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 1.36 2008/01/09 23:04:12 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

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

  /* Establish a read-lock on the table at the shared-cache level. */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  iIdxCur = pParse->nTab;
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);







    /* Open a cursor to the index to be analyzed
    */
    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb,
        (char *)pKey, P4_KEYINFO_HANDOFF);
    VdbeComment((v, "%s", pIdx->zName));
    nCol = pIdx->nColumn;



    if( iMem+nCol*2>=pParse->nMem ){
      pParse->nMem = iMem+nCol*2+1;
    }
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, iIdxCur, nCol+1);

    /* Memory cells are used as follows:
    **
    **    mem[iMem]:             The total number of rows in the table.
    **    mem[iMem+1]:           Number of distinct values in column 1

    /* Do the analysis.
    */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp2(v, OP_Column, iIdxCur, i);
      sqlite3VdbeAddOp1(v, OP_SCopy, iMem+nCol+i+1);
      sqlite3VdbeAddOp0(v, OP_Ne );  /* Use Collating sequence */
      sqlite3VdbeChangeP5(v, SQLITE_JUMPIFNULL);
    }
    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
    for(i=0; i<nCol; i++){

      addr = sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1);
      sqlite3VdbeChangeP2(v, topOfLoop + 3*i + 3, addr);
      sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1);
    }
    sqlite3VdbeResolveLabel(v, endOfLoop);
    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);

    /* Store the results.  

    **
    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp1(v, OP_SCopy, iMem);
    addr = sqlite3VdbeAddOp0(v, OP_IfNot);
    sqlite3VdbeAddOp1(v, OP_NewRowid, iStatCur);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pIdx->zName, 0);

    sqlite3VdbeAddOp1(v, OP_SCopy, iMem);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, " ", 0);
      sqlite3VdbeAddOp0(v, OP_Concat);
      sqlite3VdbeAddOp2(v, OP_Add, iMem, iMem+i+1);
      sqlite3VdbeAddOp2(v, OP_AddImm, 0, -1);
      sqlite3VdbeAddOp2(v, OP_Divide, iMem+i+1, 0);
      sqlite3VdbeAddOp0(v, OP_ToInt);
      sqlite3VdbeAddOp0(v, OP_Concat);
    }
    sqlite3VdbeAddOp4(v, OP_MakeRecord, 3, 0, 0, "aaa", 0);


    sqlite3CodeInsert(pParse, iStatCur, OPFLAG_APPEND);
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Generate code that will cause the most recent index analysis to
** be laoded into internal hash tables where is can be used.

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.462 2008/01/09 23:04:12 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.

  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab;       /* Btree cursor used for pTab */
  int iIdx = pParse->nTab+1;     /* Btree cursor used for pIndex */
  int addr1;                     /* Address of top of loop */
  int tnum;                      /* Root page of index */
  Vdbe *v;                       /* Generate code into this virtual machine */
  KeyInfo *pKey;                 /* KeyInfo for index */


  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);

#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
      db->aDb[iDb].zName ) ){
    return;

  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, iDb, 
                    (char *)pKey, P4_KEYINFO_HANDOFF);
  if( memRootPage>=0 ){
    sqlite3VdbeChangeP5(v, 1);
  }
  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);

  sqlite3GenerateIndexKey(v, pIndex, iTab);
  if( pIndex->onError!=OE_None ){
    int curaddr = sqlite3VdbeCurrentAddr(v);
    int addr2 = curaddr+4;
    sqlite3VdbeChangeP2(v, curaddr-1, addr2);
    sqlite3VdbeAddOp1(v, OP_Rowid, iTab);
    sqlite3VdbeAddOp2(v, OP_AddImm, 0, 1);
    sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx, addr2, 0, 0, P4_INT32);

    sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, OE_Abort, 0,
                    "indexed columns are not unique", P4_STATIC);
    assert( db->mallocFailed || addr2==sqlite3VdbeCurrentAddr(v) );

  }
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, 0);

  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeJumpHere(v, addr1);
  sqlite3VdbeAddOp1(v, OP_Close, iTab);
  sqlite3VdbeAddOp1(v, OP_Close, iIdx);
}

/*

**    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 1.155 2008/01/09 23:04:12 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.

      if( IsVirtual(pTab) ){
        const char *pVtab = (const char *)pTab->pVtab;
        pParse->pVirtualLock = pTab;
        sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVtab, P4_VTAB);
      }else
#endif
      {
        sqlite3GenerateRowDelete(db, v, pTab, iCur, iRowid, pParse->nested==0);
      }
    }

    /* If there are row triggers, close all cursors then invoke
    ** the AFTER triggers
    */
    if( triggers_exist ){

**       memory cell iRowid.
**
** This routine pops the top of the stack to remove the record number
** and then generates code to remove both the table record and all index
** entries that point to that record.
*/
void sqlite3GenerateRowDelete(
  sqlite3 *db,       /* The database containing the index */
  Vdbe *v,           /* Generate code into this VDBE */
  Table *pTab,       /* Table containing the row to be deleted */
  int iCur,          /* Cursor number for the table */
  int iRowid,        /* Memory cell that contains the rowid to delete */
  int count          /* Increment the row change counter */
){
  int addr;



  addr = sqlite3VdbeAddOp3(v, OP_NotExists, iCur, 0, iRowid);
  sqlite3GenerateRowIndexDelete(v, pTab, iCur, 0);
  sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
  if( count ){
    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
  }
  sqlite3VdbeJumpHere(v, addr);
}

**   2.  Read/write cursors for all indices of pTab must be open as
**       cursor number iCur+i for the i-th index.
**
**   3.  The "iCur" cursor must be pointing to the row that is to be
**       deleted.
*/
void sqlite3GenerateRowIndexDelete(
  Vdbe *v,           /* Generate code into this VDBE */
  Table *pTab,       /* Table containing the row to be deleted */
  int iCur,          /* Cursor number for the table */
  int *aRegIdx       /* Only delete if aRegIdx!=0 && aRegIdx[i]>0 */
){
  int i;
  Index *pIdx;

  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
    sqlite3GenerateIndexKey(v, pIdx, iCur);
    sqlite3VdbeAddOp1(v, OP_IdxDelete, iCur+i);
  }
}

/*
** Generate code that will assemble an index key and put it on the top
** of the tack.  The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
** the entry that needs indexing.





*/
void sqlite3GenerateIndexKey(
  Vdbe *v,           /* Generate code into this VDBE */
  Index *pIdx,       /* The index for which to generate a key */
  int iCur           /* Cursor number for the pIdx->pTable table */

){

  int j;
  Table *pTab = pIdx->pTable;





  sqlite3VdbeAddOp1(v, OP_Rowid, iCur);
  for(j=0; j<pIdx->nColumn; j++){
    int idx = pIdx->aiColumn[j];
    if( idx==pTab->iPKey ){
      sqlite3VdbeAddOp1(v, OP_Copy, -j);
    }else{
      sqlite3VdbeAddOp2(v, OP_Column, iCur, idx);
      sqlite3ColumnDefault(v, pTab, idx);
    }
  }
  sqlite3VdbeAddOp1(v, OP_MakeIdxRec, pIdx->nColumn);
  sqlite3IndexAffinityStr(v, pIdx);


}

**    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 1.341 2008/01/10 03:46:36 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

** its members, skipping duplicates.
**
** The cursor opened on the structure (database table, database index 
** or ephermal table) is stored in pX->iTable before this function returns.
** The returned value indicates the structure type, as follows:
**
**   IN_INDEX_ROWID - The cursor was opened on a database table.
**   IN_INDEX_INDEX - The cursor was opened on a database indec.
**   IN_INDEX_EPH -   The cursor was opened on a specially created and
**                    populated epheremal table.
**
** An existing structure may only be used if the SELECT is of the simple
** form:
**
**     SELECT <column> FROM <table>

        ** store it in the temporary table. If <expr> is a column, then use
        ** that columns affinity when building index keys. If <expr> is not
        ** a column, use numeric affinity.
        */
        int i;
        ExprList *pList = pExpr->pList;
        struct ExprList_item *pItem;


        if( !affinity ){
          affinity = SQLITE_AFF_NONE;
        }
        keyInfo.aColl[0] = pExpr->pLeft->pColl;

        /* Loop through each expression in <exprlist>. */


        for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
          Expr *pE2 = pItem->pExpr;

          /* If the expression is not constant then we will need to
          ** disable the test that was generated above that makes sure
          ** this code only executes once.  Because for a non-constant
          ** expression we need to rerun this code each time.
          */
          if( testAddr && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2, 0);
          sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &affinity, 1);
          sqlite3VdbeAddOp1(v, OP_IdxInsert, pExpr->iTable);
        }


      }
      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      break;
    }

    case TK_EXISTS:
    case TK_SELECT: {

      inReg = pExpr->iColumn;
      break;
    }
    case TK_IN: {
      int j1, j2, j3, j4, j5;
      char affinity;
      int eType;


      eType = sqlite3FindInIndex(pParse, pExpr, 0);

      /* Figure out the affinity to use to create a key from the results
      ** of the expression. affinityStr stores a static string suitable for
      ** P4 of OP_MakeRecord.
      */
      affinity = comparisonAffinity(pExpr);







      sqlite3VdbeAddOp1(v, OP_Integer, 1);

      /* Code the <expr> from "<expr> IN (...)". The temporary table
      ** pExpr->iTable contains the values that make up the (...) set.
      */
      sqlite3ExprCode(pParse, pExpr->pLeft, 0);
      sqlite3VdbeAddOp0(v, OP_SCopy);
      j1 = sqlite3VdbeAddOp0(v, OP_NotNull);
      sqlite3VdbeAddOp1(v, OP_Pop, 2);
      sqlite3VdbeAddOp0(v, OP_Null);
      j2  = sqlite3VdbeAddOp0(v, OP_Goto);
      sqlite3VdbeJumpHere(v, j1);
      if( eType==IN_INDEX_ROWID ){
        j3 = sqlite3VdbeAddOp3(v, OP_MustBeInt, 0, 0, 1);
        j4 = sqlite3VdbeAddOp1(v, OP_NotExists, pExpr->iTable);
        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
        sqlite3VdbeJumpHere(v, j3);
        sqlite3VdbeJumpHere(v, j4);
      }else{

        sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &affinity, 1);
        j5 = sqlite3VdbeAddOp1(v, OP_Found, pExpr->iTable);

      }
      sqlite3VdbeAddOp2(v, OP_AddImm, 0, -1);
      sqlite3VdbeJumpHere(v, j2);
      sqlite3VdbeJumpHere(v, j5);
      break;
    }
#endif
    case TK_BETWEEN: {
      Expr *pLeft = pExpr->pLeft;

**
** This routine might also cache the result and modify the pExpr tree
** so that it will make use of the cached result on subsequent evaluations
** rather than evaluate the whole expression again.  Trivial expressions are
** not cached.  If the expression is cached, its result is stored in a 
** memory location.
*/
void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr){
  Vdbe *v = pParse->pVdbe;
  VdbeOp *pOp;
  int iMem;
  int addr1, addr2;
  if( v==0 ) return;
  addr1 = sqlite3VdbeCurrentAddr(v);
  sqlite3ExprCode(pParse, pExpr, 0);
  addr2 = sqlite3VdbeCurrentAddr(v);
  if( addr2>addr1+1
   || ((pOp = sqlite3VdbeGetOp(v, addr1))!=0 && pOp->opcode==OP_Function) ){
    iMem = pExpr->iTable = ++pParse->nMem;
    sqlite3VdbeAddOp2(v, OP_Copy, 0, iMem);
    pExpr->op = TK_REGISTER;
  }
}
#endif

/*
** Generate code that pushes the value of every element of the given

**    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 1.221 2008/01/10 03:46:36 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:
**
**  Character      Column affinity
**  ------------------------------
**  'a'            TEXT
**  'b'            NONE
**  'c'            NUMERIC
**  'd'            INTEGER
**  'e'            REAL



*/
void sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){
  if( !pIdx->zColAff ){
    /* The first time a column affinity string for a particular index is
    ** required, it is allocated and populated here. It is then stored as
    ** a member of the Index structure for subsequent use.
    **
    ** The column affinity string will eventually be deleted by
    ** sqliteDeleteIndex() when the Index structure itself is cleaned
    ** up.
    */
    int n;
    Table *pTab = pIdx->pTable;
    sqlite3 *db = sqlite3VdbeDb(v);
    pIdx->zColAff = (char *)sqlite3DbMallocZero(db, pIdx->nColumn+1);
    if( !pIdx->zColAff ){
      return;
    }
    for(n=0; n<pIdx->nColumn; n++){
      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
    }

    pIdx->zColAff[pIdx->nColumn] = '\0';
  }
 
  sqlite3VdbeChangeP4(v, -1, pIdx->zColAff, 0);
}

/*
** Set P4 of the most recently inserted opcode to a column affinity

  }
  regData = regRowid+1;

  /* Run the BEFORE and INSTEAD OF triggers, if there are any
  */
  endOfLoop = sqlite3VdbeMakeLabel(v);
  if( triggers_exist & TRIGGER_BEFORE ){




    /* build the NEW.* reference row.  Note that if there is an INTEGER
    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
    ** translated into a unique ID for the row.  But on a BEFORE trigger,
    ** we do not know what the unique ID will be (because the insert has
    ** not happened yet) so we substitute a rowid of -1
    */

    if( keyColumn<0 ){
      sqlite3VdbeAddOp2(v, OP_Integer, -1, 0);
    }else if( useTempTable ){
      sqlite3VdbeAddOp2(v, OP_Column, srcTab, keyColumn);
    }else{
      int j1;
      assert( pSelect==0 );  /* Otherwise useTempTable is true */
      sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr, 0);
      sqlite3VdbeAddOp0(v, OP_SCopy);
      j1 = sqlite3VdbeAddOp0(v, OP_NotNull);
      sqlite3VdbeAddOp1(v, OP_Pop, 1);
      sqlite3VdbeAddOp1(v, OP_Integer, -1);
      sqlite3VdbeJumpHere(v, j1);
      sqlite3VdbeAddOp0(v, OP_MustBeInt);
    }

    /* Cannot have triggers on a virtual table. If it were possible,
    ** this block would have to account for hidden column.
    */
    assert(!IsVirtual(pTab));

    /* Create the new column data
    */

    for(i=0; i<pTab->nCol; i++){
      if( pColumn==0 ){
        j = i;
      }else{
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, 0);
      }else if( useTempTable ){
        sqlite3VdbeAddOp2(v, OP_Column, srcTab, j); 
      }else{
        assert( pSelect==0 ); /* Otherwise useTempTable is true */
        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr);
      }
    }

    sqlite3VdbeAddOp2(v, OP_MakeRecord, pTab->nCol, 0);

    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
    ** do not attempt any conversions before assembling the record.
    ** If this is a real table, attempt conversions as required by the
    ** table column affinities.
    */
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }

    sqlite3CodeInsert(pParse, newIdx, OPFLAG_APPEND);



    /* Fire BEFORE or INSTEAD OF triggers */
    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab, 
        newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
    }
  }

      case OE_Abort:
      case OE_Fail: {
        sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
                         "PRIMARY KEY must be unique", P4_STATIC);
        break;
      }
      case OE_Replace: {
        sqlite3GenerateRowIndexDelete(v, pTab, baseCur, 0);
        if( isUpdate ){
          sqlite3VdbeAddOp3(v, OP_MoveGe, baseCur, 0, regRowid-hasTwoRowids);
        }
        seenReplace = 1;
        break;
      }
      case OE_Ignore: {

  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Add the new records to the indices as we go.
  */
  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){



    if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */

    /* Create a key for accessing the index entry */
    sqlite3VdbeAddOp1(v, OP_SCopy, regRowid);
    for(i=0; i<pIdx->nColumn; i++){
      int idx = pIdx->aiColumn[i];
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp1(v, OP_SCopy, regRowid);
      }else{
        sqlite3VdbeAddOp1(v, OP_SCopy, regData+idx);
      }
    }

    j2 = sqlite3VdbeAddOp3(v, OP_MakeIdxRec, pIdx->nColumn, 0, aRegIdx[iCur]);
    sqlite3IndexAffinityStr(v, pIdx);


    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    if( seenReplace ){
      if( onError==OE_Ignore ) onError = OE_Replace;
      else if( onError==OE_Fail ) onError = OE_Abort;
    }
    

    /* Check to see if the new index entry will be unique */
    sqlite3VdbeAddOp1(v, OP_SCopy, aRegIdx[iCur]);

    sqlite3VdbeAddOp1(v, OP_SCopy, regRowid-hasTwoRowids);
    j3 = sqlite3VdbeAddOp4(v, OP_IsUnique, baseCur+iCur+1, 0, 0, 0, P4_INT32);


    /* Generate code that executes if the new index entry is not unique */
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
        || onError==OE_Ignore || onError==OE_Replace );
    switch( onError ){
      case OE_Rollback:
      case OE_Abort:

        sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], 
            pIdx->nColumn>1 ? " are not unique" : " is not unique");
        sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0, zErrMsg,0);
        break;
      }
      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp1(v, OP_Pop, 2+hasTwoRowids);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
        break;
      }
      case OE_Replace: {
        int iRowid = sqlite3StackToReg(pParse, 1);
        sqlite3GenerateRowDelete(pParse->db, v, pTab, baseCur, iRowid, 0);
        if( isUpdate ){
          sqlite3VdbeAddOp1(v, OP_SCopy, regRowid-hasTwoRowids);
          sqlite3VdbeAddOp2(v, OP_MoveGe, baseCur, 0);
        }
        seenReplace = 1;
        break;
      }
    }
    sqlite3VdbeJumpHere(v, j3);
    sqlite3VdbeAddOp1(v, OP_Pop, 1);
#if NULL_DISTINCT_FOR_UNIQUE
    sqlite3VdbeJumpHere(v, j2);
#endif

  }
}

/*
** This routine generates code to finish the INSERT or UPDATE operation
** that was started by a prior call to sqlite3GenerateConstraintChecks.
** A consecutive range of registers starting at regRowid contains the

/*
** 2003 April 6
**
** 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 implement the PRAGMA command.
**
** $Id: pragma.c,v 1.164 2008/01/09 23:04:12 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)

  const char *zDb = 0;   /* The database name */
  Token *pId;            /* Pointer to <id> token */
  int iDb;               /* Database index for <database> */
  sqlite3 *db = pParse->db;
  Db *pDb;
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;


  /* Interpret the [database.] part of the pragma statement. iDb is the
  ** index of the database this pragma is being applied to in db.aDb[]. */
  iDb = sqlite3TwoPartName(pParse, pId1, pId2, &pId);
  if( iDb<0 ) return;
  pDb = &db->aDb[iDb];

    assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
    if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
      zRet = "exclusive";
    }
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P4_STATIC);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, zRet, 0);
    sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
  }else
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  /*
  **  PRAGMA [database.]auto_vacuum
  **  PRAGMA [database.]auto_vacuum=N
  **

    }
    if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
      iLimit = 0x7fffffff;
    }
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
    addr = sqlite3VdbeAddOp1(v, OP_IncrVacuum, iDb);
    sqlite3VdbeAddOp0(v, OP_Callback);
    sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
    sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr);
    sqlite3VdbeJumpHere(v, addr);
  }else
#endif

#ifndef SQLITE_OMIT_PAGER_PRAGMAS

  */
  if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
    if( !zRight ){
      if( sqlite3_temp_directory ){
        sqlite3VdbeSetNumCols(v, 1);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
            "temp_store_directory", P4_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
      }
    }else{
      if( zRight[0] 
       && !sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE) 
      ){
        sqlite3ErrorMsg(pParse, "not a writable directory");
        goto pragma_out;

    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      int i;
      int nHidden = 0;
      Column *pCol;
      sqlite3VdbeSetNumCols(v, 6);

      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P4_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P4_STATIC);
      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P4_STATIC);
      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P4_STATIC);
      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P4_STATIC);
      sqlite3ViewGetColumnNames(pParse, pTab);
      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
        const Token *pDflt;
        if( IsHiddenColumn(pCol) ){
          nHidden++;
          continue;
        }
        sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 0);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pCol->zName, 0);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
           pCol->zType ? pCol->zType : "", 0);
        sqlite3VdbeAddOp2(v, OP_Integer, pCol->notNull, 0);
        if( pCol->pDflt && (pDflt = &pCol->pDflt->span)->z ){
          sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, (char*)pDflt->z, pDflt->n);
        }else{
          sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
        }
        sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 0);
        sqlite3VdbeAddOp2(v, OP_Callback, 6, 0);
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pIdx = sqlite3FindIndex(db, zRight, zDb);
    if( pIdx ){
      int i;
      pTab = pIdx->pTable;
      sqlite3VdbeSetNumCols(v, 3);

      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P4_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P4_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P4_STATIC);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
        sqlite3VdbeAddOp2(v, OP_Integer, cnum, 0);
        assert( pTab->nCol>cnum );
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->aCol[cnum].zName, 0);
        sqlite3VdbeAddOp2(v, OP_Callback, 3, 0);
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pIdx = pTab->pIndex;
      if( pIdx ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 3);

        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P4_STATIC);
        while(pIdx){
          sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
          sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pIdx->zName, 0);
          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 0);
          sqlite3VdbeAddOp2(v, OP_Callback, 3, 0);
          ++i;
          pIdx = pIdx->pNext;
        }
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "database_list")==0 ){
    int i;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 3);

    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P4_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, db->aDb[i].zName, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
      sqlite3VdbeAddOp2(v, OP_Callback, 3, 0);
    }
  }else

  if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
    int i = 0;
    HashElem *p;
    sqlite3VdbeSetNumCols(v, 2);

    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite3VdbeAddOp2(v, OP_Integer, i++, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pColl->zName, 0);
      sqlite3VdbeAddOp2(v, OP_Callback, 2, 0);
    }
  }else
#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */

#ifndef SQLITE_OMIT_FOREIGN_KEY
  if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
    FKey *pFK;
    Table *pTab;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pFK = pTab->pFKey;
      if( pFK ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 5);

        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P4_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P4_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P4_STATIC);
        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P4_STATIC);
        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P4_STATIC);
        while(pFK){
          int j;
          for(j=0; j<pFK->nCol; j++){
            char *zCol = pFK->aCol[j].zCol;
            sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
            sqlite3VdbeAddOp2(v, OP_Integer, j, 0);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pFK->zTo, 0);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
                              pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
            sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 0, 0, zCol, 0);
            sqlite3VdbeAddOp2(v, OP_Callback, 5, 0);
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }else

    int i, j, addr, mxErr;

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const VdbeOpList endCode[] = {
      { OP_SCopy,       1, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 0,        0},    /* 2 */
      { OP_String8,     0, 0,        0},    /* 3 */
      { OP_Callback,    1, 0,        0},
    };

    int isQuick = (zLeft[0]=='q');

    /* Initialize the VDBE program */
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;

    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P4_STATIC);

    /* Set the maximum error count */
    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
    if( zRight ){
      mxErr = atoi(zRight);
      if( mxErr<=0 ){
        mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
      }
    }
    sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1);
    pParse->nMem = 1;

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;
      Hash *pTbls;
      int cnt = 0;

      if( OMIT_TEMPDB && i==1 ) continue;

      sqlite3CodeVerifySchema(pParse, i);
      addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
      sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Do an integrity check of the B-Tree



      */
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 2+cnt);
        cnt++;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 2+cnt);
          cnt++;
        }
      }
      if( cnt==0 ) continue;


      if( pParse->nMem < cnt+3 ){
        pParse->nMem = cnt+3;
      }


      sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
      sqlite3VdbeChangeP5(v, i);
      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
         P4_DYNAMIC);
      sqlite3VdbeAddOp3(v, OP_Concat, 2, 3, 2);
      sqlite3VdbeAddOp2(v, OP_ResultRow, 2, 1);
      sqlite3VdbeJumpHere(v, addr);

      /* Make sure all the indices are constructed correctly.
      */
      for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
        sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
        sqlite3VdbeJumpHere(v, addr);
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp2(v, OP_Integer, 0, 2);
        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2;
          static const VdbeOpList idxErr[] = {
            { OP_AddImm,      1, -1,  0},
            { OP_String8,     0,  0,  0},    /* 1 */
            { OP_Rowid,       1,  0,  0},
            { OP_String8,     0,  0,  0},    /* 3 */
            { OP_String8,     0,  0,  0},    /* 4 */
            { OP_Concat,      0,  0,  0},
            { OP_Concat,      0,  0,  0},
            { OP_Concat,      0,  0,  0},
            { OP_Callback,    1,  0,  0},
          };
          sqlite3GenerateIndexKey(v, pIdx, 1);
          jmp2 = sqlite3VdbeAddOp2(v, OP_Found, j+2, 0);
          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
          sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC);
          sqlite3VdbeChangeP4(v, addr+3, " missing from index ", P4_STATIC);
          sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_STATIC);
          sqlite3VdbeJumpHere(v, jmp2);
        }
        sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
        sqlite3VdbeJumpHere(v, loopTop);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          static const VdbeOpList cntIdx[] = {
             { OP_Integer,      0,  3,  0},
             { OP_Rewind,       0,  0,  0},  /* 1 */
             { OP_AddImm,       3,  1,  0},
             { OP_Next,         0,  0,  0},  /* 3 */
             { OP_SCopy,        2,  0,  0},
             { OP_SCopy,        3,  0,  0},
             { OP_Eq,           0,  0,  0},  /* 6 */
             { OP_AddImm,       1, -1,  0},
             { OP_String8,      0,  0,  0},  /* 8 */
             { OP_String8,      0,  0,  0},  /* 9 */
             { OP_Concat,       0,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
          sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
          sqlite3VdbeJumpHere(v, addr);
          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
          sqlite3VdbeChangeP1(v, addr+1, j+2);
          sqlite3VdbeChangeP2(v, addr+1, addr+4);
          sqlite3VdbeChangeP1(v, addr+3, j+2);
          sqlite3VdbeChangeP2(v, addr+3, addr+2);
          sqlite3VdbeJumpHere(v, addr+6);
          sqlite3VdbeChangeP4(v, addr+8, 
                     "wrong # of entries in index ", P4_STATIC);
          sqlite3VdbeChangeP4(v, addr+9, pIdx->zName, P4_STATIC);
        }
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeChangeP1(v, addr+1, mxErr);
    sqlite3VdbeChangeP4(v, addr+3, "ok", P4_STATIC);
    sqlite3VdbeJumpHere(v, addr+2);

  }else
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"

      { 0, 0 }
    };
    const struct EncName *pEnc;
    if( !zRight ){    /* "PRAGMA encoding" */
      if( sqlite3ReadSchema(pParse) ) goto pragma_out;
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_String8, 0, 0);
      for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
        if( pEnc->enc==ENC(pParse->db) ){
          sqlite3VdbeChangeP4(v, -1, pEnc->zName, P4_STATIC);
          break;
        }
      }
      sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
    }else{                        /* "PRAGMA encoding = XXX" */
      /* Only change the value of sqlite.enc if the database handle is not
      ** initialized. If the main database exists, the new sqlite.enc value
      ** will be overwritten when the schema is next loaded. If it does not
      ** already exists, it will be created to use the new encoding value.
      */
      if( 

      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+1, atoi(zRight));
      sqlite3VdbeChangeP1(v, addr+2, iDb);
      sqlite3VdbeChangeP2(v, addr+2, iCookie);
    }else{
      /* Read the specified cookie value */
      static const VdbeOpList readCookie[] = {
        { OP_ReadCookie,      0,  0,  0},    /* 0 */
        { OP_Callback,        1,  0,  0}
      };
      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP3(v, addr, iCookie);
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, P4_TRANSIENT);
    }

  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
    static const char *const azLockName[] = {
      "unlocked", "shared", "reserved", "pending", "exclusive"
    };
    int i;
    Vdbe *v = sqlite3GetVdbe(pParse);
    sqlite3VdbeSetNumCols(v, 2);

    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P4_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P4_STATIC);
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      Pager *pPager;
      const char *zState = "unknown";
      int j;
      if( db->aDb[i].zName==0 ) continue;
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, db->aDb[i].zName, P4_STATIC);
      pBt = db->aDb[i].pBt;
      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
        zState = "closed";
      }else if( sqlite3_file_control(db, db->aDb[i].zName, 
                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
         zState = azLockName[j];
      }
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, zState, P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_Callback, 2, 0);
    }
  }else
#endif

#ifdef SQLITE_SSE
  /*
  ** Check to see if the sqlite_statements table exists.  Create it

**    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 1.396 2008/01/10 03:46:36 drh Exp $
*/
#include "sqliteInt.h"


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

  int iTab;
  int pseudoTab = 0;
  ExprList *pOrderBy = p->pOrderBy;

  int eDest = pDest->eDest;
  int iParm = pDest->iParm;




  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, 0);
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    sqlite3VdbeAddOp2(v, OP_Integer, 1, 0);
  }
  sqlite3VdbeAddOp2(v, OP_Column, iTab, pOrderBy->nExpr + 1);
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp1(v, OP_NewRowid, iParm);
      sqlite3VdbeAddOp2(v, OP_Pull, 1, 0);

      sqlite3CodeInsert(pParse, iParm, OPFLAG_APPEND);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      int j1, j2;
      assert( nColumn==1 );
      sqlite3VdbeAddOp0(v, OP_SCopy);
      j1 = sqlite3VdbeAddOp0(v, OP_NotNull);
      sqlite3VdbeAddOp1(v, OP_Pop, 1);
      j2 = sqlite3VdbeAddOp0(v, OP_Goto);
      sqlite3VdbeJumpHere(v, j1);
      sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &p->affinity, 1);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, 0);
      sqlite3VdbeJumpHere(v, j2);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp2(v, OP_Move, 0, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }
#endif
    case SRT_Callback:
    case SRT_Subroutine: {
      int i;
      sqlite3CodeInsert(pParse, pseudoTab, 0);

      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp3(v, OP_Column, pseudoTab, i, pDest->iMem+i);
      }
      if( eDest==SRT_Callback ){
        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iMem, nColumn);
      }else{
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }
      break;
    }
    default: {
      /* Do nothing */
      break;
    }
  }



  /* Jump to the end of the loop when the LIMIT is reached
  */
  if( p->iLimit>=0 ){
    sqlite3VdbeAddOp2(v, OP_AddImm, p->iLimit, -1);
    sqlite3VdbeAddOp2(v, OP_IfZero, p->iLimit, brk);
  }

    return ORDERBY_MIN;
  }else if( sqlite3StrNICmp((char*)pExpr->token.z,"max",3)==0 ){
    return ORDERBY_MAX;
  }
  return ORDERBY_NORMAL;
}

/*
** Analyze the SELECT statement passed in as an argument to see if it
** is a simple min() or max() query.  If it is and this query can be
** satisfied using a single seek to the beginning or end of an index,
** then generate the code for this SELECT and return 1.  If this is not a 
** simple min() or max() query, then return 0;
**
** A simply min() or max() query looks like this:
**
**    SELECT min(a) FROM table;
**    SELECT max(a) FROM table;
**
** The query may have only a single table in its FROM argument.  There
** can be no GROUP BY or HAVING or WHERE clauses.  The result set must
** be the min() or max() of a single column of the table.  The column
** in the min() or max() function must be indexed.
**
** The parameters to this routine are the same as for sqlite3Select().
** See the header comment on that routine for additional information.
*/
#if 0
static int simpleMinMaxQuery(Parse *pParse, Select *p, SelectDest *pDest){
  Expr *pExpr;
  int iCol;
  Table *pTab;
  Index *pIdx;
  int base;
  Vdbe *v;
  int seekOp;
  ExprList *pEList, *pList, eList;
  struct ExprList_item eListItem;
  SrcList *pSrc;
  int brk;
  int iDb;

  /* Check to see if this query is a simple min() or max() query.  Return
  ** zero if it is  not.
  */
  if( p->pGroupBy || p->pHaving || p->pWhere ) return 0;
  pSrc = p->pSrc;
  if( pSrc->nSrc!=1 ) return 0;
  pEList = p->pEList;
  if( pEList->nExpr!=1 ) return 0;
  pExpr = pEList->a[0].pExpr;
  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
  pList = pExpr->pList;
  if( pList==0 || pList->nExpr!=1 ) return 0;
  if( pExpr->token.n!=3 ) return 0;
  if( sqlite3StrNICmp((char*)pExpr->token.z,"min",3)==0 ){
    seekOp = OP_Rewind;
  }else if( sqlite3StrNICmp((char*)pExpr->token.z,"max",3)==0 ){
    seekOp = OP_Last;
  }else{
    return 0;
  }
  pExpr = pList->a[0].pExpr;
  if( pExpr->op!=TK_COLUMN ) return 0;
  iCol = pExpr->iColumn;
  pTab = pSrc->a[0].pTab;

  /* This optimization cannot be used with virtual tables. */
  if( IsVirtual(pTab) ) return 0;

  /* If we get to here, it means the query is of the correct form.
  ** Check to make sure we have an index and make pIdx point to the
  ** appropriate index.  If the min() or max() is on an INTEGER PRIMARY
  ** key column, no index is necessary so set pIdx to NULL.  If no
  ** usable index is found, return 0.
  */
  if( iCol<0 ){
    pIdx = 0;
  }else{
    CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr);
    if( pColl==0 ) return 0;
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      assert( pIdx->nColumn>=1 );
      if( pIdx->aiColumn[0]==iCol && 
          0==sqlite3StrICmp(pIdx->azColl[0], pColl->zName) ){
        break;
      }
    }
    if( pIdx==0 ) return 0;
  }

  /* Identify column types if we will be using the callback.  This
  ** step is skipped if the output is going to a table or a memory cell.
  ** The column names have already been generated in the calling function.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return 0;

  /* If the output is destined for a temporary table, open that table.
  */
  if( pDest->eDest==SRT_EphemTab ){
    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iParm, 1);
  }

  /* Generating code to find the min or the max.  Basically all we have
  ** to do is find the first or the last entry in the chosen index.  If
  ** the min() or max() is on the INTEGER PRIMARY KEY, then find the first
  ** or last entry in the main table.
  */
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  assert( iDb>=0 || pTab->isEphem );
  sqlite3CodeVerifySchema(pParse, iDb);
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
  base = pSrc->a[0].iCursor;
  brk = sqlite3VdbeMakeLabel(v);
  computeLimitRegisters(pParse, p, brk);
  if( pSrc->a[0].pSelect==0 ){
    sqlite3OpenTable(pParse, base, iDb, pTab, OP_OpenRead);
  }
  if( pIdx==0 ){
    sqlite3VdbeAddOp2(v, seekOp, base, 0);
  }else{
    /* Even though the cursor used to open the index here is closed
    ** as soon as a single value has been read from it, allocate it
    ** using (pParse->nTab++) to prevent the cursor id from being 
    ** reused. This is important for statements of the form 
    ** "INSERT INTO x SELECT max() FROM x".
    */
    int iIdx;
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    iIdx = pParse->nTab++;
    assert( pIdx->pSchema==pTab->pSchema );
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdx, pIdx->tnum, iDb,
        (char*)pKey, P4_KEYINFO_HANDOFF);
    if( seekOp==OP_Rewind ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
      sqlite3VdbeAddOp2(v, OP_MakeRecord, 1, 0);
      seekOp = OP_MoveGt;
    }
    if( pIdx->aSortOrder[0]==SQLITE_SO_DESC ){
      /* Ticket #2514: invert the seek operator if we are using
      ** a descending index. */
      if( seekOp==OP_Last ){
        seekOp = OP_Rewind;
      }else{
        assert( seekOp==OP_MoveGt );
        seekOp = OP_MoveLt;
      }
    }
    sqlite3VdbeAddOp2(v, seekOp, iIdx, 0);
    sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdx, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iIdx, 0);
    sqlite3VdbeAddOp2(v, OP_MoveGe, 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, pDest, brk, brk, 0);
  sqlite3VdbeResolveLabel(v, brk);
  sqlite3VdbeAddOp2(v, OP_Close, base, 0);
  
  return 1;
}
#endif 

/*
** This routine resolves any names used in the result set of the
** supplied SELECT statement. If the SELECT statement being resolved
** is a sub-select, then pOuterNC is a pointer to the NameContext 
** of the parent SELECT.
*/
int sqlite3SelectResolve(

/*
** 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 1.646 2008/01/10 03:46:36 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

void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
void sqlite3WhereEnd(WhereInfo*);
void sqlite3ExprCodeGetColumn(Vdbe*, Table*, int, int, int);
int sqlite3ExprCode(Parse*, Expr*, int);
void sqlite3ExprCodeAndCache(Parse*, Expr*);
int sqlite3ExprCodeExprList(Parse*, ExprList*, int);
void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
Table *sqlite3FindTable(sqlite3*,const char*, const char*);
Table *sqlite3LocateTable(Parse*,const char*, const char*);
Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);

void sqlite3CommitTransaction(Parse*);
void sqlite3RollbackTransaction(Parse*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(sqlite3*, Vdbe*, Table*, int, int, int);
void sqlite3GenerateRowIndexDelete(Vdbe*, Table*, int, int*);
void sqlite3GenerateIndexKey(Vdbe*, Index*, int);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
                                     int*,int,int,int,int);
void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*,int,int,int,int);
int sqlite3OpenTableAndIndices(Parse*, Table*, int, int);
void sqlite3BeginWriteOperation(Parse*, int, int);
Expr *sqlite3ExprDup(sqlite3*,Expr*);
void sqlite3TokenCopy(sqlite3*,Token*, Token*);

    goto triggerfinish_cleanup;
  }

  /* if we are not initializing, and this trigger is not on a TEMP table, 
  ** build the sqlite_master entry
  */
  if( !db->init.busy ){
    static const VdbeOpList insertTrig[] = {
      { OP_NewRowid,   0, 0,  0          },
      { OP_String8,    0, 0,  0          },  /* 1: "trigger" */
      { OP_String8,    0, 0,  0          },  /* 2: trigger name */
      { OP_String8,    0, 0,  0          },  /* 3: table name */
      { OP_Integer,    0, 0,  0          },
      { OP_String8,    0, 0,  0          },  /* 5: "CREATE TRIGGER " */
      { OP_String8,    0, 0,  0          },  /* 6: SQL */
      { OP_Concat,     0, 0,  0          }, 
      { OP_MakeRecord, 5, 0,  0          },  /* 8: "aaada" */
      { OP_Move,       0, 0,  0          },  /* 9: Store data */
      { OP_Move,       0, 0,  0          },  /* 10: Store key */
      { OP_Insert,     0, 0,  0          },
    };
    int addr;
    Vdbe *v;
    int iKey = ++pParse->nMem;
    int iData = ++pParse->nMem;

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
    sqlite3VdbeChangeP4(v, addr+1, "trigger", P4_STATIC);
    sqlite3VdbeChangeP4(v, addr+2, pTrig->name, 0); 
    sqlite3VdbeChangeP4(v, addr+3, pTrig->table, 0);
    sqlite3VdbeChangeP4(v, addr+5, "CREATE TRIGGER ", P4_STATIC); 
    sqlite3VdbeChangeP4(v, addr+6, (char*)pAll->z, pAll->n);
    sqlite3VdbeChangeP4(v, addr+8, "aaada", P4_STATIC);
    sqlite3VdbeChangeP2(v, addr+9, iData);
    sqlite3VdbeChangeP2(v, addr+10, iKey);
    sqlite3VdbeChangeP2(v, addr+11, iData);
    sqlite3VdbeChangeP3(v, addr+11, iKey);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, sqlite3MPrintf(
        db, "type='trigger' AND name='%q'", pTrig->name), P4_DYNAMIC
    );
  }

  if( db->init.busy ){
    int n;

**    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 1.166 2008/01/09 23:04:12 drh Exp $
*/
#include "sqliteInt.h"

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

  }

  /* Top of the update loop */
  addr = sqlite3VdbeAddOp2(v, OP_FifoRead, regOldRowid, 0);
  sqlite3VdbeAddOp2(v, OP_StackDepth, -1, 0);

  if( triggers_exist ){




    /* Make cursor iCur point to the record that is being updated.
    */
    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addr, regOldRowid);

    /* Generate the OLD table
    */


    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
    if( !old_col_mask ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
    }else{
      sqlite3VdbeAddOp1(v, OP_RowData, iCur);
    }
    sqlite3CodeInsert(pParse, oldIdx, 0);

    /* Generate the NEW table
    */
    if( chngRowid ){
      sqlite3ExprCodeAndCache(pParse, pRowidExpr);
    }else{
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
    }

    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
        continue;
      }
      j = aXRef[i];
      if( new_col_mask&((u32)1<<i) || new_col_mask==0xffffffff ){
        if( j<0 ){
          sqlite3VdbeAddOp2(v, OP_Column, iCur, i);
          sqlite3ColumnDefault(v, pTab, i);
        }else{
          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
        }
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
      }
    }
    sqlite3VdbeAddOp2(v, OP_MakeRecord, pTab->nCol, 0);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }

    if( pParse->nErr ) goto update_cleanup;


    sqlite3CodeInsert(pParse, newIdx, 0);

    sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
    sqlite3VdbeJumpHere(v, iEndBeforeTrigger);
  }

  if( !isView && !IsVirtual(pTab) ){
    /* Loop over every record that needs updating.  We have to load

    */
    sqlite3GenerateConstraintChecks(pParse, pTab, iCur, regNewRowid,
                                    aRegIdx, chngRowid, 1,
                                    onError, addr);

    /* Delete the old indices for the current record.
    */
    sqlite3GenerateRowIndexDelete(v, pTab, iCur, aRegIdx);

    /* If changing the record number, delete the old record.
    */
    if( chngRowid ){
      sqlite3VdbeAddOp2(v, OP_Delete, iCur, 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 1.691 2008/01/09 23:04:12 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

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

  if( pOp->p2==0 ){
    pOut = ++pTos;
    pOut->flags = MEM_Null;
  }else{
    assert( pOp->p2<=p->nMem );
    pOut = &p->aMem[pOp->p2];
  }

  if( pOp->opcode==OP_Move ){
    rc = sqlite3VdbeMemMove(pOut, pIn1);
    if( pOp->p1==0 ) pTos--;
  }else{

    sqlite3VdbeMemShallowCopy(pOut, pIn1, MEM_Ephem);
    if( pOp->opcode==OP_Copy ){
      Deephemeralize(pOut);
    }
  }
  REGISTER_TRACE(pOp->p2, pOut);
  break;

    assert( pTos->flags & (MEM_Str|MEM_Blob) );
    assert( pTos->z==pTos[-pOp->p1].zShort );
    pTos->z = pTos->zShort;
  }
  break;
}

/* Opcode: Callback P1 * *
**
** The top P1 values on the stack represent a single result row from
** a query.  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
** values will be automatically popped from the stack before the next
** instruction executes.
*/
case OP_Callback: {            /* no-push */
  Mem *pMem;
  Mem *pFirstColumn;
  assert( p->nResColumn==pOp->p1 );

  /* Data in the pager might be moved or changed out from under us
  ** in between the return from this sqlite3_step() call and the
  ** next call to sqlite3_step().  So deephermeralize everything on 
  ** the stack.  Note that ephemeral data is never stored in memory 
  ** cells so we do not have to worry about them.
  */
  pFirstColumn = &pTos[1-pOp->p1];
  for(pMem = p->aStack; pMem<pFirstColumn; pMem++){
    Deephemeralize(pMem);
  }

  /* Invalidate all ephemeral cursor row caches */
  p->cacheCtr = (p->cacheCtr + 2)|1;

  /* Make sure the results of the current row are \000 terminated
  ** and have an assigned type.  The results are deephemeralized as
  ** as side effect.
  */
  for(; pMem<=pTos; pMem++ ){
    sqlite3VdbeMemNulTerminate(pMem);
    storeTypeInfo(pMem, encoding);
  }

  /* Set up the statement structure so that it will pop the current
  ** results from the stack when the statement returns.
  */
  p->pResultSet = pFirstColumn;
  p->nCallback++;
  p->popStack = pOp->p1;
  p->pc = pc + 1;
  p->pTos = pTos;
  rc = SQLITE_ROW;
  goto vdbe_return;
}

/* 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

** with its complement.  If the value in register P1 is NULL its value
** is unchanged.
*/
case OP_Not: {                /* same as TK_NOT, no-push, in1 */
  nPop = 0;
  if( pIn1->flags & MEM_Null ) break;  /* Do nothing to NULLs */
  sqlite3VdbeMemIntegerify(pIn1);
  assert( (pIn1->flags & MEM_Dyn)==0 );
  pIn1->u.i = !pIn1->u.i;
  pIn1->flags = MEM_Int;
  break;
}

/* Opcode: BitNot P1 * * * *
**
** Interpret the content of register P1 as an integer.  Replace it
** with its ones-complement.  If the value is originally NULL, leave
** it unchanged.
*/
case OP_BitNot: {             /* same as TK_BITNOT, no-push, in1 */
  nPop = 0;
  if( pIn1->flags & MEM_Null ) break;  /* Do nothing to NULLs */
  sqlite3VdbeMemIntegerify(pIn1);
  assert( (pIn1->flags & MEM_Dyn)==0 );
  pIn1->u.i = ~pIn1->u.i;
  pIn1->flags = MEM_Int;
  break;
}

/* Opcode: Noop * * * * *
**
** Do nothing.  This instruction is often useful as a jump
** destination.

  }
  if( pOp->p1>0 ){
    popStack(&pTos, pOp->p1);
  }
  break;
}

/* Opcode: IsNull P1 P2 * * *
**
** Jump to P2 if the value in register P1 is NULL.


**
** If P1 is 0 then use the top of the stack instead of a register
** and pop the stack regardless of whether or not the jump is taken.
*/
case OP_IsNull: {            /* same as TK_ISNULL, no-push, jump, in1 */



  if( (pIn1->flags & MEM_Null)!=0 ){
    pc = pOp->p2 - 1;

  }


  break;
}

/* Opcode: NotNull P1 P2 * * *
**
** Jump to P2 if the value in register P1 is not NULL.  
**

** field of the index key (i.e. the first character of P4 corresponds to the
** lowest element on the stack).
**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P4 is NULL then all index fields have the affinity NONE.
**
** See also OP_MakeIdxRec
*/
/* Opcode: MakeIdxRec P1 P2 P4
**
** This opcode works just OP_MakeRecord except that it reads an extra
** integer from the stack (thus reading a total of abs(P1+1) entries)
** and appends that extra integer to the end of the record as a varint.
** This results in an index key.
*/
/*
** Opcode: RegMakeRec P1 P2 P3 P4 *
**
** Builds a record like OP_MakeRecord.  But the data is taken from
** P2 registers beginning with P1:  P1, P1+1, P1+2, ..., P1+P2-1.
** The result is written into P3 or pushed onto the stack if P3 is zero.
** There is no jump on NULL - that can be done with a separate
** OP_AnyNull opcode.
*/
/*
** Opcode: RegMakeIRec P1 P2 P4
**
** Works like OP_MakeIdxRec except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
case OP_RegMakeRec:
case OP_RegMakeIRec:
case OP_MakeIdxRec:          /* jump */
case OP_MakeRecord: {        /* jump */
  /* Assuming the record contains N fields, the record format looks
  ** like this:
  **
  ** ------------------------------------------------------------------------
  ** | hdr-size | type 0 | type 1 | ... | type N-1 | data0 | ... | data N-1 | 
  ** ------------------------------------------------------------------------
  **
  ** Data(0) is taken from the lowest element of the stack and data(N-1) is
  ** the top of the stack.
  **
  ** Each type field is a varint representing the serial type of the 
  ** corresponding data element (see sqlite3VdbeSerialType()). The
  ** hdr-size field is also a varint which is the offset from the beginning
  ** of the record to data0.
  */
  u8 *zNewRecord;        /* A buffer to hold the data for the new record */
  Mem *pRec;             /* The new record */
  Mem *pRowid = 0;       /* Rowid appended to the new record */
  u64 nData = 0;         /* Number of bytes of data space */
  int nHdr = 0;          /* Number of bytes of header space */
  u64 nByte = 0;         /* Data space required for this record */
  int nZero = 0;         /* Number of zero bytes at the end of the record */
  int nVarint;           /* Number of bytes in a varint */
  u32 serial_type;       /* Type field */
  int containsNull = 0;  /* True if any of the data fields are NULL */
  Mem *pData0;           /* Bottom of the stack */
  Mem *pLast;            /* Top of the stack */
  int leaveOnStack;      /* If true, leave the entries on the stack */
  int nField;            /* Number of fields in the record */
  int jumpIfNull;        /* Jump here if non-zero and any entries are NULL. */
  int addRowid;          /* True to append a rowid column at the end */
  char *zAffinity;       /* The affinity string for the record */
  int file_format;       /* File format to use for encoding */
  int i;                 /* Space used in zNewRecord[] */
  char zTemp[NBFS];      /* Space to hold small records */

  if( pOp->p1<0 ){
    assert( pOp->opcode==OP_MakeRecord || pOp->opcode==OP_MakeIdxRec );
    leaveOnStack = 1;
    nField = -pOp->p1;
  }else{
    leaveOnStack = 0;
    nField = pOp->p1;
  }
  addRowid = pOp->opcode==OP_MakeIdxRec || pOp->opcode==OP_RegMakeIRec;
  zAffinity = pOp->p4.z;

  if( pOp->opcode==OP_RegMakeRec || pOp->opcode==OP_RegMakeIRec ){
    assert( nField>0 && pOp->p2>0 && pOp->p2+nField<=p->nMem );
    pData0 = &p->aMem[nField];
    nField = pOp->p2;
    leaveOnStack = 1;
    jumpIfNull = 0;
    pLast = &pData0[nField-1];
  }else{

      ** We do not allow blobs with a prefix and a zero-filled tail. */
      nZero += pRec->u.i;
    }else if( len ){
      nZero = 0;
    }
  }

  /* If we have to append a varint rowid to this record, set pRowid
  ** to the value of the rowid and increase nByte by the amount of space
  ** required to store it.
  */
  if( addRowid ){
    pRowid = &pData0[-1];
    assert( pRowid>=p->aStack );
    sqlite3VdbeMemIntegerify(pRowid);
    serial_type = sqlite3VdbeSerialType(pRowid, 0);
    nData += sqlite3VdbeSerialTypeLen(serial_type);
    nHdr += sqlite3VarintLen(serial_type);
    nZero = 0;
  }

  /* Add the initial header varint and total the size */
  nHdr += nVarint = sqlite3VarintLen(nHdr);
  if( nVarint<sqlite3VarintLen(nHdr) ){
    nHdr++;
  }
  nByte = nHdr+nData-nZero;
  if( nByte>SQLITE_MAX_LENGTH ){

  /* Write the record */
  i = sqlite3PutVarint(zNewRecord, nHdr);
  for(pRec=pData0; pRec<=pLast; pRec++){
    serial_type = sqlite3VdbeSerialType(pRec, file_format);
    i += sqlite3PutVarint(&zNewRecord[i], serial_type);      /* serial type */
  }
  if( addRowid ){
    i += sqlite3PutVarint(&zNewRecord[i], sqlite3VdbeSerialType(pRowid, 0));
  }
  for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
    i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRec, file_format);
  }
  if( addRowid ){
    i += sqlite3VdbeSerialPut(&zNewRecord[i], nByte-i, pRowid, 0);
  }
  assert( i==nByte );

  /* Pop entries off the stack if required. Push the new record on. */
  if( !leaveOnStack ){
    popStack(&pTos, nField+addRowid);
  }
  if( pOp->p3==0 ){
    pOut = ++pTos;
  }else{
    pOut = &p->aMem[pOp->p3];
    Release(pOut);
  }

    /* The final varint of the key is different from R.  Push it onto
    ** the stack.  (The record number of an entry that violates a UNIQUE
    ** constraint.)
    */
    nPop = 0;
    pIn3->u.i = v;
    pIn3->flags = MEM_Int;
  }
  break;
}

/* Opcode: NotExists P1 P2 P3
**
** Use the top of the stack as a integer key. Or, if P3 is non-zero,

}

/*
** Change the value of the P2 operand for a specific instruction.
** This routine is useful for setting a jump destination.
*/
void sqlite3VdbeChangeP2(Vdbe *p, int addr, int val){
  assert( val>=0 );
  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
  if( p && addr>=0 && p->nOp>addr && p->aOp ){
    p->aOp[addr].p2 = val;
  }
}

/*

**    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 incremental BLOB I/O.
**
** $Id: vdbeblob.c,v 1.17 2008/01/03 07:54:24 danielk1977 Exp $
*/

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_INCRBLOB

  /* This VDBE program seeks a btree cursor to the identified 
  ** db/table/row entry. The reason for using a vdbe program instead
  ** of writing code to use the b-tree layer directly is that the
  ** vdbe program will take advantage of the various transaction,
  ** locking and error handling infrastructure built into the vdbe.
  **
  ** After seeking the cursor, the vdbe executes an OP_Callback.
  ** Code external to the Vdbe then "borrows" the b-tree cursor and
  ** uses it to implement the blob_read(), blob_write() and 
  ** blob_bytes() functions.
  **
  ** The sqlite3_blob_close() function finalizes the vdbe program,
  ** which closes the b-tree cursor and (possibly) commits the 
  ** transaction.
  */
  static const VdbeOpList openBlob[] = {
    {OP_Transaction, 0, 0, 0},     /* 0: Start a transaction */
    {OP_VerifyCookie, 0, 0, 0},    /* 1: Check the schema cookie */

    /* One of the following two instructions is replaced by an
    ** OP_Noop before exection.
    */
    {OP_OpenRead, 0, 0, 0},        /* 2: Open cursor 0 for reading */
    {OP_OpenWrite, 0, 0, 0},       /* 3: Open cursor 0 for read/write */
    {OP_SetNumColumns, 0, 0, 0},   /* 4: Num cols for cursor */

    {OP_Variable, 1, 0, 0},        /* 5: Push the rowid to the stack */
    {OP_NotExists, 0, 10, 0},      /* 6: Seek the cursor */
    {OP_Column, 0, 0, 0},          /* 7  */
    {OP_Callback, 0, 0, 0},        /* 8  */
    {OP_Close, 0, 0, 0},           /* 9  */
    {OP_Halt, 0, 0, 0},            /* 10 */
  };

  Vdbe *v = 0;
  int rc = SQLITE_OK;
  char zErr[128];

      ** does. An OP_Column to retrieve this imaginary column will
      ** always return an SQL NULL. This is useful because it means
      ** we can invoke OP_Column to fill in the vdbe cursors type 
      ** and offset cache without causing any IO.
      */
      sqlite3VdbeChangeP2(v, 4, pTab->nCol+1);
      if( !db->mallocFailed ){
        sqlite3VdbeMakeReady(v, 1, 0, 1, 0);
      }
    }
   
    sqlite3BtreeLeaveAll(db);
    rc = sqlite3SafetyOff(db);
    if( rc!=SQLITE_OK || db->mallocFailed ){
      goto blob_open_out;