xref: /sqlite-3.40.0/test/subselect.test (revision 85e9e22b) 
1# 2001 September 15
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# This file implements regression tests for SQLite library.  The
12# focus of this file is testing SELECT statements that are part of
13# expressions.
14#
15# $Id: subselect.test,v 1.15 2008/07/15 00:27:35 drh Exp $
16
17set testdir [file dirname $argv0]
18source $testdir/tester.tcl
19
20# Omit this whole file if the library is build without subquery support.
21ifcapable !subquery {
22  finish_test
23  return
24}
25
26# Basic sanity checking.  Try a simple subselect.
27#
28do_test subselect-1.1 {
29  execsql {
30    CREATE TABLE t1(a int, b int);
31    INSERT INTO t1 VALUES(1,2);
32    INSERT INTO t1 VALUES(3,4);
33    INSERT INTO t1 VALUES(5,6);
34  }
35  execsql {SELECT * FROM t1 WHERE a = (SELECT count(*) FROM t1)}
36} {3 4}
37
38# Try a select with more than one result column.
39#
40do_test subselect-1.2 {
41  set v [catch {execsql {SELECT * FROM t1 WHERE a = (SELECT * FROM t1)}} msg]
42  lappend v $msg
43} {1 {only a single result allowed for a SELECT that is part of an expression}}
44
45# A subselect without an aggregate.
46#
47do_test subselect-1.3a {
48  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=2)}
49} {2}
50do_test subselect-1.3b {
51  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=4)}
52} {4}
53do_test subselect-1.3c {
54  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=6)}
55} {6}
56do_test subselect-1.3d {
57  execsql {SELECT b from t1 where a = (SELECT a FROM t1 WHERE b=8)}
58} {}
59do_test subselect-1.3e {
60  execsql {
61    SELECT b FROM t1
62     WHERE a = (SELECT a FROM t1 UNION SELECT b FROM t1 ORDER BY 1);
63  }
64} {2}
65
66# What if the subselect doesn't return any value.  We should get
67# NULL as the result.  Check it out.
68#
69do_test subselect-1.4 {
70  execsql {SELECT b from t1 where a = coalesce((SELECT a FROM t1 WHERE b=5),1)}
71} {2}
72
73# Try multiple subselects within a single expression.
74#
75do_test subselect-1.5 {
76  execsql {
77    CREATE TABLE t2(x int, y int);
78    INSERT INTO t2 VALUES(1,2);
79    INSERT INTO t2 VALUES(2,4);
80    INSERT INTO t2 VALUES(3,8);
81    INSERT INTO t2 VALUES(4,16);
82  }
83  execsql {
84    SELECT y from t2
85    WHERE x = (SELECT sum(b) FROM t1 where a notnull) - (SELECT sum(a) FROM t1)
86  }
87} {8}
88
89# Try something useful.  Delete every entry from t2 where the
90# x value is less than half of the maximum.
91#
92do_test subselect-1.6 {
93  execsql {DELETE FROM t2 WHERE x < 0.5*(SELECT max(x) FROM t2)}
94  execsql {SELECT x FROM t2 ORDER BY x}
95} {2 3 4}
96
97# Make sure sorting works for SELECTs there used as a scalar expression.
98#
99do_test subselect-2.1 {
100  execsql {
101    SELECT (SELECT a FROM t1 ORDER BY a), (SELECT a FROM t1 ORDER BY a DESC)
102  }
103} {1 5}
104do_test subselect-2.2 {
105  execsql {
106    SELECT 1 IN (SELECT a FROM t1 ORDER BY a);
107  }
108} {1}
109do_test subselect-2.3 {
110  execsql {
111    SELECT 2 IN (SELECT a FROM t1 ORDER BY a DESC);
112  }
113} {0}
114
115# Verify that the ORDER BY clause is honored in a subquery.
116#
117ifcapable compound {
118do_test subselect-3.1 {
119  execsql {
120    CREATE TABLE t3(x int);
121    INSERT INTO t3 SELECT a FROM t1 UNION ALL SELECT b FROM t1;
122    SELECT * FROM t3 ORDER BY x;
123  }
124} {1 2 3 4 5 6}
125} ;# ifcapable compound
126ifcapable !compound {
127do_test subselect-3.1 {
128  execsql {
129    CREATE TABLE t3(x int);
130    INSERT INTO t3 SELECT a FROM t1;
131    INSERT INTO t3 SELECT b FROM t1;
132    SELECT * FROM t3 ORDER BY x;
133  }
134} {1 2 3 4 5 6}
135} ;# ifcapable !compound
136
137do_test subselect-3.2 {
138  execsql {
139    SELECT sum(x) FROM (SELECT x FROM t3 ORDER BY x LIMIT 2);
140  }
141} {3}
142do_test subselect-3.3 {
143  execsql {
144    SELECT sum(x) FROM (SELECT x FROM t3 ORDER BY x DESC LIMIT 2);
145  }
146} {11}
147do_test subselect-3.4 {
148  execsql {
149    SELECT (SELECT x FROM t3 ORDER BY x);
150  }
151} {1}
152do_test subselect-3.5 {
153  execsql {
154    SELECT (SELECT x FROM t3 ORDER BY x DESC);
155  }
156} {6}
157do_test subselect-3.6 {
158  execsql {
159    SELECT (SELECT x FROM t3 ORDER BY x LIMIT 1);
160  }
161} {1}
162do_test subselect-3.7 {
163  execsql {
164    SELECT (SELECT x FROM t3 ORDER BY x DESC LIMIT 1);
165  }
166} {6}
167do_test subselect-3.8 {
168  execsql {
169    SELECT (SELECT x FROM t3 ORDER BY x LIMIT 1 OFFSET 2);
170  }
171} {3}
172do_test subselect-3.9 {
173  execsql {
174    SELECT (SELECT x FROM t3 ORDER BY x DESC LIMIT 1 OFFSET 2);
175  }
176} {4}
177do_test subselect-3.10 {
178  execsql {
179    SELECT x FROM t3 WHERE x IN
180       (SELECT x FROM t3 ORDER BY x DESC LIMIT 1 OFFSET 2);
181  }
182} {4}
183
184# Ticket #2295.
185# Make sure type affinities work correctly on subqueries with
186# an ORDER BY clause.
187#
188do_test subselect-4.1 {
189  execsql {
190    CREATE TABLE t4(a TEXT, b TEXT);
191    INSERT INTO t4 VALUES('a','1');
192    INSERT INTO t4 VALUES('b','2');
193    INSERT INTO t4 VALUES('c','3');
194    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b);
195  }
196} {a b c}
197do_test subselect-4.2 {
198  execsql {
199    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b LIMIT 1);
200  }
201} {a}
202do_test subselect-4.3 {
203  execsql {
204    SELECT a FROM t4 WHERE b IN (SELECT b FROM t4 ORDER BY b DESC LIMIT 1);
205  }
206} {c}
207
208finish_test
209