xref: /illumos-gate/usr/src/lib/libsqlite/test/subselect.test (revision e3ae4b35c024af1196582063ecee3ab79367227d) 
1#
2# 2001 September 15
3#
4# The author disclaims copyright to this source code.  In place of
5# a legal notice, here is a blessing:
6#
7#    May you do good and not evil.
8#    May you find forgiveness for yourself and forgive others.
9#    May you share freely, never taking more than you give.
10#
11#***********************************************************************
12# This file implements regression tests for SQLite library.  The
13# focus of this file is testing SELECT statements that are part of
14# expressions.
15#
16# $Id: subselect.test,v 1.7 2002/07/15 18:55:26 drh Exp $
17
18set testdir [file dirname $argv0]
19source $testdir/tester.tcl
20
21# Basic sanity checking.  Try a simple subselect.
22#
23do_test subselect-1.1 {
24  execsql {
25    CREATE TABLE t1(a int, b int);
26    INSERT INTO t1 VALUES(1,2);
27    INSERT INTO t1 VALUES(3,4);
28    INSERT INTO t1 VALUES(5,6);
29  }
30  execsql {SELECT * FROM t1 WHERE a = (SELECT count(*) FROM t1)}
31} {3 4}
32
33# Try a select with more than one result column.
34#
35do_test subselect-1.2 {
36  set v [catch {execsql {SELECT * FROM t1 WHERE a = (SELECT * FROM t1)}} msg]
37  lappend v $msg
38} {1 {only a single result allowed for a SELECT that is part of an expression}}
39
40# A subselect without an aggregate.
41#
42do_test subselect-1.3a {
43  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=2)}
44} {2}
45do_test subselect-1.3b {
46  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=4)}
47} {4}
48do_test subselect-1.3c {
49  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=6)}
50} {6}
51do_test subselect-1.3c {
52  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=8)}
53} {}
54
55# What if the subselect doesn't return any value.  We should get
56# NULL as the result.  Check it out.
57#
58do_test subselect-1.4 {
59  execsql {SELECT b from t1 where a = coalesce((SELECT a FROM t1 WHERE b=5),1)}
60} {2}
61
62# Try multiple subselects within a single expression.
63#
64do_test subselect-1.5 {
65  execsql {
66    CREATE TABLE t2(x int, y int);
67    INSERT INTO t2 VALUES(1,2);
68    INSERT INTO t2 VALUES(2,4);
69    INSERT INTO t2 VALUES(3,8);
70    INSERT INTO t2 VALUES(4,16);
71  }
72  execsql {
73    SELECT y from t2
74    WHERE x = (SELECT sum(b) FROM t1 where a notnull) - (SELECT sum(a) FROM t1)
75  }
76} {8}
77
78# Try something useful.  Delete every entry from t2 where the
79# x value is less than half of the maximum.
80#
81do_test subselect-1.6 {
82  execsql {DELETE FROM t2 WHERE x < 0.5*(SELECT max(x) FROM t2)}
83  execsql {SELECT x FROM t2 ORDER BY x}
84} {2 3 4}
85
86# Make sure sorting works for SELECTs there used as a scalar expression.
87#
88do_test subselect-2.1 {
89  execsql {
90    SELECT (SELECT a FROM t1 ORDER BY a), (SELECT a FROM t1 ORDER BY a DESC)
91  }
92} {1 5}
93do_test subselect-2.2 {
94  execsql {
95    SELECT 1 IN (SELECT a FROM t1 ORDER BY a);
96  }
97} {1}
98do_test subselect-2.3 {
99  execsql {
100    SELECT 2 IN (SELECT a FROM t1 ORDER BY a DESC);
101  }
102} {0}
103
104# Verify that the ORDER BY clause is honored in a subquery.
105#
106do_test subselect-3.1 {
107  execsql {
108    CREATE TABLE t3(x int);
109    INSERT INTO t3 SELECT a FROM t1 UNION ALL SELECT b FROM t1;
110    SELECT * FROM t3 ORDER BY x;
111  }
112} {1 2 3 4 5 6}
113do_test subselect-3.2 {
114  execsql {
115    SELECT sum(x) FROM (SELECT x FROM t3 ORDER BY x LIMIT 2);
116  }
117} {3}
118do_test subselect-3.3 {
119  execsql {
120    SELECT sum(x) FROM (SELECT x FROM t3 ORDER BY x DESC LIMIT 2);
121  }
122} {11}
123do_test subselect-3.4 {
124  execsql {
125    SELECT (SELECT x FROM t3 ORDER BY x);
126  }
127} {1}
128do_test subselect-3.5 {
129  execsql {
130    SELECT (SELECT x FROM t3 ORDER BY x DESC);
131  }
132} {6}
133do_test subselect-3.6 {
134  execsql {
135    SELECT (SELECT x FROM t3 ORDER BY x LIMIT 1);
136  }
137} {1}
138do_test subselect-3.7 {
139  execsql {
140    SELECT (SELECT x FROM t3 ORDER BY x DESC LIMIT 1);
141  }
142} {6}
143do_test subselect-3.8 {
144  execsql {
145    SELECT (SELECT x FROM t3 ORDER BY x LIMIT 1 OFFSET 2);
146  }
147} {3}
148do_test subselect-3.9 {
149  execsql {
150    SELECT (SELECT x FROM t3 ORDER BY x DESC LIMIT 1 OFFSET 2);
151  }
152} {4}
153
154
155
156finish_test
157