# Initialise --disable_warnings drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12; --enable_warnings select (select 2); explain select (select 2); SELECT (SELECT 1) UNION SELECT (SELECT 2); explain SELECT (SELECT 1) UNION SELECT (SELECT 2); SELECT (SELECT (SELECT 0 UNION SELECT 0)); explain SELECT (SELECT (SELECT 0 UNION SELECT 0)); -- error 1245 SELECT (SELECT 1 FROM (SELECT 1) as b HAVING a=1) as a; -- error 1245 SELECT (SELECT 1 FROM (SELECT 1) as b HAVING b=1) as a,(SELECT 1 FROM (SELECT 1) as c HAVING a=1) as b; SELECT (SELECT 1),MAX(1) FROM (SELECT 1) as a; -- error 1245 SELECT (SELECT a) as a; EXPLAIN SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1; SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1; -- error 1054 SELECT (SELECT 1), a; SELECT 1 as a FROM (SELECT 1) as b HAVING (SELECT a)=1; -- error 1054 SELECT 1 FROM (SELECT (SELECT a) b) c; SELECT * FROM (SELECT 1 as id) b WHERE id IN (SELECT * FROM (SELECT 1 as id) c ORDER BY id); -- error 1239 SELECT * FROM (SELECT 1) a WHERE 1 IN (SELECT 1,1); SELECT 1 IN (SELECT 1); SELECT 1 FROM (SELECT 1 as a) b WHERE 1 IN (SELECT (SELECT a)); -- error 1221 select (SELECT 1 FROM (SELECT 1) a PROCEDURE ANALYSE(1)); -- error 1108 SELECT 1 FROM (SELECT 1) a PROCEDURE ANALYSE((SELECT 1)); SELECT (SELECT 1) as a FROM (SELECT 1) b WHERE (SELECT a) IS NULL; SELECT (SELECT 1) as a FROM (SELECT 1) b WHERE (SELECT a) IS NOT NULL; SELECT (SELECT 1,2,3) = ROW(1,2,3); SELECT (SELECT 1,2,3) = ROW(1,2,1); SELECT (SELECT 1,2,3) < ROW(1,2,1); SELECT (SELECT 1,2,3) > ROW(1,2,1); SELECT (SELECT 1,2,3) = ROW(1,2,NULL); SELECT ROW(1,2,3) = (SELECT 1,2,3); SELECT ROW(1,2,3) = (SELECT 1,2,1); SELECT ROW(1,2,3) < (SELECT 1,2,1); SELECT ROW(1,2,3) > (SELECT 1,2,1); SELECT ROW(1,2,3) = (SELECT 1,2,NULL); SELECT (SELECT 1.5,2,'a') = ROW(1.5,2,'a'); SELECT (SELECT 1.5,2,'a') = ROW(1.5,2,'b'); SELECT (SELECT 1.5,2,'a') = ROW('b',2,'b'); SELECT (SELECT 'b',2,'a') = ROW(1.5,2,'a'); SELECT (SELECT 1.5,2,'a') = ROW(1.5,'c','a'); SELECT (SELECT 1.5,'c','a') = ROW(1.5,2,'a'); -- error 1239 SELECT (SELECT * FROM (SELECT 'test' a,'test' b) a); SELECT 1 as a,(SELECT a+a) b,(SELECT b); create table t1 (a int); create table t2 (a int, b int); create table t3 (a int); create table t4 (a int, b int); insert into t1 values (2); insert into t2 values (1,7),(2,7); insert into t4 values (4,8),(3,8),(5,9); -- error 1245 select (select a from t1 where t1.a = a1) as a2, (select b from t2 where t2.b=a2) as a1; select (select a from t1 where t1.a=t2.a), a from t2; select (select a from t1 where t1.a=t2.b), a from t2; select (select a from t1), a from t2; select (select a from t3), a from t2; select * from t2 where t2.a=(select a from t1); insert into t3 values (6),(7),(3); select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1); (select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)) union (select * from t4 order by a limit 2) limit 3; (select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)) union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a); explain (select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)) union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a); select (select a from t3 where a1) as tt; explain select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from (select * from t2 where a>1) as tt; select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1); select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a > t1.a) order by 1 desc limit 1); select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3 where t3.a < t1.a) order by 1 desc limit 1); select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4; explain select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4; select * from t3 where exists (select * from t2 where t2.b=t3.a); select * from t3 where not exists (select * from t2 where t2.b=t3.a); select * from t3 where a in (select b from t2); select * from t3 where a not in (select b from t2); select * from t3 where a = some (select b from t2); select * from t3 where a <> any (select b from t2); # Rewrite: select * from t3 where not exists (select b from t2 where a <> b); select * from t3 where a = all (select b from t2); select * from t3 where a <> all (select b from t2); insert into t2 values (100, 5); select * from t3 where a < any (select b from t2); select * from t3 where a < all (select b from t2); select * from t3 where a >= any (select b from t2); select * from t3 where a >= all (select b from t2); delete from t2 where a=100; -- error 1239 select * from t3 where a in (select a,b from t2); -- error 1239 select * from t3 where a in (select * from t2); insert into t4 values (12,7),(1,7),(10,9),(9,6),(7,6),(3,9); select b,max(a) as ma from t4 group by b having b < (select max(t2.a) from t2 where t2.b=t4.b); select b,max(a) as ma from t4 group by b having b >= (select max(t2.a) from t2 where t2.b=t4.b); create table t5 (a int); select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2; insert into t5 values (5); select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2; insert into t5 values (2); select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2; explain select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2; -- error 1240 select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2; create table t6 (patient_uq int, clinic_uq int, index i1 (clinic_uq)); create table t7( uq int primary key, name char(25)); insert into t7 values(1,"Oblastnaia bolnitsa"),(2,"Bolnitsa Krasnogo Kresta"); insert into t6 values (1,1),(1,2),(2,2),(1,3); select * from t6 where exists (select * from t7 where uq = clinic_uq); # not unique fields -- error 1052 select * from t1 where a= (select a from t2,t4 where t2.b=t4.b); # different tipes & group functions drop table if exists t1,t2,t3; CREATE TABLE t3 (a varchar(20),b char(1) NOT NULL default '0'); INSERT INTO t3 VALUES ('W','a'),('A','c'),('J','b'); CREATE TABLE t2 (a varchar(20),b int NOT NULL default '0'); INSERT INTO t2 VALUES ('W','1'),('A','3'),('J','2'); CREATE TABLE t1 (a varchar(20),b date NOT NULL default '0000-00-00'); INSERT INTO t1 VALUES ('W','1732-02-22'),('A','1735-10-30'),('J','1743-04-13'); SELECT * FROM t1 WHERE b = (SELECT MIN(b) FROM t1); SELECT * FROM t2 WHERE b = (SELECT MIN(b) FROM t2); SELECT * FROM t3 WHERE b = (SELECT MIN(b) FROM t3); CREATE TABLE `t8` ( `pseudo` varchar(35) character set latin1 NOT NULL default '', `email` varchar(60) character set latin1 NOT NULL default '', PRIMARY KEY (`pseudo`), UNIQUE KEY `email` (`email`) ) TYPE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC; INSERT INTO t8 (pseudo,email) VALUES ('joce','test'); INSERT INTO t8 (pseudo,email) VALUES ('joce1','test1'); INSERT INTO t8 (pseudo,email) VALUES ('2joce1','2test1'); EXPLAIN SELECT pseudo,(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce')) FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'); -- error 1239 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM t8 WHERE pseudo='joce'); -- error 1239 SELECT pseudo FROM t8 WHERE pseudo=(SELECT * FROM t8 WHERE pseudo='joce'); SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'); -- error 1240 SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo LIKE '%joce%'); drop table if exists t1,t2,t3,t4,t5,t6,t7,t8; #searchconthardwarefr3 forumconthardwarefr7 CREATE TABLE `t1` ( `topic` mediumint(8) unsigned NOT NULL default '0', `date` date NOT NULL default '0000-00-00', `pseudo` varchar(35) character set latin1 NOT NULL default '', PRIMARY KEY (`pseudo`,`date`,`topic`), KEY `topic` (`topic`) ) TYPE=MyISAM ROW_FORMAT=DYNAMIC; INSERT INTO t1 (topic,date,pseudo) VALUES ('43506','2002-10-02','joce'),('40143','2002-08-03','joce'); EXPLAIN SELECT DISTINCT date FROM t1 WHERE date='2002-08-03'; EXPLAIN SELECT (SELECT DISTINCT date FROM t1 WHERE date='2002-08-03'); SELECT DISTINCT date FROM t1 WHERE date='2002-08-03'; SELECT (SELECT DISTINCT date FROM t1 WHERE date='2002-08-03'); SELECT 1 FROM t1 WHERE 1=(SELECT 1 UNION SELECT 1) UNION ALL SELECT 1; -- error 1240 SELECT 1 FROM t1 WHERE 1=(SELECT 1 UNION ALL SELECT 1) UNION SELECT 1; EXPLAIN SELECT 1 FROM t1 WHERE 1=(SELECT 1 UNION SELECT 1); drop table t1; #forumconthardwarefr7 searchconthardwarefr7 CREATE TABLE `t1` ( `numeropost` mediumint(8) unsigned NOT NULL auto_increment, `maxnumrep` int(10) unsigned NOT NULL default '0', PRIMARY KEY (`numeropost`), UNIQUE KEY `maxnumrep` (`maxnumrep`) ) TYPE=MyISAM ROW_FORMAT=FIXED; INSERT INTO t1 (numeropost,maxnumrep) VALUES (40143,1),(43506,2); CREATE TABLE `t2` ( `mot` varchar(30) NOT NULL default '', `topic` mediumint(8) unsigned NOT NULL default '0', `date` date NOT NULL default '0000-00-00', `pseudo` varchar(35) NOT NULL default '', PRIMARY KEY (`mot`,`pseudo`,`date`,`topic`) ) TYPE=MyISAM ROW_FORMAT=DYNAMIC; INSERT INTO t2 (mot,topic,date,pseudo) VALUES ('joce','40143','2002-10-22','joce'), ('joce','43506','2002-10-22','joce'); select numeropost as a FROM t1 GROUP BY (SELECT 1 FROM t1 HAVING a=1); SELECT numeropost,maxnumrep FROM t1 WHERE exists (SELECT 1 FROM t2 WHERE (mot='joce') AND date >= '2002-10-21' AND t1.numeropost = t2.topic) ORDER BY maxnumrep DESC LIMIT 0, 20; -- error 1054 SELECT (SELECT 1) as a FROM (SELECT 1 FROM t1 HAVING a=1) b; -- error 1054 SELECT 1 IN (SELECT 1 FROM t2 HAVING a); SELECT * from t2 where topic IN (SELECT topic FROM t2 GROUP BY topic); SELECT * from t2 where topic IN (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100); SELECT * from t2 where topic IN (SELECT SUM(topic) FROM t1); SELECT * from t2 where topic = any (SELECT topic FROM t2 GROUP BY topic); SELECT * from t2 where topic = any (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100); SELECT * from t2 where topic = any (SELECT SUM(topic) FROM t1); SELECT * from t2 where topic = all (SELECT topic FROM t2 GROUP BY topic); SELECT * from t2 where topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100); SELECT *, topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100) from t2; SELECT * from t2 where topic = all (SELECT SUM(topic) FROM t2); SELECT * from t2 where topic <> any (SELECT SUM(topic) FROM t2); SELECT * from t2 where topic IN (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000); SELECT * from t2 where topic = any (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000); SELECT * from t2 where topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000); SELECT *, topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000) from t2; drop table t1,t2; #forumconthardwarefr7 CREATE TABLE `t1` ( `numeropost` mediumint(8) unsigned NOT NULL auto_increment, `maxnumrep` int(10) unsigned NOT NULL default '0', PRIMARY KEY (`numeropost`), UNIQUE KEY `maxnumrep` (`maxnumrep`) ) TYPE=MyISAM ROW_FORMAT=FIXED; INSERT INTO t1 (numeropost,maxnumrep) VALUES (1,0),(2,1); -- error 1240 select numeropost as a FROM t1 GROUP BY (SELECT 1 FROM t1 HAVING a=1); -- error 1240 select numeropost as a FROM t1 ORDER BY (SELECT 1 FROM t1 HAVING a=1); drop table t1; #iftest CREATE TABLE t1 (field char(1) NOT NULL DEFAULT 'b'); INSERT INTO t1 VALUES (); -- error 1240 SELECT field FROM t1 WHERE 1=(SELECT 1 UNION ALL SELECT 1 FROM (SELECT 1) a HAVING field='b'); drop table t1; # threadhardwarefr7 CREATE TABLE `t1` ( `numeropost` mediumint(8) unsigned NOT NULL default '0', `numreponse` int(10) unsigned NOT NULL auto_increment, `pseudo` varchar(35) NOT NULL default '', PRIMARY KEY (`numeropost`,`numreponse`), UNIQUE KEY `numreponse` (`numreponse`), KEY `pseudo` (`pseudo`,`numeropost`) ) TYPE=MyISAM; -- error 1245 SELECT (SELECT numeropost FROM t1 HAVING numreponse=a),numreponse FROM (SELECT * FROM t1) as a; -- error 1054 SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=a) FROM (SELECT * FROM t1) as a; SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT * FROM t1) as a; INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test'); -- error 1240 EXPLAIN SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1'); EXPLAIN SELECT MAX(numreponse) FROM t1 WHERE numeropost='1'; EXPLAIN SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT MAX(numreponse) FROM t1 WHERE numeropost='1'); drop table t1; CREATE TABLE t1 (a int(1)); INSERT INTO t1 VALUES (1); SELECT 1 FROM (SELECT a FROM t1) b HAVING (SELECT b.a)=1; drop table t1; #update with subselects create table t1 (a int NOT NULL, b int, primary key (a)); create table t2 (a int NOT NULL, b int, primary key (a)); insert into t1 values (0, 10),(1, 11),(2, 12); insert into t2 values (1, 21),(2, 22),(3, 23); select * from t1; -- error 1093 update t1 set b= (select b from t1); -- error 1240 update t1 set b= (select b from t2); update t1 set b= (select b from t2 where t1.a = t2.a); select * from t1; drop table t1, t2; #delete with subselects create table t1 (a int NOT NULL, b int, primary key (a)); create table t2 (a int NOT NULL, b int, primary key (a)); insert into t1 values (0, 10),(1, 11),(2, 12); insert into t2 values (1, 21),(2, 12),(3, 23); select * from t1; select * from t1 where b = (select b from t2 where t1.a = t2.a); -- error 1093 delete from t1 where b = (select b from t1); -- error 1240 delete from t1 where b = (select b from t2); delete from t1 where b = (select b from t2 where t1.a = t2.a); select * from t1; drop table t1, t2; #multi-delete with subselects create table t11 (a int NOT NULL, b int, primary key (a)); create table t12 (a int NOT NULL, b int, primary key (a)); create table t2 (a int NOT NULL, b int, primary key (a)); insert into t11 values (0, 10),(1, 11),(2, 12); insert into t12 values (33, 10),(22, 11),(2, 12); insert into t2 values (1, 21),(2, 12),(3, 23); select * from t11; select * from t12; -- error 1093 delete t11.*, t12.* from t11,t12 where t11.a = t12.a and t11.b = (select b from t12 where t11.a = t12.a); -- error 1240 delete t11.*, t12.* from t11,t12 where t11.a = t12.a and t11.b = (select b from t2); delete t11.*, t12.* from t11,t12 where t11.a = t12.a and t11.b = (select b from t2 where t11.a = t2.a); select * from t11; select * from t12; drop table t11, t12, t2; #insert with subselects CREATE TABLE t1 (x int); create table t2 (a int); create table t3 (a int); insert into t2 values (1); insert into t3 values (1),(2); -- error 1093 INSERT INTO t1 (x) VALUES ((SELECT x FROM t1)); -- error 1240 INSERT INTO t1 (x) VALUES ((SELECT a FROM t3)); INSERT INTO t1 (x) VALUES ((SELECT a FROM t2)); select * from t1; insert into t2 values (1); INSERT DELAYED INTO t1 (x) VALUES ((SELECT SUM(a) FROM t2)); -- sleep 1 select * from t1; INSERT INTO t1 (x) select (SELECT SUM(a)+1 FROM t2) FROM t2; select * from t1; -- error 1093 INSERT INTO t1 (x) select (SELECT SUM(x)+2 FROM t1) FROM t2; INSERT DELAYED INTO t1 (x) VALUES ((SELECT SUM(x) FROM t2)); -- sleep 1 select * from t1; drop table t1, t2, t3; #replace with subselects CREATE TABLE t1 (x int not null, y int, primary key (x)); create table t2 (a int); create table t3 (a int); insert into t2 values (1); insert into t3 values (1),(2); select * from t1; -- error 1093 replace into t1 (x, y) VALUES ((SELECT x FROM t1), (SELECT a+1 FROM t2)); -- error 1240 replace into t1 (x, y) VALUES ((SELECT a FROM t3), (SELECT a+1 FROM t2)); replace into t1 (x, y) VALUES ((SELECT a FROM t2), (SELECT a+1 FROM t2)); select * from t1; replace into t1 (x, y) VALUES ((SELECT a FROM t2), (SELECT a+2 FROM t2)); select * from t1; replace DELAYED into t1 (x, y) VALUES ((SELECT a+3 FROM t2), (SELECT a FROM t2)); -- sleep 1 select * from t1; replace DELAYED into t1 (x, y) VALUES ((SELECT a+3 FROM t2), (SELECT a+1 FROM t2)); -- sleep 1 select * from t1; replace LOW_PRIORITY into t1 (x, y) VALUES ((SELECT a+1 FROM t2), (SELECT a FROM t2)); select * from t1; drop table t1, t2, t3; -- error 1096 SELECT * FROM (SELECT 1) b WHERE 1 IN (SELECT *); CREATE TABLE t2 (id int(11) default NULL, KEY id (id)) TYPE=MyISAM CHARSET=latin1; INSERT INTO t2 VALUES (1),(2); SELECT * FROM t2 WHERE id IN (SELECT 1); EXPLAIN SELECT * FROM t2 WHERE id IN (SELECT 1); SELECT * FROM t2 WHERE id IN (SELECT 1 UNION SELECT 3); SELECT * FROM t2 WHERE id IN (SELECT 1+(select 1)); EXPLAIN SELECT * FROM t2 WHERE id IN (SELECT 1+(select 1)); EXPLAIN SELECT * FROM t2 WHERE id IN (SELECT 1 UNION SELECT 3); SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 3); SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 2); -- error 1093 INSERT INTO t2 VALUES ((SELECT * FROM t2)); SELECT * FROM t2; CREATE TABLE t1 (id int(11) default NULL, KEY id (id)) TYPE=MyISAM CHARSET=latin1; INSERT INTO t1 values (1),(1); -- error 1240 UPDATE t2 SET id=(SELECT * FROM t1); drop table t2, t1; #NULL test create table t1 (a int); insert into t1 values (1),(2),(3); select 1 IN (SELECT * from t1); select 10 IN (SELECT * from t1); select NULL IN (SELECT * from t1); update t1 set a=NULL where a=2; select 1 IN (SELECT * from t1); select 3 IN (SELECT * from t1); select 10 IN (SELECT * from t1); select 1 > ALL (SELECT * from t1); select 10 > ALL (SELECT * from t1); select 1 > ANY (SELECT * from t1); select 10 > ANY (SELECT * from t1); drop table t1; create table t1 (a varchar(20)); insert into t1 values ('A'),('BC'),('DEF'); select 'A' IN (SELECT * from t1); select 'XYZS' IN (SELECT * from t1); select NULL IN (SELECT * from t1); update t1 set a=NULL where a='BC'; select 'A' IN (SELECT * from t1); select 'DEF' IN (SELECT * from t1); select 'XYZS' IN (SELECT * from t1); select 'A' > ALL (SELECT * from t1); select 'XYZS' > ALL (SELECT * from t1); select 'A' > ANY (SELECT * from t1); select 'XYZS' > ANY (SELECT * from t1); drop table t1; create table t1 (a float); insert into t1 values (1.5),(2.5),(3.5); select 1.5 IN (SELECT * from t1); select 10.5 IN (SELECT * from t1); select NULL IN (SELECT * from t1); update t1 set a=NULL where a=2.5; select 1.5 IN (SELECT * from t1); select 3.5 IN (SELECT * from t1); select 10.5 IN (SELECT * from t1); select 1.5 > ALL (SELECT * from t1); select 10.5 > ALL (SELECT * from t1); select 1.5 > ANY (SELECT * from t1); select 10.5 > ANY (SELECT * from t1); explain select (select a+1) from t1; select (select a+1) from t1; drop table t1; # # Null with keys # CREATE TABLE t1 (a int(11) NOT NULL default '0', PRIMARY KEY (a)); CREATE TABLE t2 (a int(11) default '0', INDEX (a)); INSERT INTO t1 VALUES (1),(2),(3),(4); INSERT INTO t2 VALUES (1),(2),(3); SELECT t1.a, t1.a in (select t2.a from t2) FROM t1; explain SELECT t1.a, t1.a in (select t2.a from t2) FROM t1; drop table t1,t2; #LIMIT is not supported now create table t1 (a float); -- error 1235 select 10.5 IN (SELECT * from t1 LIMIT 1); -- error 1235 select 10.5 IN (SELECT * from t1 LIMIT 1 UNION SELECT 1.5); drop table t1; create table t1 (a int, b int, c varchar(10)); create table t2 (a int); insert into t1 values (1,2,'a'),(2,3,'b'),(3,4,'c'); insert into t2 values (1),(2),(NULL); select a, (select a,b,c from t1 where t1.a=t2.a) = ROW(a,2,'a'),(select c from t1 where a=t2.a) from t2; select a, (select a,b,c from t1 where t1.a=t2.a) = ROW(a,3,'b'),(select c from t1 where a=t2.a) from t2; select a, (select a,b,c from t1 where t1.a=t2.a) = ROW(a,4,'c'),(select c from t1 where a=t2.a) from t2; drop table t1,t2; create table t1 (a int, b real, c varchar(10)); insert into t1 values (1, 1, 'a'), (2,2,'b'), (NULL, 2, 'b'); select ROW(1, 1, 'a') IN (select a,b,c from t1); select ROW(1, 2, 'a') IN (select a,b,c from t1); select ROW(1, 1, 'a') IN (select b,a,c from t1); select ROW(1, 1, 'a') IN (select a,b,c from t1 where a is not null); select ROW(1, 2, 'a') IN (select a,b,c from t1 where a is not null); select ROW(1, 1, 'a') IN (select b,a,c from t1 where a is not null); select ROW(1, 1, 'a') IN (select a,b,c from t1 where c='b' or c='a'); select ROW(1, 2, 'a') IN (select a,b,c from t1 where c='b' or c='a'); select ROW(1, 1, 'a') IN (select b,a,c from t1 where c='b' or c='a'); -- error 1235 select ROW(1, 1, 'a') IN (select b,a,c from t1 limit 2); drop table t1; create table t1 (a int); insert into t1 values (1); do @a:=(SELECT a from t1); select @a; set @a:=2; set @a:=(SELECT a from t1); select @a; drop table t1; -- error 1146 do (SELECT a from t1); -- error 1146 set @a:=(SELECT a from t1); CREATE TABLE t1 (a int, KEY(a)); HANDLER t1 OPEN; -- error 1149 HANDLER t1 READ a=((SELECT 1)); HANDLER t1 CLOSE; drop table t1; create table t1 (a int); create table t2 (b int); insert into t1 values (1),(2); insert into t2 values (1); select a from t1 where a in (select a from t1 where a in (select b from t2)); drop table t1, t2; create table t1 (a int, b int); create table t2 like t1; insert into t1 values (1,2),(1,3),(1,4),(1,5); insert into t2 values (1,2),(1,3); select * from t1 where row(a,b) in (select a,b from t2); drop table t1, t2; CREATE TABLE `t1` (`i` int(11) NOT NULL default '0',PRIMARY KEY (`i`)) TYPE=MyISAM CHARSET=latin1; INSERT INTO t1 VALUES (1); -- error 1111 UPDATE t1 SET i=i+1 WHERE i=(SELECT MAX(i)); drop table t1; #test of uncacheable subqueries CREATE TABLE t1 (a int(1)); EXPLAIN SELECT (SELECT RAND() FROM t1) FROM t1; EXPLAIN SELECT (SELECT ENCRYPT('test') FROM t1) FROM t1; EXPLAIN SELECT (SELECT BENCHMARK(1,1) FROM t1) FROM t1; drop table t1; CREATE TABLE `t1` ( `mot` varchar(30) character set latin1 NOT NULL default '', `topic` mediumint(8) unsigned NOT NULL default '0', `date` date NOT NULL default '0000-00-00', `pseudo` varchar(35) character set latin1 NOT NULL default '', PRIMARY KEY (`mot`,`pseudo`,`date`,`topic`), KEY `pseudo` (`pseudo`,`date`,`topic`), KEY `topic` (`topic`) ) TYPE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC; CREATE TABLE `t2` ( `mot` varchar(30) character set latin1 NOT NULL default '', `topic` mediumint(8) unsigned NOT NULL default '0', `date` date NOT NULL default '0000-00-00', `pseudo` varchar(35) character set latin1 NOT NULL default '', PRIMARY KEY (`mot`,`pseudo`,`date`,`topic`), KEY `pseudo` (`pseudo`,`date`,`topic`), KEY `topic` (`topic`) ) TYPE=MyISAM CHARSET=latin1 ROW_FORMAT=DYNAMIC; CREATE TABLE `t3` ( `numeropost` mediumint(8) unsigned NOT NULL auto_increment, `maxnumrep` int(10) unsigned NOT NULL default '0', PRIMARY KEY (`numeropost`), UNIQUE KEY `maxnumrep` (`maxnumrep`) ) TYPE=MyISAM CHARSET=latin1; INSERT INTO t1 VALUES ('joce','1','','joce'),('test','2','','test'); INSERT INTO t2 VALUES ('joce','1','','joce'),('test','2','','test'); INSERT INTO t3 VALUES (1,1); SELECT DISTINCT topic FROM t2 WHERE NOT EXISTS(SELECT * FROM t3 WHERE numeropost=topic); select * from t1; DELETE FROM t1 WHERE topic IN (SELECT DISTINCT topic FROM t2 WHERE NOT EXISTS(SELECT * FROM t3 WHERE numeropost=topic)); select * from t1; drop table t1, t2, t3; SELECT * FROM (SELECT 1 as a,(SELECT a)) a; CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT 1)) a; SHOW CREATE TABLE t1; drop table t1; CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT a)) a; SHOW CREATE TABLE t1; drop table t1; CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT a+0)) a; SHOW CREATE TABLE t1; drop table t1; CREATE TABLE t1 SELECT (SELECT 1 as a UNION SELECT 1+1 limit 1,1) as a; SHOW CREATE TABLE t1; drop table t1; create table t1 (a int); insert into t1 values (1), (2), (3); explain select a,(select (select rand() from t1 limit 1) from t1 limit 1) from t1; drop table t1;