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 1.175 2004/12/07 15:41:49 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

         sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
         VdbeComment((v, "# raise(IGNORE)"));
      }
    }
    break;
  }
}

/*
** Generate code that evalutes the given expression and leaves the result
** on the stack.  See also sqlite3ExprCode().
**
** 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;
  int iMem;
  int addr1, addr2;
  if( v==0 ) return;
  addr1 = sqlite3VdbeCurrentAddr(v);
  sqlite3ExprCode(pParse, pExpr);
  addr2 = sqlite3VdbeCurrentAddr(v);
  if( addr2>addr1+1 || sqlite3VdbeGetOp(v, addr1)->opcode==OP_Function ){
    iMem = pExpr->iTable = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);
    pExpr->op = TK_REGISTER;
  }
}

/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
** Return the number of elements pushed onto the stack.
*/

**    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 1.128 2004/12/07 15:41:49 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:

      if( pColumn && j>=pColumn->nId ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
      }else if( useTempTable ){
        sqlite3VdbeAddOp(v, OP_Column, srcTab, j); 
      }else if( pSelect ){
        sqlite3VdbeAddOp(v, OP_Dup, nColumn-j-1, 1);
      }else{
        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr);
      }
    }
    sqlite3VdbeAddOp(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

/*
** 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 1.346 2004/12/07 15:41:49 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks

void sqlite3OpenTableForReading(Vdbe*, int iCur, Table*);
void sqlite3OpenTable(Vdbe*, int iCur, Table*, int);
void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, int, ExprList**, Fetch*);
void sqlite3WhereEnd(WhereInfo*);
void sqlite3ExprCode(Parse*, Expr*);
void sqlite3ExprCodeAndCache(Parse*, Expr*);
int sqlite3ExprCodeExprList(Parse*, ExprList*);
void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
void sqlite3NextedParse(Parse*, const char*, ...);
Table *sqlite3FindTable(sqlite3*,const char*, const char*);
Table *sqlite3LocateTable(Parse*,const char*, const char*);
Index *sqlite3FindIndex(sqlite3*,const char*, const char*);

**    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 1.99 2004/12/07 15:41:49 drh Exp $
*/
#include "sqliteInt.h"

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

    sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
    sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
    sqlite3VdbeAddOp(v, OP_PutIntKey, oldIdx, 0);

    /* Generate the NEW table
    */
    if( chngRecno ){
      sqlite3ExprCodeAndCache(pParse, pRecnoExpr);
    }else{
      sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
    }
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp(v, OP_String8, 0, 0);
        continue;
      }
      j = aXRef[i];
      if( j<0 ){
        sqlite3VdbeAddOp(v, OP_Column, iCur, i);
      }else{
        sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
      }
    }
    sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    if( pParse->nErr ) goto update_cleanup;

# 2004 December 07
#
# 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.
#
# This file implements tests to make sure expression of an INSERT
# and UPDATE statement are only evaluated once.  See ticket #980.
# If an expression uses a function that has side-effects or which
# is not deterministic (ex: random()) then we want to make sure
# that the same evaluation occurs for the actual INSERT/UPDATE and
# for the NEW.* fields of any triggers that fire.
#
# $Id: trigger6.test,v 1.1 2004/12/07 15:41:50 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
ifcapable {!trigger} {
  finish_test
  return
}

do_test trigger6-1.1 {
  execsql {
    CREATE TABLE t1(x, y);
    CREATE TABLE log(a, b, c);
    CREATE TRIGGER r1 BEFORE INSERT ON t1 BEGIN
      INSERT INTO log VALUES(1, new.x, new.y);
    END;
    CREATE TRIGGER r2 BEFORE UPDATE ON t1 BEGIN
      INSERT INTO log VALUES(2, new.x, new.y);
    END;
  }
  set ::trigger6_cnt 0
  proc trigger6_counter {args} {
    incr ::trigger6_cnt
    return $::trigger6_cnt
  }
  db function counter trigger6_counter
  execsql {
    INSERT INTO t1 VALUES(1,counter());
    SELECT * FROM t1;
  }
} {1 1}
do_test trigger6-1.2 {
  execsql {
    SELECT * FROM log;
  }
} {1 1 1}
do_test trigger6-1.3 {
  execsql {
    DELETE FROM t1;
    DELETE FROM log;
    INSERT INTO t1 VALUES(2,counter(2,3)+4);
    SELECT * FROM t1;
  }
} {2 6.0}
do_test trigger6-1.4 {
  execsql {
    SELECT * FROM log;
  }
} {1 2 6.0}
do_test trigger6-1.5 {
  execsql {
    DELETE FROM log;
    UPDATE t1 SET y=counter(5);
    SELECT * FROM t1;
  }
} {2 3}
do_test trigger6-1.6 {
  execsql {
    SELECT * FROM log;
  }
} {2 2 3}

finish_test