SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.49 2002/02/28 00:41:10 drh Exp $
*/
#include "sqliteInt.h"


/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqliteMalloc().  The calling function

      }
      if( i>=pParse->nAgg ){
        i = appendAggInfo(pParse);
        if( i<0 ) return 1;
        pParse->aAgg[i].isAgg = 1;
        pParse->aAgg[i].pExpr = pExpr;
        pParse->aAgg[i].pFunc = sqliteFindFunction(pParse->db,
             pExpr->token.z, pExpr->token.n, pExpr->pList->nExpr, 0);

      }
      pExpr->iAgg = i;
      break;
    }
    default: {
      if( pExpr->pLeft ){
        nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pLeft);

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.7 2002/02/28 00:46:26 drh Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"

  if( (argc==0 || argv[0]) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite_func *context){
  CountCtx *p;
  p = sqlite_aggregate_context(context, sizeof(*p));
  if( p ){
    sqlite_set_result_int(context, p->n);
  }
}

/*
** This function tracks state information for the min() and max()
** aggregate functions.
*/
typedef struct MinMaxCtx MinMaxCtx;

**    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 1.69 2002/02/28 00:41:11 drh Exp $
*/
#include "sqliteInt.h"

/*
** Allocate a new Select structure and return a pointer to that
** structure.
*/

      assert( pE->op==TK_AGG_FUNCTION );
      if( pE->pList ){
        for(j=0; j<pE->pList->nExpr; j++){
          sqliteExprCode(pParse, pE->pList->a[j].pExpr);
        }
      }
      sqliteVdbeAddOp(v, OP_Integer, i, 0);
      sqliteVdbeAddOp(v, OP_AggFunc, 0, pE->pList->nExpr);
      assert( pParse->aAgg[i].pFunc!=0 );
      assert( pParse->aAgg[i].pFunc->xStep!=0 );
      sqliteVdbeChangeP3(v, -1, (char*)pParse->aAgg[i].pFunc, P3_POINTER);
    }
  }

  /* End the database scan loop.

** type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.126 2002/02/28 00:41:11 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

*/
case OP_AggFunc: {
  int n = pOp->p2;
  int i;
  Mem *pMem;
  sqlite_func ctx;

  VERIFY( if( n<=0 ) goto bad_instruction; )
  VERIFY( if( p->tos+1<n ) goto not_enough_stack; )
  VERIFY( if( aStack[p->tos].flags!=STK_Int ) goto bad_instruction; )
  for(i=p->tos-n; i<p->tos; i++){
    if( (aStack[i].flags & STK_Null)==0 ){
      if( Stringify(p, i) ) goto no_mem;
    }
  }

    int nErr = 0;
    p->agg.pCurrent = sqliteHashData(p->agg.pSearch);
    aMem = p->agg.pCurrent->aMem;
    for(i=0; i<p->agg.nMem; i++){
      int freeCtx;
      if( p->agg.apFunc[i]==0 ) continue;
      if( p->agg.apFunc[i]->xFinalize==0 ) continue;
      if( (aMem[i].s.flags & STK_AggCtx)==0 ) continue;
      ctx.s.flags = STK_Null;
      ctx.z = 0;
      ctx.pAgg = (void*)aMem[i].z;
      freeCtx = aMem[i].z && aMem[i].z!=aMem[i].s.z;
      ctx.cnt = aMem[i].s.i;
      ctx.isStep = 0;
      ctx.pFunc = p->agg.apFunc[i];