select (select 2); SELECT (SELECT 1) UNION SELECT (SELECT 2); SELECT (SELECT (SELECT 0 UNION SELECT 0)); -- error 1245 SELECT (SELECT 1 FROM (SELECT 1) HAVING a=1) as a; -- error 1245 SELECT (SELECT 1 FROM (SELECT 1) HAVING b=1) as a,(SELECT 1 FROM (SELECT 1) HAVING a=1) as b; drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit; 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 a<t2.a*4 order by 1 desc limit 1), a from t2; 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; 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); 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 attend (patient_uq int, clinic_uq int, index i1 (clinic_uq)); create table clinic( uq int primary key, name char(25)); insert into clinic values(1,"Oblastnaia bolnitsa"),(2,"Bolnitsa Krasnogo Kresta"); insert into attend values (1,1),(1,2),(2,2),(1,3); select * from attend where exists (select * from clinic 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); drop table if exists inscrit; CREATE TABLE `inscrit` ( `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 inscrit (pseudo,email) VALUES ('joce','test'); INSERT INTO inscrit (pseudo,email) VALUES ('joce1','test1'); INSERT INTO inscrit (pseudo,email) VALUES ('2joce1','2test1'); EXPLAIN SELECT pseudo,(SELECT email FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce')) FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce'); -- error 1239 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo,email FROM inscrit WHERE pseudo='joce'); -- error 1239 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT * FROM inscrit WHERE pseudo='joce'); SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo='joce'); -- error 1240 SELECT pseudo FROM inscrit WHERE pseudo=(SELECT pseudo FROM inscrit WHERE pseudo LIKE '%joce%'); drop table if exists t1,t2,t3,t4,t5,attend,clinic,inscrit; drop table if exists searchconthardwarefr3; CREATE TABLE `searchconthardwarefr3` ( `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 searchconthardwarefr3 (topic,date,pseudo) VALUES ('43506','2002-10-02','joce'),('40143','2002-08-03','joce'); EXPLAIN SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03'; EXPLAIN SELECT (SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03'); SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03'; SELECT (SELECT DISTINCT date FROM searchconthardwarefr3 WHERE date='2002-08-03'); SELECT 1 FROM searchconthardwarefr3 WHERE 1=(SELECT 1 UNION SELECT 1) UNION ALL SELECT 1; -- error 1240 SELECT 1 FROM searchconthardwarefr3 WHERE 1=(SELECT 1 UNION ALL SELECT 1) UNION SELECT 1; EXPLAIN SELECT 1 FROM searchconthardwarefr3 WHERE 1=(SELECT 1 UNION SELECT 1); drop table searchconthardwarefr3; drop table if exists forumconthardwarefr7, searchconthardwarefr7; CREATE TABLE `forumconthardwarefr7` ( `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 forumconthardwarefr7 (numeropost,maxnumrep) VALUES (40143,1),(43506,2); CREATE TABLE `searchconthardwarefr7` ( `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 searchconthardwarefr7 (mot,topic,date,pseudo) VALUES ('joce','40143','2002-10-22','joce'), ('joce','43506','2002-10-22','joce'); select numeropost as a FROM forumconthardwarefr7 GROUP BY (SELECT 1 FROM forumconthardwarefr7 HAVING a=1); SELECT numeropost,maxnumrep FROM forumconthardwarefr7 WHERE exists (SELECT 1 FROM searchconthardwarefr7 WHERE (mot='joce') AND date >= '2002-10-21' AND forumconthardwarefr7.numeropost = searchconthardwarefr7.topic) ORDER BY maxnumrep DESC LIMIT 0, 20; -- error 1054 SELECT (SELECT 1) as a FROM (SELECT 1 FROM forumconthardwarefr7 HAVING a=1); drop table forumconthardwarefr7, searchconthardwarefr7; drop table if exists forumconthardwarefr7; CREATE TABLE `forumconthardwarefr7` ( `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 forumconthardwarefr7 (numeropost,maxnumrep) VALUES (1,0),(2,1); -- error 1240 select numeropost as a FROM forumconthardwarefr7 GROUP BY (SELECT 1 FROM forumconthardwarefr7 HAVING a=1); -- error 1240 select numeropost as a FROM forumconthardwarefr7 ORDER BY (SELECT 1 FROM forumconthardwarefr7 HAVING a=1); drop table if exists forumconthardwarefr7; drop table if exists iftest; CREATE TABLE iftest (field char(1) NOT NULL DEFAULT 'b'); INSERT INTO iftest VALUES (); -- error 1240 SELECT field FROM iftest WHERE 1=(SELECT 1 UNION ALL SELECT 1 FROM (SELECT 1) HAVING field='b'); drop table iftest; drop table if exists threadhardwarefr7; CREATE TABLE `threadhardwarefr7` ( `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 threadhardwarefr7 HAVING numreponse=a),numreponse FROM (SELECT * FROM threadhardwarefr7) as a; -- error 1054 SELECT numreponse, (SELECT numeropost FROM threadhardwarefr7 HAVING numreponse=a) FROM (SELECT * FROM threadhardwarefr7) as a; SELECT numreponse, (SELECT numeropost FROM threadhardwarefr7 HAVING numreponse=1) FROM (SELECT * FROM threadhardwarefr7) as a; INSERT INTO threadhardwarefr7 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test'); -- error 1240 EXPLAIN SELECT numreponse FROM threadhardwarefr7 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM threadhardwarefr7 WHERE numeropost='1'); EXPLAIN SELECT MAX(numreponse) FROM threadhardwarefr7 WHERE numeropost='1'; EXPLAIN SELECT numreponse FROM threadhardwarefr7 WHERE numeropost='1' AND numreponse=(SELECT MAX(numreponse) FROM threadhardwarefr7 WHERE numeropost='1'); drop table if exists threadhardwarefrtest7;