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 1.76 2002/06/29 02:20:08 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

  }
  return 0;
}

/*
** Return TRUE if the given string is a row-id column name.
*/
int sqliteIsRowid(const char *z){
  if( sqliteStrICmp(z, "_ROWID_")==0 ) return 1;
  if( sqliteStrICmp(z, "ROWID")==0 ) return 1;
  if( sqliteStrICmp(z, "OID")==0 ) return 1;
  return 0;
}

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.102 2002/06/29 02:20:08 drh Exp $
*/
#include "sqliteInt.h"

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

    }

    /* 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 lbl = sqliteVdbeMakeLabel(v);
      assert( nColumn==1 );
      sqliteVdbeAddOp(v, OP_IsNull, -1, lbl);

      if( pOrderBy ){
        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeAddOp(v, OP_PutStrKey, iParm, 0);
      }
      sqliteVdbeResolveLabel(v, lbl);
      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.
    */

/*
** 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 1.133 2002/06/29 02:20:09 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>

int sqliteRandomInteger(void);
void sqliteBeginTransaction(Parse*, int);
void sqliteCommitTransaction(Parse*);
void sqliteRollbackTransaction(Parse*);
char *sqlite_mprintf(const char *, ...);
int sqliteExprIsConstant(Expr*);
int sqliteExprIsInteger(Expr*, int*);
int sqliteIsRowid(const char*);
void sqliteGenerateRowDelete(Vdbe*, Table*, int, int);
void sqliteGenerateRowIndexDelete(Vdbe*, Table*, int, char*);
void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int);
void sqliteBeginWriteOperation(Parse*, int);
void sqliteEndWriteOperation(Parse*);
void sqliteExprMoveStrings(Expr*, int);

**    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 1.46 2002/06/29 02:20:09 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(

  sqliteVdbeAddOp(v, OP_NotExists, base, addr);

  /* If the record number will change, push the record number as it
  ** will be after the update. (The old record number is currently
  ** on top of the stack.)
  */
  if( chngRecno ){



    sqliteExprCode(pParse, pRecnoExpr);
    sqliteVdbeAddOp(v, OP_MustBeInt, 0, 0);

  }

  /* Compute new data for this record.  
  */
  for(i=0; i<pTab->nCol; i++){
    if( i==pTab->iPKey ){
      sqliteVdbeAddOp(v, OP_String, 0, 0);

** 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 1.163 2002/06/29 02:20:09 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

}

/* Opcode: Concat P1 P2 P3
**
** Look at the first P1 elements of the stack.  Append them all 
** together with the lowest element first.  Use P3 as a separator.  
** Put the result on the top of the stack.  The original P1 elements
** are popped from the stack if P2==0 and retained if P2==1.  If
** any element of the stack is NULL, then the result is NULL.
**
** If P3 is NULL, then use no separator.  When P1==1, this routine
** makes a copy of the top stack element into memory obtained
** from sqliteMalloc().
*/
case OP_Concat: {
  char *zNew;

  zSep = pOp->p3;
  if( zSep==0 ) zSep = "";
  nSep = strlen(zSep);
  VERIFY( if( p->tos+1<nField ) goto not_enough_stack; )
  nByte = 1 - nSep;
  for(i=p->tos-nField+1; i<=p->tos; i++){
    if( aStack[i].flags & STK_Null ){
      nByte = -1;
      break;
    }else{
      if( Stringify(p, i) ) goto no_mem;
      nByte += aStack[i].n - 1 + nSep;
    }
  }
  if( nByte<0 ){
    if( pOp->p2==0 ) PopStack(p, nField);
    VERIFY( NeedStack(p, p->tos+1); )
    p->tos++;
    aStack[p->tos].flags = STK_Null;
    zStack[p->tos] = 0;
    break;
  }
  zNew = sqliteMalloc( nByte );
  if( zNew==0 ) goto no_mem;
  j = 0;
  for(i=p->tos-nField+1; i<=p->tos; i++){
    if( (aStack[i].flags & STK_Null)==0 ){
      memcpy(&zNew[j], zStack[i], aStack[i].n-1);

  VERIFY( if( tos<1 ) goto not_enough_stack; )
  if( Stringify(p, tos) || Stringify(p, nos) ) goto no_mem;
  pSorter = sqliteMalloc( sizeof(Sorter) );
  if( pSorter==0 ) goto no_mem;
  pSorter->pNext = p->pSort;
  p->pSort = pSorter;
  assert( aStack[tos].flags & STK_Dyn );

  pSorter->nKey = aStack[tos].n;
  pSorter->zKey = zStack[tos];
  pSorter->nData = aStack[nos].n;
  if( aStack[nos].flags & STK_Dyn ){
    pSorter->pData = zStack[nos];
  }else{
    pSorter->pData = sqliteStrDup(zStack[nos]);
  }
  aStack[tos].flags = 0;
  aStack[nos].flags = 0;
  zStack[tos] = 0;
  zStack[nos] = 0;
  p->tos -= 2;
  break;
}

# 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 expressions.
#
# $Id: expr.test,v 1.25 2002/06/29 02:20:09 drh Exp $

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

# Create a table to work with.
#
execsql {CREATE TABLE test1(i1 int, i2 int, r1 real, r2 real, t1 text, t2 text)}

test_expr expr-3.25 {t1=NULL, t2='hi'} {t1 isnull} 1
test_expr expr-3.25b {t1=NULL, t2='hi'} {t1 is null} 1
test_expr expr-3.26 {t1=NULL, t2='hi'} {t2 isnull} 0
test_expr expr-3.27 {t1=NULL, t2='hi'} {t1 notnull} 0
test_expr expr-3.28 {t1=NULL, t2='hi'} {t2 notnull} 1
test_expr expr-3.28b {t1=NULL, t2='hi'} {t2 is not null} 1
test_expr expr-3.29 {t1='xyz', t2='abc'} {t1||t2} {xyzabc}
test_expr expr-3.30 {t1=NULL, t2='abc'} {t1||t2} {{}}
test_expr expr-3.31 {t1='xyz', t2=NULL} {t1||t2} {{}}
test_expr expr-3.32 {t1='xyz', t2='abc'} {t1||' hi '||t2} {{xyz hi abc}}

test_expr expr-4.1 {t1='abc', t2='Abc'} {t1<t2} 0
test_expr expr-4.2 {t1='abc', t2='Abc'} {t1>t2} 1
test_expr expr-4.3 {t1='abc', t2='Bbc'} {t1<t2} 0
test_expr expr-4.4 {t1='abc', t2='Bbc'} {t1>t2} 1
test_expr expr-4.5 {t1='0', t2='0.0'} {t1==t2} 1

# 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 built-in functions.
#
# $Id: func.test,v 1.13 2002/06/29 02:20:09 drh Exp $

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

# Create a table to work with.
#
do_test func-0.0 {

do_test func-5.4 {
  catchsql {SELECT upper(a,5) FROM t2}
} {1 {wrong number of arguments to function upper()}}
do_test func-5.5 {
  catchsql {SELECT upper(*) FROM t2}
} {1 {wrong number of arguments to function upper()}}

# Test the coalesce() and nullif() functions
#
do_test func-6.1 {
  execsql {SELECT coalesce(a,'xyz') FROM t2}
} {1 xyz 345 xyz 67890}
do_test func-6.2 {
  execsql {SELECT coalesce(upper(a),'nil') FROM t2}
} {1 nil 345 nil 67890}
do_test func-6.3 {
  execsql {SELECT coalesce(nullif(1,1),'nil')}
} {nil}
do_test func-6.4 {
  execsql {SELECT coalesce(nullif(1,2),'nil')}
} {1}
do_test func-6.5 {
  execsql {SELECT coalesce(nullif(1,NULL),'nil')}
} {1}


# Test the last_insert_rowid() function
#
do_test func-7.1 {
  execsql {SELECT last_insert_rowid()}
} [db last_insert_rowid]

# Tests for aggregate functions and how they handle NULLs.
#
do_test func-8.1 {
  execsql {
    SELECT sum(a), count(a), round(avg(a),2), min(a), max(a), count(*) FROM t2;
  }
} {68236 3 22745.33 1 67890 5}
do_test func-8.2 {
  execsql {
    SELECT max('z+'||a||'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP') FROM t2;
  }
} {z+67890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP}
do_test func-8.3 {
  execsql {
    CREATE TEMP TABLE t3 AS SELECT a FROM t2 ORDER BY a DESC;
    SELECT min('z+'||a||'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP') FROM t3;
  }
} {z+1abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP}

# How do you test the random() function in a meaningful, deterministic way?
#
do_test func-9.1 {
  execsql {
    SELECT random() is not null;
  }
} {1}

finish_test

#    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 SELECT statements that are part of
# expressions.
#
# $Id: subselect.test,v 1.6 2002/06/29 02:20:09 drh Exp $

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

# Basic sanity checking.  Try a simple subselect.
#
do_test subselect-1.1 {

# Try something useful.  Delete every entry from t2 where the
# x value is less than half of the maximum.
#
do_test subselect-1.6 {
  execsql {DELETE FROM t2 WHERE x < 0.5*(SELECT max(x) FROM t2)}
  execsql {SELECT x FROM t2 ORDER BY x}
} {2 3 4}

# Make sure sorting works for SELECTs there used as a scalar expression.
#
do_test subselect-2.1 {
  execsql {
    SELECT (SELECT a FROM t1 ORDER BY a), (SELECT a FROM t1 ORDER BY a DESC)
  }
} {1 5}
do_test subselect-2.2 {
  execsql {
    SELECT 1 IN (SELECT a FROM t1 ORDER BY a);
  }
} {1}
do_test subselect-2.3 {
  execsql {
    SELECT 2 IN (SELECT a FROM t1 ORDER BY a DESC);
  }
} {0}

finish_test