pTabList->a[i].pSelect, SRT_TempTable, 
                 pTabList->a[i].iCursor, p, i, &isAgg);
    if( needRestoreContext ){
      pParse->zAuthContext = zSavedAuthContext;
    }
    pTabList = p->pSrc;
    pWhere = p->pWhere;
    if( eDest!=SRT_Union && eDest!=SRT_Except && eDest!=SRT_Discard ){
      pOrderBy = p->pOrderBy;
................................................................................
  if( pWInfo==0 ) goto select_end;

  /* Use the standard inner loop if we are not dealing with
  ** aggregates
  */
  if( !isAgg ){
    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
                    iParm, pWInfo->iContinue, pWInfo->iBreak) ){
       goto select_end;
    }
  }

  /* If we are dealing with aggregates, then do the special aggregate
  ** processing.  
  */
................................................................................
    int startagg;
    startagg = sqlite3VdbeAddOp(v, OP_AggNext, 0, endagg);
    pParse->useAgg = 1;
    if( pHaving ){
      sqlite3ExprIfFalse(pParse, pHaving, startagg, 1);
    }
    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
                    iParm, startagg, endagg) ){
      goto select_end;
    }
    sqlite3VdbeAddOp(v, OP_Goto, 0, startagg);
    sqlite3VdbeResolveLabel(v, endagg);
    sqlite3VdbeAddOp(v, OP_Noop, 0, 0);
    pParse->useAgg = 0;
  }

**    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 SELECT statements in SQLite.
**
** $Id: select.c,v 1.167 2004/05/18 09:58:08 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.
................................................................................
  int srcTab,             /* Pull data from this table */
  int nColumn,            /* Number of columns in the source table */
  ExprList *pOrderBy,     /* If not NULL, sort results using this key */
  int distinct,           /* If >=0, make sure results are distinct */
  int eDest,              /* How to dispose of the results */
  int iParm,              /* An argument to the disposal method */
  int iContinue,          /* Jump here to continue with next row */
  int iBreak,             /* Jump here to break out of the inner loop */
  char *aff               /* affinity string if eDest is SRT_Union */
){
  Vdbe *v = pParse->pVdbe;
  int i;

  if( v==0 ) return 0;
  assert( pEList!=0 );

................................................................................

  switch( eDest ){
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
    case SRT_Union: {
      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);
      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
      sqlite3VdbeAddOp(v, OP_String, 0, 0);
      sqlite3VdbeAddOp(v, OP_PutStrKey, iParm, 0);
      break;
    }

    /* Store the result as data using a unique key.
    */
................................................................................
    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);
      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
      sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
      break;
    }

    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
................................................................................
      if( pOrderBy ){
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        char const *affStr;
        char aff = (iParm>>16)&0xFF;
        aff = sqlite3CompareAffinity(pEList->a[0].pExpr, aff);
        affStr = sqlite3AffinityString(aff);
        sqlite3VdbeOp3(v, OP_MakeKey, 1, 0, affStr, P3_STATIC);
        sqlite3VdbeAddOp(v, OP_String, 0, 0);
        sqlite3VdbeAddOp(v, OP_PutStrKey, (iParm&0x0000FFFF), 0);
      }
      sqlite3VdbeChangeP2(v, addr2, sqlite3VdbeCurrentAddr(v));
      break;
    }

................................................................................
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
      sqlite3VdbeAddOp(v, OP_Goto, 0, end1);
      break;
    }
    case SRT_Subroutine: {
      int i;
      sqlite3VdbeAddOp(v, OP_Integer, p->pEList->nExpr, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp(v, OP_Column, -1-i, i);
      }
      sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
      sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
      break;
    }
    default: {
      /* Do nothing */
      break;
    }
  }
................................................................................
    if( pE->dataType==SQLITE_SO_NUM ) continue;
    assert( pE->iColumn>=0 );
    if( pEList->nExpr>pE->iColumn ){
      pE->dataType = sqlite3ExprType(pEList->a[pE->iColumn].pExpr);
    }
  }
}

static void multiSelectAffinity(Select *p, char *zAff){
  int i;

  if( !p ) return;
  multiSelectAffinity(p->pPrior, zAff);

  for(i=0; i<p->pEList->nExpr; i++){
    if( zAff[i]=='\0' ){
      zAff[i] = sqlite3ExprAffinity(p->pEList->a[i].pExpr);
    }
  }
}

/*
** Compute the iLimit and iOffset fields of the SELECT based on the
** nLimit and nOffset fields.  nLimit and nOffset hold the integers
** that appear in the original SQL statement after the LIMIT and OFFSET
** keywords.  Or that hold -1 and 0 if those keywords are omitted.
** iLimit and iOffset are the integer memory register numbers for
................................................................................
** The arrows in the diagram above represent the Select.pPrior pointer.
** So if this routine is called with p equal to the t3 query, then
** pPrior will be the t2 query.  p->op will be TK_UNION in this case.
**
** Notice that because of the way SQLite parses compound SELECTs, the
** individual selects always group from left to right.
*/
static int multiSelect(
  Parse *pParse, 
  Select *p, 
  int eDest, 
  int iParm, 
  char *aff           /* If eDest is SRT_Union, the affinity string */
){
  int rc = SQLITE_OK;  /* Success code from a subroutine */
  Select *pPrior;     /* Another SELECT immediately to our left */
  Vdbe *v;            /* Generate code to this VDBE */
  char *affStr = 0;

  if( !aff ){
    int len;
    rc = fillInColumnList(pParse, p);
    if( rc!=SQLITE_OK ){
      goto multi_select_end;
    }
    len = p->pEList->nExpr+1;
    affStr = (char *)sqliteMalloc(p->pEList->nExpr+1);
    if( !affStr ){
      rc = SQLITE_NOMEM;
      goto multi_select_end;
    }
    memset(affStr, (int)SQLITE_AFF_NUMERIC, len-1);
    aff = affStr;
  }

  /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only
  ** the last SELECT in the series may have an ORDER BY or LIMIT.
  */
  if( p==0 || p->pPrior==0 ){
    rc = 1;
    goto multi_select_end;
  }
  pPrior = p->pPrior;
  if( pPrior->pOrderBy ){
    sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
      selectOpName(p->op));
    rc = 1;
    goto multi_select_end;
  }
  if( pPrior->nLimit>=0 || pPrior->nOffset>0 ){
    sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before",
      selectOpName(p->op));
    rc = 1;
    goto multi_select_end;
  }

  /* Make sure we have a valid query engine.  If not, create a new one.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ){
    rc = 1;
    goto multi_select_end;
  }

  /* Create the destination temporary table if necessary
  */
  if( eDest==SRT_TempTable ){
    assert( p->pEList );
    sqlite3VdbeAddOp(v, OP_OpenTemp, iParm, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, p->pEList->nExpr);
................................................................................
  /* Generate code for the left and right SELECT statements.
  */
  switch( p->op ){
    case TK_ALL: {
      if( p->pOrderBy==0 ){
        pPrior->nLimit = p->nLimit;
        pPrior->nOffset = p->nOffset;
        rc = sqlite3Select(pParse, pPrior, eDest, iParm, 0, 0, 0, aff);
        if( rc ){
          goto multi_select_end;
        }
        p->pPrior = 0;
        p->iLimit = pPrior->iLimit;
        p->iOffset = pPrior->iOffset;
        p->nLimit = -1;
        p->nOffset = 0;
        rc = sqlite3Select(pParse, p, eDest, iParm, 0, 0, 0, aff);
        p->pPrior = pPrior;
        if( rc ){
          goto multi_select_end;
        }
        break;
      }
      /* For UNION ALL ... ORDER BY fall through to the next case */
    }
    case TK_EXCEPT:
    case TK_UNION: {
      int unionTab;    /* Cursor number of the temporary table holding result */
................................................................................
      }else{
        /* We will need to create our own temporary table to hold the
        ** intermediate results.
        */
        unionTab = pParse->nTab++;
        if( p->pOrderBy 
        && matchOrderbyToColumn(pParse, p, p->pOrderBy, unionTab, 1) ){
          rc = 1;
          goto multi_select_end;
        }
        if( p->op!=TK_ALL ){
          sqlite3VdbeAddOp(v, OP_OpenTemp, unionTab, 1);
          sqlite3VdbeAddOp(v, OP_KeyAsData, unionTab, 1);
        }else{
          sqlite3VdbeAddOp(v, OP_OpenTemp, unionTab, 0);
        }
        assert( p->pEList );
      }

      /* Code the SELECT statements to our left
      */
      rc = sqlite3Select(pParse, pPrior, priorOp, unionTab, 0, 0, 0, aff);
      if( rc ){
        goto multi_select_end;
      }
      if( p->op==TK_ALL ){
        sqlite3VdbeAddOp(v, OP_SetNumColumns, unionTab, pPrior->pEList->nExpr);
      }

      /* Code the current SELECT statement
      */
      switch( p->op ){
         case TK_EXCEPT:  op = SRT_Except;   break;
         case TK_UNION:   op = SRT_Union;    break;
         case TK_ALL:     op = SRT_Table;    break;
................................................................................
      p->pPrior = 0;
      pOrderBy = p->pOrderBy;
      p->pOrderBy = 0;
      nLimit = p->nLimit;
      p->nLimit = -1;
      nOffset = p->nOffset;
      p->nOffset = 0;
      rc = sqlite3Select(pParse, p, op, unionTab, 0, 0, 0, aff);
      p->pPrior = pPrior;
      p->pOrderBy = pOrderBy;
      p->nLimit = nLimit;
      p->nOffset = nOffset;
      if( rc ){
        goto multi_select_end;
      }


      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */      
      if( eDest!=priorOp || unionTab!=iParm ){
        int iCont, iBreak, iStart;
        assert( p->pEList );
................................................................................
        iCont = sqlite3VdbeMakeLabel(v);
        sqlite3VdbeAddOp(v, OP_Rewind, unionTab, iBreak);
        computeLimitRegisters(pParse, p);
        iStart = sqlite3VdbeCurrentAddr(v);
        multiSelectSortOrder(p, p->pOrderBy);
        rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
                             p->pOrderBy, -1, eDest, iParm, 
                             iCont, iBreak, 0);
        if( rc ){
          rc = 1;
          goto multi_select_end;
        }
        sqlite3VdbeResolveLabel(v, iCont);
        sqlite3VdbeAddOp(v, OP_Next, unionTab, iStart);
        sqlite3VdbeResolveLabel(v, iBreak);
        sqlite3VdbeAddOp(v, OP_Close, unionTab, 0);
        if( p->pOrderBy ){
          generateSortTail(p, v, p->pEList->nExpr, eDest, iParm);
        }
................................................................................
      /* INTERSECT is different from the others since it requires
      ** two temporary tables.  Hence it has its own case.  Begin
      ** by allocating the tables we will need.
      */
      tab1 = pParse->nTab++;
      tab2 = pParse->nTab++;
      if( p->pOrderBy && matchOrderbyToColumn(pParse,p,p->pOrderBy,tab1,1) ){
        rc = 1;
        goto multi_select_end;
      }
      sqlite3VdbeAddOp(v, OP_OpenTemp, tab1, 1);
      sqlite3VdbeAddOp(v, OP_KeyAsData, tab1, 1);
      assert( p->pEList );

      /* Code the SELECTs to our left into temporary table "tab1".
      */
      rc = sqlite3Select(pParse, pPrior, SRT_Union, tab1, 0, 0, 0, aff);
      if( rc ){
        goto multi_select_end;
      }

      /* Code the current SELECT into temporary table "tab2"
      */
      sqlite3VdbeAddOp(v, OP_OpenTemp, tab2, 1);
      sqlite3VdbeAddOp(v, OP_KeyAsData, tab2, 1);
      p->pPrior = 0;
      nLimit = p->nLimit;
      p->nLimit = -1;
      nOffset = p->nOffset;
      p->nOffset = 0;
      rc = sqlite3Select(pParse, p, SRT_Union, tab2, 0, 0, 0, aff);
      p->pPrior = pPrior;
      p->nLimit = nLimit;
      p->nOffset = nOffset;
      if( rc ){
        goto multi_select_end;
      }

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      if( eDest==SRT_Callback ){
        generateColumnNames(pParse, 0, p->pEList);
................................................................................
      sqlite3VdbeAddOp(v, OP_Rewind, tab1, iBreak);
      computeLimitRegisters(pParse, p);
      iStart = sqlite3VdbeAddOp(v, OP_FullKey, tab1, 0);
      sqlite3VdbeAddOp(v, OP_NotFound, tab2, iCont);
      multiSelectSortOrder(p, p->pOrderBy);
      rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
                             p->pOrderBy, -1, eDest, iParm, 
                             iCont, iBreak, 0);
      if( rc ){
        rc = 1;
        goto multi_select_end;
      }
      sqlite3VdbeResolveLabel(v, iCont);
      sqlite3VdbeAddOp(v, OP_Next, tab1, iStart);
      sqlite3VdbeResolveLabel(v, iBreak);
      sqlite3VdbeAddOp(v, OP_Close, tab2, 0);
      sqlite3VdbeAddOp(v, OP_Close, tab1, 0);
      if( p->pOrderBy ){
        generateSortTail(p, v, p->pEList->nExpr, eDest, iParm);
................................................................................
      break;
    }
  }
  assert( p->pEList && pPrior->pEList );
  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
      " do not have the same number of result columns", selectOpName(p->op));
    rc = 1;
    goto multi_select_end;
  }

multi_select_end:
  if( affStr ){
    if( rc!=SQLITE_OK ){
      sqliteFree(affStr);
    }else{
      multiSelectAffinity(p, affStr);
      sqlite3VdbeOp3(v, OP_Noop, 0, 0, affStr, P3_DYNAMIC);
    }
  }
  return rc;
}

/*
** Scan through the expression pExpr.  Replace every reference to
** a column in table number iTable with a copy of the iColumn-th
** entry in pEList.  (But leave references to the ROWID column 
** unchanged.)
................................................................................
    sqlite3VdbeAddOp(v, OP_Close, base+1, 0);
    sqlite3VdbeAddOp(v, OP_MoveTo, base, 0);
  }
  eList.nExpr = 1;
  memset(&eListItem, 0, sizeof(eListItem));
  eList.a = &eListItem;
  eList.a[0].pExpr = pExpr;
  selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, eDest, iParm, cont, cont, 0);
  sqlite3VdbeResolveLabel(v, cont);
  sqlite3VdbeAddOp(v, OP_Close, base, 0);
  
  return 1;
}

/*
................................................................................
int sqlite3Select(
  Parse *pParse,         /* The parser context */
  Select *p,             /* The SELECT statement being coded. */
  int eDest,             /* How to dispose of the results */
  int iParm,             /* A parameter used by the eDest disposal method */
  Select *pParent,       /* Another SELECT for which this is a sub-query */
  int parentTab,         /* Index in pParent->pSrc of this query */
  int *pParentAgg,       /* True if pParent uses aggregate functions */
  char *aff              /* If eDest is SRT_Union, the affinity string */
){
  int i;
  WhereInfo *pWInfo;
  Vdbe *v;
  int isAgg = 0;         /* True for select lists like "count(*)" */
  ExprList *pEList;      /* List of columns to extract. */
  SrcList *pTabList;     /* List of tables to select from */
................................................................................

  if( sqlite3_malloc_failed || pParse->nErr || p==0 ) return 1;
  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;

  /* If there is are a sequence of queries, do the earlier ones first.
  */
  if( p->pPrior ){
    return multiSelect(pParse, p, eDest, iParm, aff);
  }

  /* Make local copies of the parameters for this query.
  */
  pTabList = p->pSrc;
  pWhere = p->pWhere;
  pOrderBy = p->pOrderBy;
................................................................................

  /* Identify column names if we will be using them in a callback.  This
  ** step is skipped if the output is going to some other destination.
  */
  if( eDest==SRT_Callback ){
    generateColumnNames(pParse, pTabList, pEList);
  }

  /* If the destination is SRT_Union, then set the number of columns in
  ** the records that will be inserted into the temporary table. The caller
  ** couldn't do this, in case the select statement is of the form 
  ** "SELECT * FROM ....". 
  **
  ** We need to do this before we start inserting records into the 
  ** temporary table (which has had OP_KeyAsData executed on it), because
  ** it is required by the key comparison function. So do it now, even
  ** though this means that OP_SetNumColumns may be executed on the same
  ** cursor more than once.
  */
  if( eDest==SRT_Union ){
    sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, pEList->nExpr);
  }

  /* Generate code for all sub-queries in the FROM clause
  */
  for(i=0; i<pTabList->nSrc; i++){
    const char *zSavedAuthContext;
    int needRestoreContext;

................................................................................
      zSavedAuthContext = pParse->zAuthContext;
      pParse->zAuthContext = pTabList->a[i].zName;
      needRestoreContext = 1;
    }else{
      needRestoreContext = 0;
    }
    sqlite3Select(pParse, pTabList->a[i].pSelect, SRT_TempTable, 
                 pTabList->a[i].iCursor, p, i, &isAgg, 0);
    if( needRestoreContext ){
      pParse->zAuthContext = zSavedAuthContext;
    }
    pTabList = p->pSrc;
    pWhere = p->pWhere;
    if( eDest!=SRT_Union && eDest!=SRT_Except && eDest!=SRT_Discard ){
      pOrderBy = p->pOrderBy;
................................................................................
  if( pWInfo==0 ) goto select_end;

  /* Use the standard inner loop if we are not dealing with
  ** aggregates
  */
  if( !isAgg ){
    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
                    iParm, pWInfo->iContinue, pWInfo->iBreak, aff) ){
       goto select_end;
    }
  }

  /* If we are dealing with aggregates, then do the special aggregate
  ** processing.  
  */
................................................................................
    int startagg;
    startagg = sqlite3VdbeAddOp(v, OP_AggNext, 0, endagg);
    pParse->useAgg = 1;
    if( pHaving ){
      sqlite3ExprIfFalse(pParse, pHaving, startagg, 1);
    }
    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
                    iParm, startagg, endagg, aff) ){
      goto select_end;
    }
    sqlite3VdbeAddOp(v, OP_Goto, 0, startagg);
    sqlite3VdbeResolveLabel(v, endagg);
    sqlite3VdbeAddOp(v, OP_Noop, 0, 0);
    pParse->useAgg = 0;
  }

**    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 1.75 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
**
**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
................................................................................

  /* If we are trying to update a view, construct that view into
  ** a temporary table.
  */
  if( isView ){
    Select *pView;
    pView = sqlite3SelectDup(pTab->pSelect);
    sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0);
    sqlite3SelectDelete(pView);
  }

  /* Begin the database scan
  */
  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 1, 0);
  if( pWInfo==0 ) goto update_cleanup;
................................................................................
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
  }

  if( row_triggers_exist ){
    /* Create pseudo-tables for NEW and OLD
    */
    sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);

    sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);


    /* The top of the update loop for when there are triggers.
    */
    sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);
    addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);

**    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 1.76 2004/05/18 09:58:08 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
**
**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;
................................................................................

  /* If we are trying to update a view, construct that view into
  ** a temporary table.
  */
  if( isView ){
    Select *pView;
    pView = sqlite3SelectDup(pTab->pSelect);
    sqlite3Select(pParse, pView, SRT_TempTable, iCur, 0, 0, 0, 0);
    sqlite3SelectDelete(pView);
  }

  /* Begin the database scan
  */
  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 1, 0);
  if( pWInfo==0 ) goto update_cleanup;
................................................................................
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
  }

  if( row_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.
    */
    sqlite3VdbeAddOp(v, OP_ListRewind, 0, 0);
    addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);

**
** 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 1.297 2004/05/18 01:23:38 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
................................................................................
      /* Affinity NONE. Do nothing. */
      break;

    default:
      assert(0);
  }
}




















































#ifdef VDBE_PROFILE
/*
** The following routine only works on pentium-class processors.
** It uses the RDTSC opcode to read cycle count value out of the
** processor and returns that value.  This can be used for high-res
** profiling.
................................................................................
** If the KeyAsData opcode has previously executed on this cursor, then the
** field might be extracted from the key rather than the data.
**
** If P1 is negative, then the record is stored on the stack rather than in
** a table.  For P1==-1, the top of the stack is used.  For P1==-2, the
** next on the stack is used.  And so forth.  The value pushed is always
** just a pointer into the record which is stored further down on the
** stack.  The column value is not copied.

*/
case OP_Column: {
  int payloadSize;   /* Number of bytes in the record */
  int i = pOp->p1;
  int p2 = pOp->p2;  /* column number to retrieve */
  Cursor *pC = 0;
  char *zRec;        /* Pointer to record-data from stack or pseudo-table. */
  BtCursor *pCrsr;

  char *zData;       
  int freeZdata = 0; /* zData requires sqliteFree() */

  u64 nField;        /* number of fields in the record */

  int len;           /* The length of the serialized data for the column */
  int offset = 0;
  int nn;





  assert( i<p->nCursor );
  pTos++;

  /* This block sets the variable payloadSize, and if the data is coming
  ** from the stack or from a pseudo-table zRec. If the data is coming
  ** from a real cursor, then zRec is left as NULL.



  */
  if( i<0 ){





    assert( &pTos[i]>=p->aStack );
    assert( pTos[i].flags & MEM_Str );







    zRec = pTos[i].z;
    payloadSize = pTos[i].n;
    pC->cacheValid = 0;
    assert(!"broken for now");





















  }else if( (pC = p->apCsr[i])->pCursor!=0 ){
    sqlite3VdbeCursorMoveto(pC);
    zRec = 0;
    pCrsr = pC->pCursor;
    if( pC->nullRow ){
      payloadSize = 0;
    }else if( pC->cacheValid ){
      payloadSize = pC->payloadSize;
................................................................................
  assert( !pC || pC->nField>0 );
  assert( p2<pC->nField );
  nField = pC->nField;

  /* Read and parse the table header.  Store the results of the parse
  ** into the record header cache fields of the cursor.
  */
  if( !pC->cacheValid ){
    pC->payloadSize = payloadSize;
#if 0
    if( zRec ){
      zData = zRec;
    }else{
      /* We can assume that 10 bytes (maximum length of a varint) fits
      ** on the main page in all cases.
      */
      int n = 10;
      if( payloadSize<10 ) n = payloadSize;
      if( pC->keyAsData ){
        zData = (char *)sqlite3BtreeKeyFetch(pCrsr, n);
      }else{
        zData = (char *)sqlite3BtreeDataFetch(pCrsr, n);
      }
      assert( zData );
    }
    {
      u64 x;
      offset = sqlite3GetVarint(zData, &x);
      assert( x==nField );
    }
#endif

    if( !pC->aType ){
      pC->aType = sqliteMallocRaw( nField*sizeof(pC->aType[0]) );
      if( pC->aType==0 ){
        goto no_mem;
      }
    }

    if( !zRec ){
      /* If the record is stored in a table, see if enough of it is on
      ** the main page to use sqlite3BtreeDataFetch() to get the data
      ** containing the nField serial types (varints). This will almost
      ** always work, but if it doesn't sqliteMalloc() space and use
      ** sqlite3BtreeData().
      **
      ** Estimate the maximum space required by the nField varints by
      ** assuming the maximum space for each is the length required to store:
      **
      **     (<record length> * 2) + 13
      **
      ** This is the serial-type for a text object as long as the record
      ** itself. In all cases the length required to store this is three
      ** bytes or less. 
      */
      int max_space = sqlite3VarintLen((((u64)payloadSize)<<1)+13)*nField;
      max_space += offset;
      if( max_space>payloadSize ){
        max_space = payloadSize;
      }

      if( pC->keyAsData ){
        zData = (char *)sqlite3BtreeKeyFetch(pCrsr, max_space);
      }else{
        zData = (char *)sqlite3BtreeDataFetch(pCrsr, max_space);
      }
      if( !zData ){
        /* This code will run very infrequently (e.g. tables with several
        ** hundred columns).
        */
        zData = (char *)sqliteMallocRaw(max_space);
        if( !zData ){
          goto no_mem;
        }
        if( pC->keyAsData ){
          rc = sqlite3BtreeKey(pCrsr, 0, max_space, zData);
        }else{
          rc = sqlite3BtreeData(pCrsr, 0, max_space, zData);
        }
        if( rc!=SQLITE_OK ){
          sqliteFree(zData);
          goto abort_due_to_error;
        }
        freeZdata = 1;
      }
    }

    /* Read all the serial types for the record.  At the end of this block
    ** variable offset is set to the offset to the start of Data0 in the record.
    */
    for(nn=0; nn<nField; nn++){
      offset += sqlite3GetVarint(&zData[offset], &pC->aType[nn]);
    }
    if( freeZdata ){
      freeZdata = 0;
      sqliteFree(zData);
    }
    pC->nHeader = offset;
    pC->cacheValid = 1;



  }

  /* Compute the offset from the beginning of the record to the beginning
  ** of the data.  And get the length of the data.
  */
  offset = pC->nHeader;
  for(nn=0; nn<p2; nn++){
    offset += sqlite3VdbeSerialTypeLen(pC->aType[nn]);
  }
  len = sqlite3VdbeSerialTypeLen(pC->aType[p2]);

  if( !zRec ){
    /* If the record is stored in a table, see if enough of it
    ** is on the main page to read our column using
    ** sqlite3BtreeDataFetch(). If not sqliteMalloc() space and read data
    ** with sqlite3BtreeData().
    */
    if( pC->keyAsData ){
      zData = (char *)sqlite3BtreeKeyFetch(pCrsr, offset+len);

    }else{
      zData = (char *)sqlite3BtreeDataFetch(pCrsr, offset+len);
    }
    if( !zData ){
      zData = (char *)sqliteMallocRaw(len);
      if( !zData ){
        goto no_mem;
      }
      if( pC->keyAsData ){

        rc = sqlite3BtreeKey(pCrsr, offset, len, zData);
      }else{
        rc = sqlite3BtreeData(pCrsr, offset, len, zData);
      }
      if( rc!=SQLITE_OK ){
        sqliteFree( zData );
        goto abort_due_to_error;
      }
      freeZdata = 1;
      offset = 0;
    }
  }

  /* Deserialize the value directly into the top of the stack */
  sqlite3VdbeSerialGet(&zData[offset], pC->aType[p2], pTos);

  if( freeZdata ){
    sqliteFree(zData);
  }

  break;
}

/* Opcode MakeRecord P1 * P3
**
** This opcode (not yet in use) is a replacement for the current
** OP_MakeRecord that supports the SQLite3 manifest typing feature.
................................................................................
  Mem *pData0 = &pTos[1-nField];
  assert( pData0>=p->aStack );
  zAffinity = pOp->p3;

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */
  // nBytes = sqlite3VarintLen(nField);
  for(pRec=pData0; pRec<=pTos; pRec++){
    u64 serial_type;
    if( zAffinity ){
      applyAffinity(pRec, zAffinity[pRec-pData0]);
    }
    serial_type = sqlite3VdbeSerialType(pRec);
    nBytes += sqlite3VdbeSerialTypeLen(serial_type);
................................................................................
  zNewRecord = sqliteMallocRaw(nBytes);
  if( !zNewRecord ){
    goto no_mem;
  }

  /* Write the record */
  zCsr = zNewRecord;
  // zCsr += sqlite3PutVarint(zCsr, nField);             /* number of fields */
  for(pRec=pData0; pRec<=pTos; pRec++){
    u64 serial_type = sqlite3VdbeSerialType(pRec);
    zCsr += sqlite3PutVarint(zCsr, serial_type);      /* serial type */
  }
  for(pRec=pData0; pRec<=pTos; pRec++){
    zCsr += sqlite3VdbeSerialPut(zCsr, pRec);  /* serial data */
  }
................................................................................

  break;
}

/* Opcode: MakeKey P1 P2 P3
**
** Convert the top P1 entries of the stack into a single entry suitable
** for use as the key in an index. If P2 is not zero, then the original 
** entries are popped off the stack. If P2 is zero, the original entries
** remain on the stack.
**
** P3 is interpreted in the same way as for MakeIdxKey.
*/
/* Opcode: MakeIdxKey P1 P2 P3
**
** Convert the top P1 entries of the stack into a single entry suitable
** for use as the key in an index.  In addition, take one additional integer
................................................................................

/* Opcode: KeyAsData P1 P2 *
**
** Turn the key-as-data mode for cursor P1 either on (if P2==1) or
** off (if P2==0).  In key-as-data mode, the OP_Column opcode pulls
** data off of the key rather than the data.  This is used for
** processing compound selects.




*/
case OP_KeyAsData: {
  int i = pOp->p1;
  assert( i>=0 && i<p->nCursor );
  p->apCsr[i]->keyAsData = pOp->p2;

  break;
}

/* Opcode: RowData P1 * *
**
** Push onto the stack the complete row data for cursor P1.
** There is no interpretation of the data.  It is just copied

**
** 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 1.298 2004/05/18 09:58:08 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
................................................................................
      /* Affinity NONE. Do nothing. */
      break;

    default:
      assert(0);
  }
}

static int getBtreeMem(
  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
  int offset,       /* Offset from the start of data to return bytes from. */
  int amt,          /* Number of bytes to return. */
  int key,          /* If true, retrieve from the btree key, not data. */
  Mem *pMem         /* OUT: Return data in this Mem structure. */
){
  char *zData;

  if( key ){
    zData = (char *)sqlite3BtreeKeyFetch(pCur, offset+amt);
  }else{
    zData = (char *)sqlite3BtreeDataFetch(pCur, offset+amt);
  }

  if( zData ){
    pMem->z = &zData[offset];
    pMem->n = amt;
    pMem->flags = MEM_Blob|MEM_Ephem;
  }else{
    int rc;
    if( amt>NBFS ){
      zData = (char *)sqliteMallocRaw(amt);
      if( !zData ){
        return SQLITE_NOMEM;
      }
      pMem->flags = MEM_Blob|MEM_Dyn;
    }else{
      zData = &(pMem->zShort[0]);
      pMem->flags = MEM_Blob|MEM_Short;
    }
    pMem->z = zData;

    if( key ){
      rc = sqlite3BtreeKey(pCur, offset, amt, zData);
    }else{
      rc = sqlite3BtreeData(pCur, offset, amt, zData);
    }

    if( rc!=SQLITE_OK ){
      if( amt>NBFS ){
        sqliteFree(zData);
      }
      return rc;
    }
  }

  return SQLITE_OK;
}


#ifdef VDBE_PROFILE
/*
** The following routine only works on pentium-class processors.
** It uses the RDTSC opcode to read cycle count value out of the
** processor and returns that value.  This can be used for high-res
** profiling.
................................................................................
** If the KeyAsData opcode has previously executed on this cursor, then the
** field might be extracted from the key rather than the data.
**
** If P1 is negative, then the record is stored on the stack rather than in
** a table.  For P1==-1, the top of the stack is used.  For P1==-2, the
** next on the stack is used.  And so forth.  The value pushed is always
** just a pointer into the record which is stored further down on the
** stack.  The column value is not copied. The number of columns in the
** record is stored on the stack just above the record itself.
*/
case OP_Column: {
  int payloadSize;   /* Number of bytes in the record */
  int i = pOp->p1;
  int p2 = pOp->p2;  /* column number to retrieve */
  Cursor *pC = 0;
  char *zRec;        /* Pointer to record-data from stack or pseudo-table. */
  BtCursor *pCrsr;




  u64 nField;        /* number of fields in the record */

  int len;           /* The length of the serialized data for the column */
  int offset = 0;
  int nn;

  char *zData;       
  Mem zMem;
  zMem.flags = 0;

  assert( i<p->nCursor );
  pTos++;




  /* If the record is coming from the stack, not from a cursor, then there
  ** is nowhere to cache the record header infomation. This simplifies
  ** things greatly, so deal with this case seperately.
  */
  if( i<0 ){
    char *zRec;     /* Pointer to record data from the stack. */
    int off = 0;    /* Offset in zRec to start of the columns data. */
    int off2 = 0;   /* Offset in zRec to the next serial type to read */
    u64 colType;    /* The serial type of the value being read. */

    assert( &pTos[i-1]>=p->aStack );
    assert( pTos[i].flags & MEM_Str );
    assert( pTos[i-1].flags & MEM_Int );

    if( pTos[i].n==0 ){
      pTos->flags = MEM_Null;
      break;
    }

    zRec = pTos[i].z;
    nField = pTos[i-1].i;


     
    for( nn=0; nn<nField; nn++ ){
      u64 v;
      off2 += sqlite3GetVarint(&zRec[off2], &v);
      if( nn==p2 ){
        colType = v;
      }else if( nn<p2 ){
        off += sqlite3VdbeSerialTypeLen(v);
      }
    }
    off += off2;
    
    sqlite3VdbeSerialGet(&zRec[off], colType, pTos);
    break;
  }


  /* This block sets the variable payloadSize, and if the data is coming
  ** from the stack or from a pseudo-table zRec. If the data is coming
  ** from a real cursor, then zRec is left as NULL.
  */
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    sqlite3VdbeCursorMoveto(pC);
    zRec = 0;
    pCrsr = pC->pCursor;
    if( pC->nullRow ){
      payloadSize = 0;
    }else if( pC->cacheValid ){
      payloadSize = pC->payloadSize;
................................................................................
  assert( !pC || pC->nField>0 );
  assert( p2<pC->nField );
  nField = pC->nField;

  /* Read and parse the table header.  Store the results of the parse
  ** into the record header cache fields of the cursor.
  */
  if( !pC || !pC->cacheValid ){
    pC->payloadSize = payloadSize;























    if( !pC->aType ){
      pC->aType = sqliteMallocRaw( nField*sizeof(pC->aType[0]) );
      if( pC->aType==0 ){
        goto no_mem;
      }
    }

    if( zRec ){
      zData = zRec;
    }else{




      /* Estimate the maximum space required by the nField varints by
      ** assuming the maximum space for each is the length required to store:
      **
      **     (<record length> * 2) + 13
      **
      ** This is the serial-type for a text object as long as the record
      ** itself. In almost all cases the length required to store this is
      ** three bytes or less. 
      */
      int max_space = sqlite3VarintLen((((u64)payloadSize)<<1)+13)*nField;

      if( max_space>payloadSize ){
        max_space = payloadSize;
      }















      rc = getBtreeMem(pCrsr, 0, max_space, pC->keyAsData, &zMem);



      if( rc!=SQLITE_OK ){

        goto abort_due_to_error;
      }
      zData = zMem.z;

    }

    /* Read all the serial types for the record.  At the end of this block
    ** variable offset is set to the offset to the start of Data0 in the record.
    */
    for(nn=0; nn<nField; nn++){
      offset += sqlite3GetVarint(&zData[offset], &pC->aType[nn]);
    }




    pC->nHeader = offset;
    pC->cacheValid = 1;

    Release(&zMem);
    zMem.flags = 0;
  }

  /* Compute the offset from the beginning of the record to the beginning
  ** of the data.  And get the length of the data.
  */
  offset = pC->nHeader;
  for(nn=0; nn<p2; nn++){
    offset += sqlite3VdbeSerialTypeLen(pC->aType[nn]);
  }


  if( zRec ){







    zData = &zRec[offset];
  }else{








    len = sqlite3VdbeSerialTypeLen(pC->aType[p2]);
    getBtreeMem(pCrsr, offset, len, pC->keyAsData, &zMem);







    zData = zMem.z;

  }



  sqlite3VdbeSerialGet(zData, pC->aType[p2], pTos);




  Release(&zMem);
  break;
}

/* Opcode MakeRecord P1 * P3
**
** This opcode (not yet in use) is a replacement for the current
** OP_MakeRecord that supports the SQLite3 manifest typing feature.
................................................................................
  Mem *pData0 = &pTos[1-nField];
  assert( pData0>=p->aStack );
  zAffinity = pOp->p3;

  /* Loop through the elements that will make up the record to figure
  ** out how much space is required for the new record.
  */

  for(pRec=pData0; pRec<=pTos; pRec++){
    u64 serial_type;
    if( zAffinity ){
      applyAffinity(pRec, zAffinity[pRec-pData0]);
    }
    serial_type = sqlite3VdbeSerialType(pRec);
    nBytes += sqlite3VdbeSerialTypeLen(serial_type);
................................................................................
  zNewRecord = sqliteMallocRaw(nBytes);
  if( !zNewRecord ){
    goto no_mem;
  }

  /* Write the record */
  zCsr = zNewRecord;

  for(pRec=pData0; pRec<=pTos; pRec++){
    u64 serial_type = sqlite3VdbeSerialType(pRec);
    zCsr += sqlite3PutVarint(zCsr, serial_type);      /* serial type */
  }
  for(pRec=pData0; pRec<=pTos; pRec++){
    zCsr += sqlite3VdbeSerialPut(zCsr, pRec);  /* serial data */
  }
................................................................................

  break;
}

/* Opcode: MakeKey P1 P2 P3
**
** Convert the top P1 entries of the stack into a single entry suitable
** for use as the key in an index. If P2 is zero, then the original 
** entries are popped off the stack. If P2 is not zero, the original 
** entries remain on the stack.
**
** P3 is interpreted in the same way as for MakeIdxKey.
*/
/* Opcode: MakeIdxKey P1 P2 P3
**
** Convert the top P1 entries of the stack into a single entry suitable
** for use as the key in an index.  In addition, take one additional integer
................................................................................

/* Opcode: KeyAsData P1 P2 *
**
** Turn the key-as-data mode for cursor P1 either on (if P2==1) or
** off (if P2==0).  In key-as-data mode, the OP_Column opcode pulls
** data off of the key rather than the data.  This is used for
** processing compound selects.
**
** This opcode also instructs the cursor that the keys used will be
** serialized in the record format usually used for table data, not
** the usual index key format.
*/
case OP_KeyAsData: {
  int i = pOp->p1;
  assert( i>=0 && i<p->nCursor );
  p->apCsr[i]->keyAsData = pOp->p2;
  sqlite3BtreeSetCompare(p->apCsr[i]->pCursor, sqlite3VdbeRowCompare, p->apCsr[i]);
  break;
}

/* Opcode: RowData P1 * *
**
** Push onto the stack the complete row data for cursor P1.
** There is no interpretation of the data.  It is just copied

    }
  }
  while( j>0 && isspace(z[j-1]) ){ j--; }
  z[j] = 0;
}

/*
** Search for the current program for the given opcode and P2
** value.  Return the address plus 1 if found and 0 if not found.

*/
int sqlite3VdbeFindOp(Vdbe *p, int op, int p2){
  int i;
  assert( p->magic==VDBE_MAGIC_INIT );
  for(i=0; i<p->nOp; i++){
    if( p->aOp[i].opcode==op && p->aOp[i].p2==p2 ) return i+1;
  }
  return 0;
}

/*
** Return the opcode for a given address.
................................................................................

/*
** This function compares the two table row records specified by 
** {nKey1, pKey1} and {nKey2, pKey2}, returning a negative, zero
** or positive integer if {nKey1, pKey1} is less than, equal to or 
** greater than {nKey2, pKey2}.
**
** This function is pretty inefficient and will probably be replace
** by something else in the near future. It is currently required
** by compound SELECT operators. 
*/
int sqlite3VdbeRowCompare(
  void *userData,
  int nKey1, const void *pKey1, 
  int nKey2, const void *pKey2
){

  int offset1 = 0;
  int offset2 = 0;



  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  const unsigned char *aKey2 = (const unsigned char *)pKey2;

  assert( userData==0 );










































}
  

/*
** pCur points at an index entry. Read the rowid (varint occuring at
** the end of the entry and store it in *rowid. Return SQLITE_OK if
** everything works, or an error code otherwise.

    }
  }
  while( j>0 && isspace(z[j-1]) ){ j--; }
  z[j] = 0;
}

/*
** Search the current program starting at instruction addr for the given
** opcode and P2 value.  Return the address plus 1 if found and 0 if not
** found.
*/
int sqlite3VdbeFindOp(Vdbe *p, int addr, int op, int p2){
  int i;
  assert( p->magic==VDBE_MAGIC_INIT );
  for(i=addr; i<p->nOp; i++){
    if( p->aOp[i].opcode==op && p->aOp[i].p2==p2 ) return i+1;
  }
  return 0;
}

/*
** Return the opcode for a given address.
................................................................................

/*
** This function compares the two table row records specified by 
** {nKey1, pKey1} and {nKey2, pKey2}, returning a negative, zero
** or positive integer if {nKey1, pKey1} is less than, equal to or 
** greater than {nKey2, pKey2}.
**
** This function is pretty inefficient and will probably be replaced
** by something else in the near future. It is currently required
** by compound SELECT operators. 
*/
int sqlite3VdbeRowCompare(
  void *userData,
  int nKey1, const void *pKey1, 
  int nKey2, const void *pKey2
){
  Cursor *pC = (Cursor *)userData;
  int offset1 = 0;
  int offset2 = 0;
  int toffset1 = 0;
  int toffset2 = 0;
  int i;
  const unsigned char *aKey1 = (const unsigned char *)pKey1;
  const unsigned char *aKey2 = (const unsigned char *)pKey2;

  assert( pC );
  assert( pC->nField>0 );

  for( i=0; i<pC->nField; i++ ){
    u64 dummy;
    offset1 += sqlite3GetVarint(&aKey1[offset1], &dummy);
    offset2 += sqlite3GetVarint(&aKey1[offset1], &dummy);
  }

  for( i=0; i<pC->nField; i++ ){
    Mem mem1;
    Mem mem2;
    u64 serial_type1;
    u64 serial_type2;
    int rc;

    /* Read the serial types for the next element in each key. */
    toffset1 += sqlite3GetVarint(&aKey1[toffset1], &serial_type1);
    toffset2 += sqlite3GetVarint(&aKey2[toffset2], &serial_type2);

    assert( serial_type1 && serial_type2 );

    /* Assert that there is enough space left in each key for the blob of
    ** data to go with the serial type just read. This assert may fail if
    ** the file is corrupted.  Then read the value from each key into mem1
    ** and mem2 respectively.
    */
    offset1 += sqlite3VdbeSerialGet(&aKey1[offset1], serial_type1, &mem1);
    offset2 += sqlite3VdbeSerialGet(&aKey2[offset2], serial_type2, &mem2);

    rc = sqlite3MemCompare(&mem1, &mem2);
    if( mem1.flags&MEM_Dyn ){
      sqliteFree(mem1.z);
    }
    if( mem2.flags&MEM_Dyn ){
      sqliteFree(mem2.z);
    }
    if( rc!=0 ){
      return rc;
    }
  }

  return 0;
}
  

/*
** pCur points at an index entry. Read the rowid (varint occuring at
** the end of the entry and store it in *rowid. Return SQLITE_OK if
** everything works, or an error code otherwise.