# 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 SELECT statements that are part of

# expressions.

#

# $Id: subselect.test,v 1.16 2008/08/04 03:51:24 danielk1977 Exp $

set testdir [file dirname $argv0]

source $testdir/tester.tcl

# Omit this whole file if the library is build without subquery support.

ifcapable !subquery {

  finish_test

  return

}

# 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-1.3d {

  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=8)}

} {}

ifcapable compound {

  do_test subselect-1.3e {

    execsql {

      SELECT b FROM t1

       WHERE a = (SELECT a FROM t1 UNION SELECT b FROM t1 ORDER BY 1);

    }

  } {2}

}

# 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 {SELECT b from t1 where a = coalesce((SELECT a FROM t1 WHERE b=5),1)}

} {2}

# 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}

# 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}

# Verify that the ORDER BY clause is honored in a subquery.

#

ifcapable compound {

do_test subselect-3.1 {

  execsql {

    CREATE TABLE t3(x int);

    INSERT INTO t3 SELECT a FROM t1 UNION ALL SELECT b FROM t1;

    SELECT * FROM t3 ORDER BY x;

  }

} {1 2 3 4 5 6}

} ;# ifcapable compound

ifcapable !compound {

do_test subselect-3.1 {

  execsql {

    CREATE TABLE t3(x int);

    INSERT INTO t3 SELECT a FROM t1; 

    INSERT INTO t3 SELECT b FROM t1;

    SELECT * FROM t3 ORDER BY x;

  }

} {1 2 3 4 5 6}

} ;# ifcapable !compound

do_test subselect-3.2 {

  execsql {

    SELECT sum(x) FROM (SELECT x FROM t3 ORDER BY x LIMIT 2);

  }

} {3}

do_test subselect-3.3 {

  execsql {

    SELECT sum(x) FROM (SELECT x FROM t3 ORDER BY x DESC LIMIT 2);

  }

} {11}

do_test subselect-3.4 {

  execsql {

    SELECT (SELECT x FROM t3 ORDER BY x);

  }

} {1}

do_test subselect-3.5 {

  execsql {

    SELECT (SELECT x FROM t3 ORDER BY x DESC);

  }

} {6}

do_test subselect-3.6 {

  execsql {

    SELECT (SELECT x FROM t3 ORDER BY x LIMIT 1);

  }

} {1}

do_test subselect-3.7 {

  execsql {

    SELECT (SELECT x FROM t3 ORDER BY x DESC LIMIT 1);

  }

} {6}

do_test subselect-3.8 {

  execsql {

    SELECT (SELECT x FROM t3 ORDER BY x LIMIT 1 OFFSET 2);

  }

} {3}

do_test subselect-3.9 {

  execsql {

    SELECT (SELECT x FROM t3 ORDER BY x DESC LIMIT 1 OFFSET 2);

  }

} {4}

do_test subselect-3.10 {

  execsql {

    SELECT x FROM t3 WHERE x IN

       (SELECT x FROM t3 ORDER BY x DESC LIMIT 1 OFFSET 2);

  }

} {4}

# Ticket #2295.

# Make sure type affinities work correctly on subqueries with

# an ORDER BY clause.

#

do_test subselect-4.1 {

  execsql {

    CREATE TABLE t4(a TEXT, b TEXT);

    INSERT INTO t4 VALUES('a','1');

    INSERT INTO t4 VALUES('b','2');

    INSERT INTO t4 VALUES('c','3');

    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b);

  }

} {a b c}

do_test subselect-4.2 {

  execsql {

    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b LIMIT 1);

  }

} {a}

do_test subselect-4.3 {

  execsql {

    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b DESC LIMIT 1);

  }

} {c}

finish_test