SQLite

/*
** 2005 July 8
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.38 2008/01/12 12:48:08 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.

  int iDb,                /* The database we are looking in */
  int iStatCur,           /* Open the sqlite_stat1 table on this cursor */
  const char *zWhere      /* Delete entries associated with this table */
){
  sqlite3 *db = pParse->db;
  Db *pDb;
  int iRootPage;
  int createStat1 = 0;
  Table *pStat;
  Vdbe *v = sqlite3GetVdbe(pParse);

  if( v==0 ) return;
  assert( sqlite3BtreeHoldsAllMutexes(db) );
  assert( sqlite3VdbeDb(v)==db );
  pDb = &db->aDb[iDb];
  if( (pStat = sqlite3FindTable(db, "sqlite_stat1", pDb->zName))==0 ){
    /* The sqlite_stat1 tables does not exist.  Create it.  
    ** Note that a side-effect of the CREATE TABLE statement is to leave
    ** the rootpage of the new table in register pParse->regRoot.  This is
    ** important because the OpenWrite opcode below will be needing it. */
    sqlite3NestedParse(pParse,
      "CREATE TABLE %Q.sqlite_stat1(tbl,idx,stat)",
      pDb->zName
    );
    iRootPage = pParse->regRoot;
    createStat1 = 1;  /* Cause rootpage to be taken from top of stack */
  }else if( zWhere ){
    /* The sqlite_stat1 table exists.  Delete all entries associated with
    ** the table zWhere. */
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q.sqlite_stat1 WHERE tbl=%Q",
       pDb->zName, zWhere
    );
    iRootPage = pStat->tnum;
  }else{
    /* The sqlite_stat1 table already exists.  Delete all rows. */
    iRootPage = pStat->tnum;
    sqlite3VdbeAddOp2(v, OP_Clear, pStat->tnum, iDb);
  }

  /* Open the sqlite_stat1 table for writing. Unless it was created
  ** by this vdbe program, lock it for writing at the shared-cache level. 
  ** If this vdbe did create the sqlite_stat1 table, then it must have 
  ** already obtained a schema-lock, making the write-lock redundant.
  */
  if( !createStat1 ){
    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
  }
  sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur, iRootPage, iDb);

  sqlite3VdbeChangeP5(v, createStat1);

  sqlite3VdbeAddOp2(v, OP_SetNumColumns, iStatCur, 3);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.464 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.

  ** and allocate the record number for the table entry now.  Before any
  ** PRIMARY KEY or UNIQUE keywords are parsed.  Those keywords will cause
  ** indices to be created and the table record must come before the 
  ** indices.  Hence, the record number for the table must be allocated
  ** now.
  */
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int j1;
    int fileFormat;
    int reg1, reg2, reg3;
    sqlite3BeginWriteOperation(pParse, 0, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( isVirtual ){
      sqlite3VdbeAddOp0(v, OP_VBegin);
    }
#endif

    /* If the file format and encoding in the database have not been set, 
    ** set them now.
    */
    reg1 = pParse->regRowid = ++pParse->nMem;
    reg2 = pParse->regRoot = ++pParse->nMem;
    reg3 = ++pParse->nMem;
    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, 1);   /* file_format */
    sqlite3VdbeUsesBtree(v, iDb);

    j1 = sqlite3VdbeAddOp1(v, OP_If, reg3);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp2(v, OP_Integer, fileFormat, reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 1, reg3);
    sqlite3VdbeAddOp2(v, OP_Integer, ENC(db), reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, 4, reg3);
    sqlite3VdbeJumpHere(v, j1);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left on the top of the stack.
    ** The rowid value is needed by the code that sqlite3EndTable will
    ** generate.
    */
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
    if( isView || isVirtual ){
      sqlite3VdbeAddOp2(v, OP_Integer, 0, reg2);
    }else
#endif
    {
      sqlite3VdbeAddOp2(v, OP_CreateTable, iDb, reg2);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp2(v, OP_NewRowid, 0, reg1);
    sqlite3VdbeAddOp2(v, OP_Null, 0, reg3);
    sqlite3VdbeAddOp3(v, OP_Insert, 0, reg3, reg1);
    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
    sqlite3VdbeAddOp0(v, OP_Close);

  }

  /* Normal (non-error) return. */
  return;

  /* If an error occurs, we jump here */
begin_table_error:

    ** a schema-lock excludes all other database users, the write-lock would
    ** be redundant.
    */
    if( pSelect ){
      SelectDest dest;
      Table *pSelTab;


      sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
      sqlite3VdbeChangeP5(v, 1);
      pParse->nTab = 2;
      sqlite3SelectDestInit(&dest, SRT_Table, 1);
      sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);
      sqlite3VdbeAddOp1(v, OP_Close, 1);
      if( pParse->nErr==0 ){
        pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSelect);

    ** SQLITE_MASTER table.  We just need to update that slot with all
    ** the information we've collected.  The rowid for the preallocated
    ** slot is the 2nd item on the stack.  The top of the stack is the
    ** root page for the new table (or a 0 if this is a view).
    */
    sqlite3NestedParse(pParse,
      "UPDATE %Q.%s "
         "SET type='%s', name=%Q, tbl_name=%Q, rootpage=#%d, sql=%Q "
       "WHERE rowid=#%d",
      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
      zType,
      p->zName,
      p->zName,
      pParse->regRoot,
      zStmt,
      pParse->regRowid
    );
    sqlite3_free(zStmt);
    sqlite3ChangeCookie(db, v, iDb);

#ifndef SQLITE_OMIT_AUTOINCREMENT
    /* Check to see if we need to create an sqlite_sequence table for
    ** keeping track of autoincrement keys.

** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  int r1 = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_Destroy, iTable, r1, iDb);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* OP_Destroy stores an in integer r1. If this integer
  ** is non-zero, then it is the root page number of a table moved to
  ** location iTable. The following code modifies the sqlite_master table to
  ** reflect this.
  **
  ** The "#%d" in the SQL is a special constant that means whatever value
  ** is on the top of the stack.  See sqlite3RegisterExpr().
  */
  sqlite3NestedParse(pParse, 
     "UPDATE %Q.%s SET rootpage=%d WHERE #%d AND rootpage=#%d",
     pParse->db->aDb[iDb].zName, SCHEMA_TABLE(iDb), iTable, r1, r1);
#endif
  sqlite3ReleaseTempReg(pParse, r1);
}

/*
** Write VDBE code to erase table pTab and all associated indices on disk.
** Code to update the sqlite_master tables and internal schema definitions
** in case a root-page belonging to another table is moved by the btree layer
** is also added (this can happen with an auto-vacuum database).

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto exit_create_index;


    /* Create the rootpage for the index
    */
    sqlite3BeginWriteOperation(pParse, 1, iDb);

    sqlite3VdbeAddOp2(v, OP_CreateIndex, iDb, iMem);

    /* Gather the complete text of the CREATE INDEX statement into
    ** the zStmt variable
    */
    if( pStart && pEnd ){
      /* A named index with an explicit CREATE INDEX statement */
      zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
        onError==OE_None ? "" : " UNIQUE",
        pEnd->z - pName->z + 1,
        pName->z);
    }else{
      /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
      /* zStmt = sqlite3MPrintf(""); */
      zStmt = 0;
    }

    /* Add an entry in sqlite_master for this index
    */
    sqlite3NestedParse(pParse, 
        "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#%d,%Q);",
        db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
        pIndex->zName,
        pTab->zName,
        iMem,
        zStmt
    );

    sqlite3_free(zStmt);

    /* Fill the index with data and reparse the schema. Code an OP_Expire
    ** to invalidate all pre-compiled statements.
    */
    if( pTblName ){
      sqlite3RefillIndex(pParse, pIndex, iMem);

**    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
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.157 2008/01/12 12:48:08 drh 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.

    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
    return 1;
  }
#endif
  return 0;
}















/*
** Allocate nVal contiguous memory cells and return the index of the
** first. Also pop nVal elements from the stack and store them in the 
** registers. The element on the top of the stack is stored in the
** register with the largest index.
*/
int sqlite3StackToReg(Parse *p, int nVal){
  int i;
  int iRet = p->nMem+1;
  Vdbe *v = sqlite3GetVdbe(p);
  assert(v);
  p->nMem += nVal;
  for(i=nVal-1; i>=0; i--){
    sqlite3VdbeAddOp2(v, OP_Move, 0, iRet+i);
  }
  return iRet;
}









/*
** Generate code that will open a table for reading.
*/
void sqlite3OpenTable(
  Parse *p,       /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */

**    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 1.343 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

  const Token *pToken     /* Argument token */
){
  return sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
}

/*
** When doing a nested parse, you can include terms in an expression
** that look like this:   #1 #2 ...  These terms refer to registers
** in the virtual machine.  #N is the N-th register.

**
** This routine is called by the parser to deal with on of those terms.
** It immediately generates code to store the value in a memory location.
** The returns an expression that will code to extract the value from
** that memory location as needed.
*/
Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
  Vdbe *v = pParse->pVdbe;
  Expr *p;

  if( pParse->nested==0 ){
    sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
    return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
  }
  if( v==0 ) return 0;
  p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
  if( p==0 ){
    return 0;  /* Malloc failed */
  }
  p->iTable = atoi((char*)&pToken->z[1]);


  return p;
}

/*
** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
*/

**    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 1.223 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 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:

      useTempTable = 1;
    }

    if( useTempTable ){
      /* Generate the subroutine that SELECT calls to process each row of
      ** the result.  Store the result in a temporary table
      */
      int regRec, regRowid;

      srcTab = pParse->nTab++;
      regRec = sqlite3GetTempReg(pParse);
      regRowid = sqlite3GetTempReg(pParse);
      sqlite3VdbeResolveLabel(v, iInsertBlock);
      sqlite3VdbeAddOp3(v, OP_RegMakeRec, regFromSelect, nColumn, regRec);

      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, srcTab, regRec, regRowid);
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
      sqlite3ReleaseTempReg(pParse, regRec);
      sqlite3ReleaseTempReg(pParse, regRowid);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqlite3VdbeJumpHere(v, iInitCode);
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, 0);

  if( useTempTable ){
    iBreak = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, srcTab, iBreak);
    iCont = sqlite3VdbeCurrentAddr(v);
  }else if( pSelect ){
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
    sqlite3VdbeResolveLabel(v, iInsertBlock);

    sqlite3VdbeAddOp2(v, OP_StackDepth, -1, 0);
  }

  /* Allocate registers for holding the rowid of the new row,
  ** the content of the new row, and the assemblied row record.
  */
  regRecord = ++pParse->nMem;

      /* The row that the VUpdate opcode will delete: none */
      sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
    }
    if( keyColumn>=0 ){
      if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, keyColumn, regRowid);
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+keyColumn, regRowid);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, 0);
        pOp = sqlite3VdbeGetOp(v, sqlite3VdbeCurrentAddr(v) - 1);
        if( pOp && pOp->opcode==OP_Null ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;

        }
      }
      if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, iRegStore);
      }else if( useTempTable ){
        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, iRegStore); 
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+j, iRegStore);
      }else{
        sqlite3ExprCode(pParse, pList->a[j].pExpr, iRegStore);
      }
    }

    /* Generate code to check constraints and generate index keys and
    ** do the insertion.

  */
  sqlite3VdbeResolveLabel(v, endOfLoop);
  if( useTempTable ){
    sqlite3VdbeAddOp2(v, OP_Next, srcTab, iCont);
    sqlite3VdbeResolveLabel(v, iBreak);
    sqlite3VdbeAddOp2(v, OP_Close, srcTab, 0);
  }else if( pSelect ){

    sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
    sqlite3VdbeResolveLabel(v, iCleanup);
  }

  if( !IsVirtual(pTab) && !isView ){
    /* Close all tables opened */
    sqlite3VdbeAddOp2(v, OP_Close, baseCur, 0);

){
  int i;
  Vdbe *v;
  int nIdx;
  Index *pIdx;
  int pik_flags;
  int regData;
  int regRec;

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
  for(i=nIdx-1; i>=0; i--){
    if( aRegIdx[i]==0 ) continue;
    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
  }
  regData = regRowid + 1;
  regRec = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, regData, pTab->nCol, regRec);
  sqlite3TableAffinityStr(v, pTab);
#ifndef SQLITE_OMIT_TRIGGER
  if( newIdx>=0 ){

    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regRowid);

  }
#endif
  if( pParse->nested ){
    pik_flags = 0;
  }else{
    pik_flags = OPFLAG_NCHANGE;
    pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
  }
  if( appendBias ){
    pik_flags |= OPFLAG_APPEND;
  }
  sqlite3VdbeAddOp3(v, OP_Insert, baseCur, regRec, regRowid);
  if( !pParse->nested ){
    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
  }
  sqlite3VdbeChangeP5(v, pik_flags);
}

/*
** Generate code that will open cursors for a table and for all
** indices of that table.  The "baseCur" parameter is the cursor number used
** for the table.  Indices are opened on subsequent cursors.
**

  int addr1, addr2;                /* Loop addresses */
  int emptyDestTest;               /* Address of test for empty pDest */
  int emptySrcTest;                /* Address of test for empty pSrc */
  Vdbe *v;                         /* The VDBE we are building */
  KeyInfo *pKey;                   /* Key information for an index */
  int regAutoinc;                  /* Memory register used by AUTOINC */
  int destHasUniqueIdx = 0;        /* True if pDest has a UNIQUE index */
  int regData, regRowid;           /* Registers holding data and rowid */

  if( pSelect==0 ){
    return 0;   /* Must be of the form  INSERT INTO ... SELECT ... */
  }
  if( pDest->pTrigger ){
    return 0;   /* tab1 must not have triggers */
  }

    emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
  }else{
    emptyDestTest = 0;
  }
  sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
  emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
  regData = sqlite3GetTempReg(pParse);
  regRowid = sqlite3GetTempReg(pParse);
  if( pDest->iPKey>=0 ){
    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);

    addr2 = sqlite3VdbeAddOp3(v, OP_NotExists, iDest, 0, regRowid);
    sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
                      "PRIMARY KEY must be unique", P4_STATIC);
    sqlite3VdbeJumpHere(v, addr2);
    autoIncStep(pParse, regAutoinc, regRowid);
  }else if( pDest->pIndex==0 ){
    addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, regRowid);
  }else{
    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, regRowid);
    assert( pDest->autoInc==0 );
  }
  sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
  sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
  sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
  sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
  sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1);
  autoIncEnd(pParse, iDbDest, pDest, regAutoinc);
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    assert( pSrcIdx );
    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
    sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, iDbSrc,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pSrcIdx->zName));
    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
    sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, iDbDest,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pDestIdx->zName));
    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, regData);
    sqlite3VdbeAddOp3(v, OP_IdxInsert, iDest, regData, 1);
    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
    sqlite3VdbeJumpHere(v, addr1);
  }
  sqlite3VdbeJumpHere(v, emptySrcTest);
  sqlite3ReleaseTempReg(pParse, regRowid);
  sqlite3ReleaseTempReg(pParse, regData);
  sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
  sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
  if( emptyDestTest ){
    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
    sqlite3VdbeJumpHere(v, emptyDestTest);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
    return 0;
  }else{
    return 1;
  }
}
#endif /* SQLITE_OMIT_XFER_OPT */

**    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 1.398 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.

/*
** Insert code into "v" that will push the record on the top of the
** stack into the sorter.
*/
static void pushOntoSorter(
  Parse *pParse,         /* Parser context */
  ExprList *pOrderBy,    /* The ORDER BY clause */
  Select *pSelect,       /* The whole SELECT statement */
  int regData            /* Register holding data to be sorted */
){
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3VdbeAddOp2(v, OP_Move, regData, regBase+nExpr+1);
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, regBase, nExpr + 2, regRecord);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    int iLimit;
    if( pSelect->pOffset ){
      iLimit = pSelect->iOffset+1;
    }else{
      iLimit = pSelect->iLimit;
    }
    addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, iLimit);
    sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1);
    addr2 = sqlite3VdbeAddOp0(v, OP_Goto);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp1(v, OP_Last, pOrderBy->iECursor);
    sqlite3VdbeAddOp1(v, OP_Delete, pOrderBy->iECursor);
    sqlite3VdbeJumpHere(v, addr2);
    pSelect->iLimit = -1;
  }
}

/*
** Add code to implement the OFFSET
*/
static void codeOffset(
  Vdbe *v,          /* Generate code into this VM */
  Select *p,        /* The SELECT statement being coded */
  int iContinue     /* Jump here to skip the current record */

){
  if( p->iOffset>=0 && iContinue!=0 ){
    int addr;
    sqlite3VdbeAddOp2(v, OP_AddImm, p->iOffset, -1);
    addr = sqlite3VdbeAddOp1(v, OP_IfNeg, p->iOffset);



    sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue);
    VdbeComment((v, "skip OFFSET records"));
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*

  assert( pEList!=0 );

  /* If there was a LIMIT clause on the SELECT statement, then do the check
  ** to see if this row should be output.
  */
  hasDistinct = distinct>=0 && pEList->nExpr>0;
  if( pOrderBy==0 && !hasDistinct ){
    codeOffset(v, p, iContinue);
  }

  /* Pull the requested columns.
  */
  if( nColumn>0 ){
    n = nColumn;
  }else{

  ** part of the result.
  */
  if( hasDistinct ){
    assert( pEList!=0 );
    assert( pEList->nExpr==nColumn );
    codeDistinct(v, distinct, iContinue, nColumn, iMem);
    if( pOrderBy==0 ){
      codeOffset(v, p, iContinue);
    }
  }

  if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){
    return 0;
  }

    }
#endif

    /* Store the result as data using a unique key.
    */
    case SRT_Table:
    case SRT_EphemTab: {
      int r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp3(v, OP_RegMakeRec, iMem, nColumn, r1);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p, r1);
      }else{
        int r2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2);
        sqlite3VdbeAddOp3(v, OP_Insert, iParm, r1, r2);
        sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
        sqlite3ReleaseTempReg(pParse, r2);
      }
      sqlite3ReleaseTempReg(pParse, r1);
      break;
    }

#ifndef SQLITE_OMIT_SUBQUERY
    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
    ** item into the set table with bogus data.
    */
    case SRT_Set: {
      int addr2;

      assert( nColumn==1 );
      addr2 = sqlite3VdbeAddOp2(v, OP_IsNull, iMem, 0);
      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity);
      if( pOrderBy ){
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */

        pushOntoSorter(pParse, pOrderBy, p, iMem);
      }else{
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_RegMakeRec, iMem, 1, r1, &p->affinity, 1);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

    /* If any row exist in the result set, record that fact and abort.
    */
    case SRT_Exists: {
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell and break out
    ** of the scan loop.
    */
    case SRT_Mem: {
      assert( nColumn==1 );

      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p, iMem);
      }else{
        sqlite3VdbeAddOp2(v, OP_Move, iMem, iParm);
        /* The LIMIT clause will jump out of the loop for us */
      }
      break;
    }
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */

    /* Send the data to the callback function or to a subroutine.  In the
    ** case of a subroutine, the subroutine itself is responsible for
    ** popping the data from the stack.
    */
    case SRT_Subroutine:
    case SRT_Callback: {
      if( pOrderBy ){
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_RegMakeRec, iMem, nColumn, r1);
        pushOntoSorter(pParse, pOrderBy, p, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }else if( eDest==SRT_Subroutine ){
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }else{
        sqlite3VdbeAddOp2(v, OP_ResultRow, iMem, nColumn);
      }
      break;
    }

  iTab = pOrderBy->iECursor;
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, pseudoTab, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, pseudoTab, nColumn);
  }
  addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, brk);
  codeOffset(v, p, cont);
  regRow = sqlite3GetTempReg(pParse);
  regRowid = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr + 1, regRow);
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid);

** the reuse of the same limit and offset registers across multiple
** SELECT statements.
*/
static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
  Vdbe *v = 0;
  int iLimit = 0;
  int iOffset;
  int addr1;

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** contraversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
  */
  if( p->pLimit ){
    p->iLimit = iLimit = ++pParse->nMem;

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pLimit, iLimit);
    sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit);

    VdbeComment((v, "LIMIT counter"));
    sqlite3VdbeAddOp2(v, OP_IfZero, iLimit, iBreak);

  }
  if( p->pOffset ){
    p->iOffset = iOffset = ++pParse->nMem;
    if( p->pLimit ){
      pParse->nMem++;   /* Allocate an extra register for limit+offset */
    }
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pOffset, iOffset);
    sqlite3VdbeAddOp1(v, OP_MustBeInt, iOffset);

    VdbeComment((v, "OFFSET counter"));
    addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iOffset);

    sqlite3VdbeAddOp2(v, OP_Integer, 0, iOffset);
    sqlite3VdbeJumpHere(v, addr1);
    if( p->pLimit ){
      sqlite3VdbeAddOp3(v, OP_Add, iLimit, iOffset, iOffset+1);



      VdbeComment((v, "LIMIT+OFFSET"));
      addr1 = sqlite3VdbeAddOp1(v, OP_IfPos, iLimit);

      sqlite3VdbeAddOp2(v, OP_Integer, -1, iOffset+1);

      sqlite3VdbeJumpHere(v, addr1);



    }
  }
}

/*
** Allocate a virtual index to use for sorting.
*/
static void createSortingIndex(Parse *pParse, Select *p, ExprList *pOrderBy){

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.648 2008/01/12 12:48:08 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds

  int nTableLock;        /* Number of locks in aTableLock */
  TableLock *aTableLock; /* Required table locks for shared-cache mode */
#endif

  /* Above is constant between recursions.  Below is reset before and after
  ** each recursion */

  int regRowid;        /* Register holding rowid of CREATE TABLE entry */
  int regRoot;         /* Register holding root page number for new objects */
  int nVar;            /* Number of '?' variables seen in the SQL so far */
  int nVarExpr;        /* Number of used slots in apVarExpr[] */
  int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
  Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
  u8 explain;          /* True if the EXPLAIN flag is found on the query */
  Token sErrToken;     /* The token at which the error occurred */
  Token sNameToken;    /* Token with unqualified schema object name */

  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

void sqlite3StrAccumAppend(StrAccum*,const char*,int);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumReset(StrAccum*);

int sqlite3StackToReg(Parse *, int);

void sqlite3SelectDestInit(SelectDest*,int,int);

/*
** The interface to the LEMON-generated parser
*/
void *sqlite3ParserAlloc(void*(*)(size_t));
void sqlite3ParserFree(void*, void(*)(void*));

**
** 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 1.693 2008/01/12 12:48:08 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor

** is working correctly.   This variable has no function other than to
** help verify the correct operation of the library.
*/
#ifdef SQLITE_TEST
int sqlite3_max_blobsize = 0;
#endif

/*
** Test a register to see if it exceeds the current maximum blob size.
** If it does, record the new maximum blob size.
*/
#ifdef SQLITE_TEST
# define UPDATE_MAX_BLOBSIZE(P)  if( ((P)->flags&(MEM_Str|MEM_Blob))!=0 \
                                      && (P)->n>sqlite3_max_blobsize ) \
                                          {sqlite3_max_blobsize = (P)->n;}
#else
# define UPDATE_MAX_BLOBSIZE(P)
#endif

/*
** Release the memory associated with the given stack level.  This
** leaves the Mem.flags field in an inconsistent state.
*/
#define Release(P) if((P)->flags&MEM_Dyn){ sqlite3VdbeMemRelease(P); }

/*

    }
    pOp->p4type = P4_DYNAMIC;
    pOp->p4.z = pOut->z;
    pOp->p1 = pOut->n;
    if( pOp->p1>SQLITE_MAX_LENGTH ){
      goto too_big;
    }
    UPDATE_MAX_BLOBSIZE(pOut);
    break;
  }
#endif
  if( pOp->p1>SQLITE_MAX_LENGTH ){
    goto too_big;
  }
  /* Fall through to the next case, OP_String */
}
  
/* Opcode: String P1 P2 * P4 *
**
** The string value P4 of length P1 (bytes) is stored in register P2
** or is pushed onto the stack if P2==0.
*/
case OP_String: {          /* out2-prerelease */
  assert( pOp->p4.z!=0 );
  pOut->flags = MEM_Str|MEM_Static|MEM_Term;
  pOut->z = pOp->p4.z;
  pOut->n = pOp->p1;
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Null * P2 * * *
**
** Write a NULL into register P2 or push a NULL onto the stack 
** if P2==0.

** the blob as P4. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {                /* out2-prerelease */
  assert( pOp->p1 <= SQLITE_MAX_LENGTH );
  sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
  pOut->enc = encoding;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 P2 * * *
**
** The value of variable P1 is written into register P2 or pushed

  assert( j>=0 && j<p->nVar );

  pVar = &p->aVar[j];
  if( sqlite3VdbeMemTooBig(pVar) ){
    goto too_big;
  }
  sqlite3VdbeMemShallowCopy(pOut, &p->aVar[j], MEM_Static);
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Pop P1 * * * *
**
** P1 elements are popped off of the top of stack and discarded.
*/

      Deephemeralize(pOut);
    }
  }
  REGISTER_TRACE(pOp->p2, pOut);
  break;
}



































/* Opcode: ResultRow P1 P2 *
**
** The registers P1 throught P1+P2-1 contain a single row of
** results. This opcode causes the sqlite3_step() call to terminate
** with an SQLITE_ROW return code and it sets up the sqlite3_stmt
** structure to provide access to the top P1 values as the result
** row.  When the sqlite3_step() function is run again, the top P1

  zNew[nByte+1] = 0;
  Release(pOut);
  pOut->n = nByte;
  pOut->flags = MEM_Str|MEM_Dyn|MEM_Term;
  pOut->xDel = 0;
  pOut->enc = encoding;
  pOut->z = zNew;
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: Add P1 P2 P3 * *
**
** Add the value in P1 to the value in P2 and store the result in P3.
** If either operand is NULL, the result is NULL.

  }else{
    pOut = &p->aMem[pOp->p3];
  }
  sqlite3VdbeMemMove(pOut, &ctx.s);
  if( sqlite3VdbeMemTooBig(pOut) ){
    goto too_big;
  }
  UPDATE_MAX_BLOBSIZE(pOut);
  break;
}

/* Opcode: BitAnd P1 P2 P3 * *
**
** Take the bit-wise AND of the values in register P1 and P2 and
** store the result in register P3.

  if( pIn1->flags & MEM_Null ) break;
  assert( MEM_Str==(MEM_Blob>>3) );
  pIn1->flags |= (pIn1->flags&MEM_Blob)>>3;
  applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
  rc = ExpandBlob(pIn1);
  assert( pIn1->flags & MEM_Str );
  pIn1->flags &= ~(MEM_Int|MEM_Real|MEM_Blob);
  UPDATE_MAX_BLOBSIZE(pIn1);
  break;
}

/* Opcode: ToBlob P1 * * * *
**
** Force the value in register P1 to be a BLOB.
** If the value is numeric, convert it to a string first.

  if( pIn1->flags & MEM_Null ) break;
  if( (pIn1->flags & MEM_Blob)==0 ){
    applyAffinity(pIn1, SQLITE_AFF_TEXT, encoding);
    assert( pIn1->flags & MEM_Str );
    pIn1->flags |= MEM_Blob;
  }
  pIn1->flags &= ~(MEM_Int|MEM_Real|MEM_Str);
  UPDATE_MAX_BLOBSIZE(pIn1);
  break;
}

/* Opcode: ToNumeric P1 * * * *
**
** Force the value in register P1 to be numeric (either an
** integer or a floating-point number.)

  }

  /* pDest->z might be pointing to sMem.zShort[].  Fix that so that we
  ** can abandon sMem */
  rc = sqlite3VdbeMemMakeWriteable(pDest);

op_column_out:
  UPDATE_MAX_BLOBSIZE(pDest);
  REGISTER_TRACE(pOp->p3, pDest);
  break;
}

/* Opcode: MakeRecord P1 P2 P4
**
** Convert the top abs(P1) entries of the stack into a single entry

  }
  if( nZero ){
    pOut->u.i = nZero;
    pOut->flags |= MEM_Zero;
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever converted to text */
  REGISTER_TRACE(pOp->p3, pOut);
  UPDATE_MAX_BLOBSIZE(pOut);

  /* If a NULL was encountered and jumpIfNull is non-zero, take the jump. */
  if( jumpIfNull && containsNull ){
    pc = jumpIfNull - 1;
  }
  break;
}

** executing this instruction.
*/
case OP_ReadCookie: {               /* out2-prerelease */
  int iMeta;
  int iDb = pOp->p1;
  int iCookie = pOp->p3;

  assert( pOp->p3<SQLITE_N_BTREE_META );
  if( iDb<0 ){
    iDb = (-1*(iDb+1));
    iCookie *= -1;
  }
  assert( iDb>=0 && iDb<db->nDb );
  assert( db->aDb[iDb].pBt!=0 );
  assert( (p->btreeMask & (1<<iDb))!=0 );

    assert( pC->nData<=SQLITE_MAX_LENGTH );
    pOut->z = pC->pData;
    pOut->flags = MEM_Blob|MEM_Ephem;
  }else{
    pOut->flags = MEM_Null;
  }
  pOut->enc = SQLITE_UTF8;  /* In case the blob is ever cast to text */
  UPDATE_MAX_BLOBSIZE(pOut);
  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.  If p2==0 then push the integer.

  }else{
    pIn1->z = z;
    pIn1->n = strlen(z);
    pIn1->flags = MEM_Str | MEM_Dyn | MEM_Term;
    pIn1->xDel = 0;
  }
  pIn1->enc = SQLITE_UTF8;
  UPDATE_MAX_BLOBSIZE(pIn1);
  sqlite3VdbeChangeEncoding(pIn1, encoding);
  sqlite3_free(aRoot);
  break;
}
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

/* Opcode: FifoWrite P1 * * * *

  assert( pOp->p1>0 && pOp->p1<=p->nMem );
  pMem = &p->aMem[pOp->p1];
  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
  if( rc==SQLITE_ERROR ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(pMem), (char*)0);
  }
  UPDATE_MAX_BLOBSIZE(pMem);
  if( sqlite3VdbeMemTooBig(pMem) ){
    goto too_big;
  }
  break;
}

      pDest = &p->aMem[pOp->p3];
      REGISTER_TRACE(pOp->p3, pDest);
    }else{
      pDest = ++pTos;
      pDest->flags = 0;
    }
    sqlite3VdbeMemMove(pDest, &sContext.s);
    UPDATE_MAX_BLOBSIZE(pDest);

    if( sqlite3SafetyOn(db) ){
      goto abort_due_to_misuse;
    }
    if( sqlite3VdbeMemTooBig(pDest) ){
      goto too_big;
    }

      pOp->cycles += elapse;
      pOp->cnt++;
#if 0
        fprintf(stdout, "%10lld ", elapse);
        sqlite3VdbePrintOp(stdout, origPc, &p->aOp[origPc]);
#endif
    }










#endif

    /* The following code adds nothing to the actual functionality
    ** of the program.  It is only here for testing and debugging.
    ** On the other hand, it does burn CPU cycles every time through
    ** the evaluator loop.  So we can leave it out when NDEBUG is defined.
    */

/*
** 2006 June 10
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to help implement virtual tables.
**
** $Id: vtab.c,v 1.61 2008/01/12 12:48:08 drh Exp $
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
#include "sqliteInt.h"

static int createModule(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */

    }
    zStmt = sqlite3MPrintf(db, "CREATE VIRTUAL TABLE %T", &pParse->sNameToken);

    /* A slot for the record has already been allocated in the 
    ** SQLITE_MASTER table.  We just need to update that slot with all
    ** the information we've collected.  
    **
    ** The VM register number pParse->regRowid holds the rowid of an


    ** entry in the sqlite_master table tht was created for this vtab
    ** by sqlite3StartTable().
    */
    iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
    sqlite3NestedParse(pParse,
      "UPDATE %Q.%s "
         "SET type='table', name=%Q, tbl_name=%Q, rootpage=0, sql=%Q "
       "WHERE rowid=#%d",
      db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
      pTab->zName,
      pTab->zName,
      zStmt,
      pParse->regRowid
    );
    sqlite3_free(zStmt);
    v = sqlite3GetVdbe(pParse);
    sqlite3ChangeCookie(db, v, iDb);

    sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
    zWhere = sqlite3MPrintf(db, "name='%q'", pTab->zName);

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing UNION, INTERSECT and EXCEPT operators
# in SELECT statements.
#
# $Id: select4.test,v 1.25 2008/01/12 12:48:09 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Most tests in this file depend on compound-select. But there are a couple
# right at the end that test DISTINCT, so we cannot omit the entire file.
#

    SELECT * FROM (SELECT 1 AS a, 2 AS b UNION ALL SELECT 3 AS e, 4 AS b)
     WHERE b>0
  }
} {a 1 b 2 a 3 b 4}
} ;# ifcapable subquery

} ;# ifcapable compound

# Try combining DISTINCT, LIMIT, and OFFSET.  Make sure they all work
# together.
#
do_test select4-10.1 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log
  }
} {0 1 2 3 4 5}
do_test select4-10.2 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log LIMIT 4
  }
} {0 1 2 3}
do_test select4-10.3 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log LIMIT 0
  }
} {}
do_test select4-10.4 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log LIMIT -1
  }
} {0 1 2 3 4 5}
do_test select4-10.5 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log LIMIT -1 OFFSET 2
  }
} {2 3 4 5}
do_test select4-10.6 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log LIMIT 3 OFFSET 2
  }
} {2 3 4}
do_test select4-10.7 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY +log LIMIT 3 OFFSET 20
  }
} {}
do_test select4-10.8 {
  execsql {
    SELECT DISTINCT log FROM t1 ORDER BY log LIMIT 0 OFFSET 3
  }
} {}
do_test select4-10.9 {
breakpoint
  execsql {
    SELECT DISTINCT max(n), log FROM t1 ORDER BY +log; -- LIMIT 2 OFFSET 1
  }
} {31 5}


finish_test

# 2001 September 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library. 
#
# The focus of this file is testing that LIMIT and OFFSET work for
# unusual combinations SELECT statements.
#
# $Id: select8.test,v 1.1 2008/01/12 12:48:09 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

execsql {
  CREATE TABLE songs(songid, artist, timesplayed);
  INSERT INTO songs VALUES(1,'one',1);
  INSERT INTO songs VALUES(2,'one',2);
  INSERT INTO songs VALUES(3,'two',3);
  INSERT INTO songs VALUES(4,'three',5);
  INSERT INTO songs VALUES(5,'one',7);
  INSERT INTO songs VALUES(6,'two',11);
}
set result [execsql {
  SELECT DISTINCT artist,sum(timesplayed) AS total      
  FROM songs      
  GROUP BY LOWER(artist)      
}]
puts result=$result
do_test select8-1.1 {
  execsql {
    SELECT DISTINCT artist,sum(timesplayed) AS total      
    FROM songs      
    GROUP BY LOWER(artist)      
    LIMIT 1 OFFSET 1
  }
} [lrange $result 2 3]
do_test select8-1.2 {
  execsql {
    SELECT DISTINCT artist,sum(timesplayed) AS total      
    FROM songs      
    GROUP BY LOWER(artist)      
    LIMIT 2 OFFSET 1
  }
} [lrange $result 2 5]
do_test select8-1.3 {
  execsql {
    SELECT DISTINCT artist,sum(timesplayed) AS total      
    FROM songs      
    GROUP BY LOWER(artist)      
    LIMIT -1 OFFSET 2
  }
} [lrange $result 4 end]


finish_test