select (select 2);
SELECT (SELECT 1) UNION SELECT (SELECT 2);
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);
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');
drop table searchconthardwarefr3;