/ Artifact Content
Login

Artifact bf8b251a92fb091973c1c469ce499dc9648a41d5:


# Copyright (c) 1999, 2000 D. Richard Hipp
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA  02111-1307, USA.
#
# Author contact information:
#   drh@hwaci.com
#   http://www.hwaci.com/drh/
#
#***********************************************************************
# 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 1.3 2000/06/05 21:39:49 drh Exp $

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

# Basic sanity checking.  Try a simple subselect.
#
do_test subselect-1.1 {
  execsql {
    CREATE TABLE t1(a int, b int);
    INSERT INTO t1 VALUES(1,2);
    INSERT INTO t1 VALUES(3,4);
    INSERT INTO t1 VALUES(5,6);
  }
  execsql {SELECT * FROM t1 WHERE a = (SELECT count(*) FROM t1)}
} {3 4}

# Try a select with more than one result column.
#
do_test subselect-1.2 {
  set v [catch {execsql {SELECT * FROM t1 WHERE a = (SELECT * FROM t1)}} msg]
  lappend v $msg
} {1 {only a single result allowed for a SELECT that is part of an expression}}

# A subselect without an aggregate.
#
do_test subselect-1.3a {
  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=2)}
} {2}
do_test subselect-1.3b {
  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=4)}
} {4}
do_test subselect-1.3c {
  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=6)}
} {6}
do_test subselect-1.3c {
  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=8)}
} {}

# What if the subselect doesn't return any value.  We should get
# NULL as the result.  Check it out.
#
do_test subselect-1.4 {
  execsql {INSERT INTO t1 VALUES(NULL,8)}
  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=5)}
} {8}

# Try multiple subselects within a single expression.
#
do_test subselect-1.5 {
  execsql {
    CREATE TABLE t2(x int, y int);
    INSERT INTO t2 VALUES(1,2);
    INSERT INTO t2 VALUES(2,4);
    INSERT INTO t2 VALUES(3,8);
    INSERT INTO t2 VALUES(4,16);
  }
  execsql {
    SELECT y from t2 
    WHERE x = (SELECT sum(b) FROM t1 where a notnull) - (SELECT sum(a) FROM t1)
  }
} {8}

# 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}

finish_test