mariadb/mysql-test/suite/pbxt/r/subselect.result

drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t11,t12;
select (select 2);
(select 2)
2
explain extended select (select 2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1249	Select 2 was reduced during optimization
Note	1003	select 2 AS `(select 2)`
SELECT (SELECT 1) UNION SELECT (SELECT 2);
(SELECT 1)
1
2
explain extended SELECT (SELECT 1) UNION SELECT (SELECT 2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
NULL	UNION RESULT	<union1,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1249	Select 2 was reduced during optimization
Note	1249	Select 4 was reduced during optimization
Note	1003	select 1 AS `(SELECT 1)` union select 2 AS `(SELECT 2)`
SELECT (SELECT (SELECT 0 UNION SELECT 0));
(SELECT (SELECT 0 UNION SELECT 0))
0
explain extended SELECT (SELECT (SELECT 0 UNION SELECT 0));
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
4	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1249	Select 2 was reduced during optimization
Note	1003	select (select 0 union select 0) AS `(SELECT (SELECT 0 UNION SELECT 0))`
SELECT (SELECT 1 FROM (SELECT 1) as b HAVING a=1) as a;
ERROR 42S22: Reference 'a' not supported (forward reference in item list)
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;
ERROR 42S22: Reference 'b' not supported (forward reference in item list)
SELECT (SELECT 1),MAX(1) FROM (SELECT 1) as a;
(SELECT 1)	MAX(1)
1	1
SELECT (SELECT a) as a;
ERROR 42S22: Reference 'a' not supported (forward reference in item list)
EXPLAIN EXTENDED SELECT 1 FROM (SELECT 1 as a) as b  HAVING (SELECT a)=1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
Note	1276	Field or reference 'b.a' of SELECT #3 was resolved in SELECT #1
Note	1003	select 1 AS `1` from (select 1 AS `a`) `b` having (<expr_cache><1>((select 1)) = 1)
SELECT 1 FROM (SELECT 1 as a) as b HAVING (SELECT a)=1;
1
1
SELECT (SELECT 1), a;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT 1 as a FROM (SELECT 1) as b HAVING (SELECT a)=1;
a
1
SELECT 1 FROM (SELECT (SELECT a) b) c;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT * FROM (SELECT 1 as id) b WHERE id IN (SELECT * FROM (SELECT 1 as id) c ORDER BY id);
id
1
SELECT * FROM (SELECT 1) a  WHERE 1 IN (SELECT 1,1);
ERROR 21000: Operand should contain 1 column(s)
SELECT 1 IN (SELECT 1);
1 IN (SELECT 1)
1
SELECT 1 FROM (SELECT 1 as a) b WHERE 1 IN (SELECT (SELECT a));
1
1
select (SELECT 1 FROM (SELECT 1) a PROCEDURE ANALYSE(1));
ERROR HY000: Incorrect usage of PROCEDURE and subquery
SELECT 1 FROM (SELECT 1) a PROCEDURE ANALYSE((SELECT 1));
ERROR HY000: Incorrect parameters to procedure 'ANALYSE'
SELECT (SELECT 1) as a FROM (SELECT 1) b WHERE (SELECT a) IS NULL;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT (SELECT 1) as a FROM (SELECT 1) b WHERE (SELECT a) IS NOT NULL;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT (SELECT 1,2,3) = ROW(1,2,3);
(SELECT 1,2,3) = ROW(1,2,3)
1
SELECT (SELECT 1,2,3) = ROW(1,2,1);
(SELECT 1,2,3) = ROW(1,2,1)
0
SELECT (SELECT 1,2,3) < ROW(1,2,1);
(SELECT 1,2,3) < ROW(1,2,1)
0
SELECT (SELECT 1,2,3) > ROW(1,2,1);
(SELECT 1,2,3) > ROW(1,2,1)
1
SELECT (SELECT 1,2,3) = ROW(1,2,NULL);
(SELECT 1,2,3) = ROW(1,2,NULL)
NULL
SELECT ROW(1,2,3) = (SELECT 1,2,3);
ROW(1,2,3) = (SELECT 1,2,3)
1
SELECT ROW(1,2,3) = (SELECT 1,2,1);
ROW(1,2,3) = (SELECT 1,2,1)
0
SELECT ROW(1,2,3) < (SELECT 1,2,1);
ROW(1,2,3) < (SELECT 1,2,1)
0
SELECT ROW(1,2,3) > (SELECT 1,2,1);
ROW(1,2,3) > (SELECT 1,2,1)
1
SELECT ROW(1,2,3) = (SELECT 1,2,NULL);
ROW(1,2,3) = (SELECT 1,2,NULL)
NULL
SELECT (SELECT 1.5,2,'a') = ROW(1.5,2,'a');
(SELECT 1.5,2,'a') = ROW(1.5,2,'a')
1
SELECT (SELECT 1.5,2,'a') = ROW(1.5,2,'b');
(SELECT 1.5,2,'a') = ROW(1.5,2,'b')
0
SELECT (SELECT 1.5,2,'a') = ROW('1.5b',2,'b');
(SELECT 1.5,2,'a') = ROW('1.5b',2,'b')
0
Warnings:
Warning	1292	Truncated incorrect DOUBLE value: '1.5b'
SELECT (SELECT 'b',2,'a') = ROW(1.5,2,'a');
(SELECT 'b',2,'a') = ROW(1.5,2,'a')
0
SELECT (SELECT 1.5,2,'a') = ROW(1.5,'2','a');
(SELECT 1.5,2,'a') = ROW(1.5,'2','a')
1
SELECT (SELECT 1.5,'c','a') = ROW(1.5,2,'a');
(SELECT 1.5,'c','a') = ROW(1.5,2,'a')
0
SELECT (SELECT * FROM (SELECT 'test' a,'test' b) a);
ERROR 21000: Operand should contain 1 column(s)
SELECT 1 as a,(SELECT a+a) b,(SELECT b);
a	b	(SELECT b)
1	2	2
create table t1 (a int);
create table t2 (a int, b int);
create table t3 (a int);
create table t4 (a int not null, b int not null);
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 = a1) as a2, (select b from t2 where t2.b=a2) as a1;
ERROR 42S22: Reference 'a1' not supported (forward reference in item list)
select (select a from t1 where t1.a=t2.a), a from t2;
(select a from t1 where t1.a=t2.a)	a
NULL	1
2	2
select (select a from t1 where t1.a=t2.b), a from t2;
(select a from t1 where t1.a=t2.b)	a
NULL	1
NULL	2
select (select a from t1), a, (select 1 union select 2 limit 1) from t2;
(select a from t1)	a	(select 1 union select 2 limit 1)
2	1	1
2	2	1
select (select a from t3), a from t2;
(select a from t3)	a
NULL	1
NULL	2
select * from t2 where t2.a=(select a from t1);
a	b
2	7
insert into t3 values (6),(7),(3);
select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1);
a	b
1	7
2	7
(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;
a	b
1	7
2	7
3	8
(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);
a	b
1	7
2	7
4	8
3	8
explain extended (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);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using filesort
3	UNION	t4	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
4	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	
NULL	UNION RESULT	<union1,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	(select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`b` = (select `test`.`t3`.`a` from `test`.`t3` order by 1 desc limit 1))) union (select `test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t4` where (`test`.`t4`.`b` = (select (max(`test`.`t2`.`a`) * 4) from `test`.`t2`)) order by `a`)
select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
(select a from t3 where a<t2.a*4 order by 1 desc limit 1)	a
3	1
7	2
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 t3.a from t3 where a<8 order by 1 desc limit 1)	a
7	2
set @tmp_optimizer_switch=@@optimizer_switch;
set optimizer_switch='derived_merge=off,derived_with_keys=off';
explain extended 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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	<derived3>	ALL	NULL	NULL	NULL	NULL	2	100.00	
3	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using filesort
Warnings:
Note	1003	select (select `test`.`t3`.`a` from `test`.`t3` where (`test`.`t3`.`a` < 8) order by 1 desc limit 1) AS `(select t3.a from t3 where a<8 order by 1 desc limit 1)`,`tt`.`a` AS `a` from (select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` where (`test`.`t2`.`a` > 1)) `tt`
set optimizer_switch=@tmp_optimizer_switch;
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);
a
2
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);
a
2
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);
a
select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
b	(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2)
8	7.5000
8	4.5000
9	7.5000
explain extended select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	100.00	
2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	
3	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
Warnings:
Note	1276	Field or reference 'test.t4.a' of SELECT #3 was resolved in SELECT #1
Note	1003	select `test`.`t4`.`b` AS `b`,<expr_cache><`test`.`t4`.`a`>((select avg((`test`.`t2`.`a` + (select min(`test`.`t3`.`a`) from `test`.`t3` where (`test`.`t3`.`a` >= `test`.`t4`.`a`)))) from `test`.`t2`)) AS `(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2)` from `test`.`t4`
select * from t3 where exists (select * from t2 where t2.b=t3.a);
a
7
select * from t3 where not exists (select * from t2 where t2.b=t3.a);
a
6
3
select * from t3 where a in (select b from t2);
a
7
select * from t3 where a not in (select b from t2);
a
6
3
select * from t3 where a = some (select b from t2);
a
7
select * from t3 where a <> any (select b from t2);
a
6
3
select * from t3 where a = all (select b from t2);
a
7
select * from t3 where a <> all (select b from t2);
a
6
3
insert into t2 values (100, 5);
select * from t3 where a < any (select b from t2);
a
6
3
select * from t3 where a < all (select b from t2);
a
3
select * from t3 where a >= any (select b from t2);
a
6
7
explain extended select * from t3 where a >= any (select b from t2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
select * from t3 where a >= all (select b from t2);
a
7
delete from t2 where a=100;
select * from t3 where a in (select a,b from t2);
ERROR 21000: Operand should contain 1 column(s)
select * from t3 where a in (select * from t2);
ERROR 21000: Operand should contain 1 column(s)
insert into t4 values (12,7),(1,7),(10,9),(9,6),(7,6),(3,9),(1,10);
select b,max(a) as ma from t4 group by b having b < (select max(t2.a) from t2 where t2.b=t4.b);
b	ma
insert into t2 values (2,10);
select b,max(a) as ma from t4 group by b having ma < (select max(t2.a) from t2 where t2.b=t4.b);
b	ma
10	1
delete from t2 where a=2 and b=10;
select b,max(a) as ma from t4 group by b having b >= (select max(t2.a) from t2 where t2.b=t4.b);
b	ma
7	12
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;
(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)	a
NULL	1
2	2
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;
(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)	a
NULL	1
2	2
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;
(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)	a
NULL	1
2	2
explain extended select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	#	100.00	
2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	#	100.00	Using where
3	DEPENDENT UNION	t5	ALL	NULL	NULL	NULL	NULL	#	100.00	Using where
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	#	NULL	
Warnings:
Note	1276	Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1
Note	1276	Field or reference 'test.t2.a' of SELECT #3 was resolved in SELECT #1
Note	1003	select <expr_cache><`test`.`t2`.`a`>((select `test`.`t1`.`a` from `test`.`t1` where (`test`.`t1`.`a` = `test`.`t2`.`a`) union select `test`.`t5`.`a` from `test`.`t5` where (`test`.`t5`.`a` = `test`.`t2`.`a`))) AS `(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)`,`test`.`t2`.`a` AS `a` from `test`.`t2`
select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2;
ERROR 21000: Subquery returns more than 1 row
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);
patient_uq	clinic_uq
1	1
1	2
2	2
explain extended select * from t6 where exists (select * from t7 where uq = clinic_uq);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t6	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
2	DEPENDENT SUBQUERY	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.clinic_uq	1	100.00	Using index
Warnings:
Note	1276	Field or reference 'test.t6.clinic_uq' of SELECT #2 was resolved in SELECT #1
Note	1003	select `test`.`t6`.`patient_uq` AS `patient_uq`,`test`.`t6`.`clinic_uq` AS `clinic_uq` from `test`.`t6` where <expr_cache><`test`.`t6`.`clinic_uq`>(exists(select 1 from `test`.`t7` where (`test`.`t7`.`uq` = `test`.`t6`.`clinic_uq`)))
select * from t1 where a= (select a from t2,t4 where t2.b=t4.b);
ERROR 23000: Column 'a' in field list is ambiguous
drop table 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);
a	b
W	1732-02-22
SELECT * FROM t2 WHERE b = (SELECT MIN(b) FROM t2);
a	b
W	1
SELECT * FROM t3 WHERE b = (SELECT MIN(b) FROM t3);
a	b
W	a
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`)
) ENGINE=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 EXTENDED 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');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where; Using index
4	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
2	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using where
3	SUBQUERY	t8	const	PRIMARY	PRIMARY	37	const	1	100.00	Using index
Warnings:
Note	1003	select `test`.`t8`.`pseudo` AS `pseudo`,(select `test`.`t8`.`email` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))) AS `(SELECT email FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce'))` from `test`.`t8` where (`test`.`t8`.`pseudo` = (select 'joce' from `test`.`t8` where 1))
SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo,email FROM
t8 WHERE pseudo='joce');
ERROR 21000: Operand should contain 1 column(s)
SELECT pseudo FROM t8 WHERE pseudo=(SELECT * FROM t8 WHERE
pseudo='joce');
ERROR 21000: Operand should contain 1 column(s)
SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo='joce');
pseudo
joce
SELECT pseudo FROM t8 WHERE pseudo=(SELECT pseudo FROM t8 WHERE pseudo LIKE '%joce%');
ERROR 21000: Subquery returns more than 1 row
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8;
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`)
) ENGINE=MyISAM ROW_FORMAT=DYNAMIC;
INSERT INTO t1 (topic,date,pseudo) VALUES
('43506','2002-10-02','joce'),('40143','2002-08-03','joce');
EXPLAIN EXTENDED SELECT DISTINCT date FROM t1 WHERE date='2002-08-03';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	NULL	PRIMARY	43	NULL	2	100.00	Using where; Using index
Warnings:
Note	1003	select distinct `test`.`t1`.`date` AS `date` from `test`.`t1` where (`test`.`t1`.`date` = '2002-08-03')
EXPLAIN EXTENDED SELECT (SELECT DISTINCT date FROM t1 WHERE date='2002-08-03');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
2	SUBQUERY	t1	index	NULL	PRIMARY	43	NULL	2	100.00	Using where; Using index
Warnings:
Note	1003	select (select distinct `test`.`t1`.`date` from `test`.`t1` where (`test`.`t1`.`date` = '2002-08-03')) AS `(SELECT DISTINCT date FROM t1 WHERE date='2002-08-03')`
SELECT DISTINCT date FROM t1 WHERE date='2002-08-03';
date
2002-08-03
SELECT (SELECT DISTINCT date FROM t1 WHERE date='2002-08-03');
(SELECT DISTINCT date FROM t1 WHERE date='2002-08-03')
2002-08-03
SELECT 1 FROM t1 WHERE 1=(SELECT 1 UNION SELECT 1) UNION ALL SELECT 1;
1
1
1
1
SELECT 1 FROM t1 WHERE 1=(SELECT 1 UNION ALL SELECT 1) UNION SELECT 1;
ERROR 21000: Subquery returns more than 1 row
EXPLAIN EXTENDED SELECT 1 FROM t1 WHERE 1=(SELECT 1 UNION SELECT 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	topic	3	NULL	2	100.00	Using index
2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	select 1 AS `1` from `test`.`t1` where (1 = (select 1 union select 1))
drop table t1;
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`)
) ENGINE=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`)
) ENGINE=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);
a
40143
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;
numeropost	maxnumrep
43506	2
40143	1
SELECT (SELECT 1) as a FROM (SELECT 1 FROM t1 HAVING a=1) b;
ERROR 42S22: Unknown column 'a' in 'having clause'
SELECT 1 IN (SELECT 1 FROM t2 HAVING a);
ERROR 42S22: Unknown column 'a' in 'having clause'
SELECT * from t2 where topic IN (SELECT topic FROM t2 GROUP BY topic);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
joce	43506	2002-10-22	joce
SELECT * from t2 where topic IN (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100);
mot	topic	date	pseudo
SELECT * from t2 where topic IN (SELECT SUM(topic) FROM t1);
mot	topic	date	pseudo
SELECT * from t2 where topic = any (SELECT topic FROM t2 GROUP BY topic);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
joce	43506	2002-10-22	joce
SELECT * from t2 where topic = any (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100);
mot	topic	date	pseudo
SELECT * from t2 where topic = any (SELECT SUM(topic) FROM t1);
mot	topic	date	pseudo
SELECT * from t2 where topic = all (SELECT topic FROM t2 GROUP BY topic);
mot	topic	date	pseudo
SELECT * from t2 where topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
joce	43506	2002-10-22	joce
SELECT *, topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100) from t2;
mot	topic	date	pseudo	topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 4100)
joce	40143	2002-10-22	joce	1
joce	43506	2002-10-22	joce	1
SELECT * from t2 where topic = all (SELECT SUM(topic) FROM t2);
mot	topic	date	pseudo
SELECT * from t2 where topic <> any (SELECT SUM(topic) FROM t2);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
joce	43506	2002-10-22	joce
SELECT * from t2 where topic IN (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
SELECT * from t2 where topic = any (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
SELECT * from t2 where topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000);
mot	topic	date	pseudo
joce	40143	2002-10-22	joce
SELECT *, topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000) from t2;
mot	topic	date	pseudo	topic = all (SELECT topic FROM t2 GROUP BY topic HAVING topic < 41000)
joce	40143	2002-10-22	joce	1
joce	43506	2002-10-22	joce	0
drop table t1,t2;
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`)
) ENGINE=MyISAM ROW_FORMAT=FIXED;
INSERT INTO t1 (numeropost,maxnumrep) VALUES (1,0),(2,1);
select numeropost as a FROM t1 GROUP BY (SELECT 1 FROM t1 HAVING a=1);
ERROR 21000: Subquery returns more than 1 row
select numeropost as a FROM t1 ORDER BY (SELECT 1 FROM t1 HAVING a=1);
ERROR 21000: Subquery returns more than 1 row
drop table t1;
create table t1 (a int);
insert into t1 values (1),(2),(3);
(select * from t1) union (select * from t1) order by (select a from t1 limit 1);
a
1
2
3
drop table t1;
CREATE TABLE t1 (field char(1) NOT NULL DEFAULT 'b');
INSERT INTO t1 VALUES ();
SELECT field FROM t1 WHERE 1=(SELECT 1 UNION ALL SELECT 1 FROM (SELECT 1) a HAVING field='b');
ERROR 21000: Subquery returns more than 1 row
drop table t1;
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`)
) ENGINE=MyISAM;
SELECT (SELECT numeropost FROM t1 HAVING numreponse=a),numreponse FROM (SELECT * FROM t1) as a;
ERROR 42S22: Reference 'numreponse' not supported (forward reference in item list)
SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=a) FROM (SELECT * FROM t1) as a;
ERROR 42S22: Unknown column 'a' in 'having clause'
SELECT numreponse, (SELECT numeropost FROM t1 HAVING numreponse=1) FROM (SELECT * FROM t1) as a;
numreponse	(SELECT numeropost FROM t1 HAVING numreponse=1)
INSERT INTO t1 (numeropost,numreponse,pseudo) VALUES (1,1,'joce'),(1,2,'joce'),(1,3,'test');
EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
2	SUBQUERY	t1	ref	PRIMARY	PRIMARY	3	const	2	100.00	Using index
Warnings:
Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select 1 from `test`.`t1` where (`test`.`t1`.`numeropost` = '1'))))
SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT 1 FROM t1 WHERE numeropost='1');
ERROR 21000: Subquery returns more than 1 row
EXPLAIN EXTENDED SELECT MAX(numreponse) FROM t1 WHERE numeropost='1';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
Warnings:
Note	1003	select max(`test`.`t1`.`numreponse`) AS `MAX(numreponse)` from `test`.`t1` where (`test`.`t1`.`numeropost` = '1')
EXPLAIN EXTENDED SELECT numreponse FROM t1 WHERE numeropost='1' AND numreponse=(SELECT MAX(numreponse) FROM t1 WHERE numeropost='1');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	const	PRIMARY,numreponse	PRIMARY	7	const,const	1	100.00	Using where; Using index
2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
Warnings:
Note	1003	select `test`.`t1`.`numreponse` AS `numreponse` from `test`.`t1` where ((`test`.`t1`.`numeropost` = '1') and (`test`.`t1`.`numreponse` = (select max(`test`.`t1`.`numreponse`) from `test`.`t1` where (`test`.`t1`.`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;
1
1
drop table t1;
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;
a	b
0	10
1	11
2	12
update t1 set b= (select b from t1);
ERROR HY000: You can't specify target table 't1' for update in FROM clause
update t1 set b= (select b from t2);
ERROR 21000: Subquery returns more than 1 row
update t1 set b= (select b from t2 where t1.a = t2.a);
select * from t1;
a	b
0	NULL
1	21
2	22
drop table t1, t2;
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;
a	b
0	10
1	11
2	12
select * from t1 where b = (select b from t2 where t1.a = t2.a);
a	b
2	12
delete from t1 where b = (select b from t1);
ERROR HY000: You can't specify target table 't1' for update in FROM clause
delete from t1 where b = (select b from t2);
ERROR 21000: Subquery returns more than 1 row
delete from t1 where b = (select b from t2 where t1.a = t2.a);
select * from t1;
a	b
0	10
1	11
drop table t1, t2;
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;
a	b
0	10
1	11
2	12
select * from t12;
a	b
33	10
22	11
2	12
delete t11.*, t12.* from t11,t12 where t11.a = t12.a and t11.b = (select b from t12 where t11.a = t12.a);
ERROR HY000: You can't specify target table 't12' for update in FROM clause
delete t11.*, t12.* from t11,t12 where t11.a = t12.a and t11.b = (select b from t2);
ERROR 21000: Subquery returns more than 1 row
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;
a	b
0	10
1	11
select * from t12;
a	b
33	10
22	11
drop table t11, t12, t2;
CREATE TABLE t1 (x int);
create table t2 (a int);
create table t3 (b int);
insert into t2 values (1);
insert into t3 values (1),(2);
INSERT INTO t1 (x) VALUES ((SELECT x FROM t1));
ERROR HY000: You can't specify target table 't1' for update in FROM clause
INSERT INTO t1 (x) VALUES ((SELECT b FROM t3));
ERROR 21000: Subquery returns more than 1 row
INSERT INTO t1 (x) VALUES ((SELECT a FROM t2));
select * from t1;
x
1
insert into t2 values (1);
INSERT INTO t1 (x) VALUES ((SELECT SUM(a) FROM t2));
select * from t1;
x
1
2
INSERT INTO t1 (x) select (SELECT SUM(a)+1 FROM t2) FROM t2;
select * from t1;
x
1
2
3
3
INSERT INTO t1 (x) select (SELECT SUM(x)+2 FROM t1) FROM t2;
select * from t1;
x
1
2
3
3
11
11
INSERT INTO t1 (x) VALUES ((SELECT SUM(x) FROM t2));
ERROR 42S22: Unknown column 'x' in 'field list'
INSERT INTO t1 (x) VALUES ((SELECT SUM(a) FROM t2));
select * from t1;
x
1
2
3
3
11
11
2
drop table t1, t2, t3;
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;
x	y
replace into t1 (x, y) VALUES ((SELECT x FROM t1), (SELECT a+1 FROM t2));
ERROR HY000: You can't specify target table 't1' for update in FROM clause
replace into t1 (x, y) VALUES ((SELECT a FROM t3), (SELECT a+1 FROM t2));
ERROR 21000: Subquery returns more than 1 row
replace into t1 (x, y) VALUES ((SELECT a FROM t2), (SELECT a+1 FROM t2));
select * from t1;
x	y
1	2
replace into t1 (x, y) VALUES ((SELECT a FROM t2), (SELECT a+2 FROM t2));
select * from t1;
x	y
1	3
replace into t1 (x, y) VALUES ((SELECT a+3 FROM t2), (SELECT a FROM t2));
select * from t1 order by x;
x	y
1	3
4	1
replace into t1 (x, y) VALUES ((SELECT a+3 FROM t2), (SELECT a+1 FROM t2));
select * from t1 order by x;
x	y
1	3
4	2
replace LOW_PRIORITY into t1 (x, y) VALUES ((SELECT a+1 FROM t2), (SELECT a FROM t2));
select * from t1 order by x;
x	y
1	3
2	1
4	2
drop table t1, t2, t3;
SELECT * FROM (SELECT 1) b WHERE 1 IN (SELECT *);
ERROR HY000: No tables used
CREATE TABLE t2 (id int(11) default NULL, KEY id (id)) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t2 VALUES (1),(2);
SELECT * FROM t2 WHERE id IN (SELECT 1);
id
1
EXPLAIN EXTENDED SELECT * FROM t2 WHERE id IN (SELECT 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	ref	id	id	5	const	1	100.00	Using index
Warnings:
Note	1249	Select 2 was reduced during optimization
Note	1003	select `test`.`t2`.`id` AS `id` from `test`.`t2` where (`test`.`t2`.`id` = 1)
SELECT * FROM t2 WHERE id IN (SELECT 1 UNION SELECT 3);
id
1
SELECT * FROM t2 WHERE id IN (SELECT 1+(select 1));
id
2
EXPLAIN EXTENDED SELECT * FROM t2 WHERE id IN (SELECT 1+(select 1));
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	ref	id	id	5	const	1	100.00	Using index
Warnings:
Note	1249	Select 3 was reduced during optimization
Note	1249	Select 2 was reduced during optimization
Note	1003	select `test`.`t2`.`id` AS `id` from `test`.`t2` where (`test`.`t2`.`id` = (1 + 1))
EXPLAIN EXTENDED SELECT * FROM t2 WHERE id IN (SELECT 1 UNION SELECT 3);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	NULL	id	5	NULL	2	100.00	Using where; Using index
2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
3	DEPENDENT UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	select `test`.`t2`.`id` AS `id` from `test`.`t2` where <expr_cache><`test`.`t2`.`id`>(<in_optimizer>(`test`.`t2`.`id`,<exists>(select 1 having (<cache>(`test`.`t2`.`id`) = <ref_null_helper>(1)) union select 3 having (<cache>(`test`.`t2`.`id`) = <ref_null_helper>(3)))))
SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 3);
id
SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 2);
id
2
INSERT INTO t2 VALUES ((SELECT * FROM t2));
ERROR HY000: You can't specify target table 't2' for update in FROM clause
INSERT INTO t2 VALUES ((SELECT id FROM t2));
ERROR HY000: You can't specify target table 't2' for update in FROM clause
SELECT * FROM t2;
id
1
2
CREATE TABLE t1 (id int(11) default NULL, KEY id (id)) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 values (1),(1);
UPDATE t2 SET id=(SELECT * FROM t1);
ERROR 21000: Subquery returns more than 1 row
drop table t2, t1;
create table t1 (a int);
insert into t1 values (1),(2),(3);
select 1 IN (SELECT * from t1);
1 IN (SELECT * from t1)
1
select 10 IN (SELECT * from t1);
10 IN (SELECT * from t1)
0
select NULL IN (SELECT * from t1);
NULL IN (SELECT * from t1)
NULL
update t1 set a=NULL where a=2;
select 1 IN (SELECT * from t1);
1 IN (SELECT * from t1)
1
select 3 IN (SELECT * from t1);
3 IN (SELECT * from t1)
1
select 10 IN (SELECT * from t1);
10 IN (SELECT * from t1)
NULL
select 1 > ALL (SELECT * from t1);
1 > ALL (SELECT * from t1)
0
select 10 > ALL (SELECT * from t1);
10 > ALL (SELECT * from t1)
NULL
select 1 > ANY (SELECT * from t1);
1 > ANY (SELECT * from t1)
NULL
select 10 > ANY (SELECT * from t1);
10 > ANY (SELECT * from t1)
1
drop table t1;
create table t1 (a varchar(20));
insert into t1 values ('A'),('BC'),('DEF');
select 'A' IN (SELECT * from t1);
'A' IN (SELECT * from t1)
1
select 'XYZS' IN (SELECT * from t1);
'XYZS' IN (SELECT * from t1)
0
select NULL IN (SELECT * from t1);
NULL IN (SELECT * from t1)
NULL
update t1 set a=NULL where a='BC';
select 'A' IN (SELECT * from t1);
'A' IN (SELECT * from t1)
1
select 'DEF' IN (SELECT * from t1);
'DEF' IN (SELECT * from t1)
1
select 'XYZS' IN (SELECT * from t1);
'XYZS' IN (SELECT * from t1)
NULL
select 'A' > ALL (SELECT * from t1);
'A' > ALL (SELECT * from t1)
0
select 'XYZS' > ALL (SELECT * from t1);
'XYZS' > ALL (SELECT * from t1)
NULL
select 'A' > ANY (SELECT * from t1);
'A' > ANY (SELECT * from t1)
NULL
select 'XYZS' > ANY (SELECT * from t1);
'XYZS' > ANY (SELECT * from t1)
1
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);
1.5 IN (SELECT * from t1)
1
select 10.5 IN (SELECT * from t1);
10.5 IN (SELECT * from t1)
0
select NULL IN (SELECT * from t1);
NULL IN (SELECT * from t1)
NULL
update t1 set a=NULL where a=2.5;
select 1.5 IN (SELECT * from t1);
1.5 IN (SELECT * from t1)
1
select 3.5 IN (SELECT * from t1);
3.5 IN (SELECT * from t1)
1
select 10.5 IN (SELECT * from t1);
10.5 IN (SELECT * from t1)
NULL
select 1.5 > ALL (SELECT * from t1);
1.5 > ALL (SELECT * from t1)
0
select 10.5 > ALL (SELECT * from t1);
10.5 > ALL (SELECT * from t1)
NULL
select 1.5 > ANY (SELECT * from t1);
1.5 > ANY (SELECT * from t1)
NULL
select 10.5 > ANY (SELECT * from t1);
10.5 > ANY (SELECT * from t1)
1
explain extended select (select a+1) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
Warnings:
Note	1276	Field or reference 'test.t1.a' of SELECT #2 was resolved in SELECT #1
Note	1249	Select 2 was reduced during optimization
Note	1003	select (`test`.`t1`.`a` + 1) AS `(select a+1)` from `test`.`t1`
select (select a+1) from t1;
(select a+1)
2.5
4.5
NULL
drop table t1;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
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;
a	t1.a in (select t2.a from t2)
1	1
2	1
3	1
4	0
explain extended SELECT t1.a, t1.a in (select t2.a from t2) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
2	DEPENDENT SUBQUERY	t2	index_subquery	a	a	5	func	2	100.00	Using index
Warnings:
Note	1003	select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL having <is_not_null_test>(`test`.`t2`.`a`))))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
CREATE TABLE t3 (a int(11) default '0');
INSERT INTO t3 VALUES (1),(2),(3);
SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
a	t1.a in (select t2.a from t2,t3 where t3.a=t2.a)
1	1
2	1
3	1
4	0
explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
2	DEPENDENT SUBQUERY	t2	ref_or_null	a	a	5	func	2	100.00	Using where; Using index
2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
Warnings:
Note	1003	select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select `test`.`t2`.`a` from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
drop table t1,t2,t3;
create table t1 (a float);
select 10.5 IN (SELECT * from t1 LIMIT 1);
ERROR 42000: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
select 10.5 IN (SELECT * from t1 LIMIT 1 UNION SELECT 1.5);
ERROR 42000: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
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;
a	(select a,b,c from t1 where t1.a=t2.a) = ROW(a,2,'a')	(select c from t1 where a=t2.a)
1	1	a
2	0	b
NULL	NULL	NULL
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;
a	(select a,b,c from t1 where t1.a=t2.a) = ROW(a,3,'b')	(select c from t1 where a=t2.a)
1	0	a
2	1	b
NULL	NULL	NULL
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;
a	(select a,b,c from t1 where t1.a=t2.a) = ROW(a,4,'c')	(select c from t1 where a=t2.a)
1	0	a
2	0	b
NULL	NULL	NULL
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);
ROW(1, 1, 'a') IN (select a,b,c from t1)
1
select ROW(1, 2, 'a') IN (select a,b,c from t1);
ROW(1, 2, 'a') IN (select a,b,c from t1)
0
select ROW(1, 1, 'a') IN (select b,a,c from t1);
ROW(1, 1, 'a') IN (select b,a,c from t1)
1
select ROW(1, 1, 'a') IN (select a,b,c from t1 where a is not null);
ROW(1, 1, 'a') IN (select a,b,c from t1 where a is not null)
1
select ROW(1, 2, 'a') IN (select a,b,c from t1 where a is not null);
ROW(1, 2, 'a') IN (select a,b,c from t1 where a is not null)
0
select ROW(1, 1, 'a') IN (select b,a,c from t1 where a is not null);
ROW(1, 1, 'a') IN (select b,a,c from t1 where a is not null)
1
select ROW(1, 1, 'a') IN (select a,b,c from t1 where c='b' or c='a');
ROW(1, 1, 'a') IN (select a,b,c from t1 where c='b' or c='a')
1
select ROW(1, 2, 'a') IN (select a,b,c from t1 where c='b' or c='a');
ROW(1, 2, 'a') IN (select a,b,c from t1 where c='b' or c='a')
0
select ROW(1, 1, 'a') IN (select b,a,c from t1 where c='b' or c='a');
ROW(1, 1, 'a') IN (select b,a,c from t1 where c='b' or c='a')
1
select ROW(1, 1, 'a') IN (select b,a,c from t1 limit 2);
ERROR 42000: This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'
drop table t1;
create table t1 (a int);
insert into t1 values (1);
do @a:=(SELECT a from t1);
select @a;
@a
1
set @a:=2;
set @a:=(SELECT a from t1);
select @a;
@a
1
drop table t1;
do (SELECT a from t1);
ERROR 42S02: Table 'test.t1' doesn't exist
set @a:=(SELECT a from t1);
ERROR 42S02: Table 'test.t1' doesn't exist
CREATE TABLE t1 (a int, KEY(a));
HANDLER t1 OPEN;
HANDLER t1 READ a=((SELECT 1));
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT 1))' at line 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));
a
1
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);
a	b
1	2
1	3
drop table t1, t2;
CREATE TABLE `t1` (`i` int(11) NOT NULL default '0',PRIMARY KEY  (`i`)) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 VALUES (1);
UPDATE t1 SET i=i+1 WHERE i=(SELECT MAX(i));
select * from t1;
i
2
drop table t1;
CREATE TABLE t1 (a int(1));
EXPLAIN EXTENDED SELECT (SELECT RAND() FROM t1) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	
2	UNCACHEABLE SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select (select rand() from `test`.`t1`) AS `(SELECT RAND() FROM t1)` from `test`.`t1`
EXPLAIN EXTENDED SELECT (SELECT ENCRYPT('test') FROM t1) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	
2	UNCACHEABLE SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select (select encrypt('test') from `test`.`t1`) AS `(SELECT ENCRYPT('test') FROM t1)` from `test`.`t1`
EXPLAIN EXTENDED SELECT (SELECT BENCHMARK(1,1) FROM t1) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	
2	UNCACHEABLE SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select (select benchmark(1,1) from `test`.`t1`) AS `(SELECT BENCHMARK(1,1) FROM t1)` from `test`.`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`)
) ENGINE=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`)
) ENGINE=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`)
) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 VALUES ('joce','1','','joce'),('test','2','','test');
Warnings:
Warning	1265	Data truncated for column 'date' at row 1
Warning	1265	Data truncated for column 'date' at row 2
INSERT INTO t2 VALUES ('joce','1','','joce'),('test','2','','test');
Warnings:
Warning	1265	Data truncated for column 'date' at row 1
Warning	1265	Data truncated for column 'date' at row 2
INSERT INTO t3 VALUES (1,1);
SELECT DISTINCT topic FROM t2 WHERE NOT EXISTS(SELECT * FROM t3 WHERE
numeropost=topic);
topic
2
select * from t1;
mot	topic	date	pseudo
joce	1	0000-00-00	joce
test	2	0000-00-00	test
DELETE FROM t1 WHERE topic IN (SELECT DISTINCT topic FROM t2 WHERE NOT
EXISTS(SELECT * FROM t3 WHERE numeropost=topic));
select * from t1;
mot	topic	date	pseudo
joce	1	0000-00-00	joce
drop table t1, t2, t3;
SELECT * FROM (SELECT 1 as a,(SELECT a)) a;
a	(SELECT a)
1	1
CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT 1)) a;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(1) NOT NULL DEFAULT '0',
  `(SELECT 1)` int(1) NOT NULL DEFAULT '0'
) ENGINE=PBXT DEFAULT CHARSET=latin1
drop table t1;
CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT a)) a;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(1) NOT NULL DEFAULT '0',
  `(SELECT a)` int(1) NOT NULL DEFAULT '0'
) ENGINE=PBXT DEFAULT CHARSET=latin1
drop table t1;
CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT a+0)) a;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(1) NOT NULL DEFAULT '0',
  `(SELECT a+0)` int(3) NOT NULL DEFAULT '0'
) ENGINE=PBXT DEFAULT CHARSET=latin1
drop table t1;
CREATE TABLE t1 SELECT (SELECT 1 as a UNION SELECT 1+1 limit 1,1) as a;
select * from t1;
a
2
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` bigint(20) NOT NULL DEFAULT '0'
) ENGINE=PBXT DEFAULT CHARSET=latin1
drop table t1;
create table t1 (a int);
insert into t1 values (1), (2), (3);
explain extended select a,(select (select rand() from t1 limit 1)  from t1 limit 1)
from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
2	UNCACHEABLE SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
3	UNCACHEABLE SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
Warnings:
Note	1003	select `test`.`t1`.`a` AS `a`,(select (select rand() from `test`.`t1` limit 1) from `test`.`t1` limit 1) AS `(select (select rand() from t1 limit 1)  from t1 limit 1)` from `test`.`t1`
drop table t1;
select t1.Continent, t2.Name, t2.Population from t1 LEFT JOIN t2 ON t1.Code = t2.Country  where t2.Population IN (select max(t2.Population) AS Population from t2, t1 where t2.Country = t1.Code group by Continent);
ERROR 42S02: Table 'test.t1' doesn't exist
CREATE TABLE t1 (
ID int(11) NOT NULL auto_increment,
name char(35) NOT NULL default '',
t2 char(3) NOT NULL default '',
District char(20) NOT NULL default '',
Population int(11) NOT NULL default '0',
PRIMARY KEY  (ID)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (130,'Sydney','AUS','New South Wales',3276207);
INSERT INTO t1 VALUES (131,'Melbourne','AUS','Victoria',2865329);
INSERT INTO t1 VALUES (132,'Brisbane','AUS','Queensland',1291117);
CREATE TABLE t2 (
Code char(3) NOT NULL default '',
Name char(52) NOT NULL default '',
Continent enum('Asia','Europe','North America','Africa','Oceania','Antarctica','South America') NOT NULL default 'Asia',
Region char(26) NOT NULL default '',
SurfaceArea float(10,2) NOT NULL default '0.00',
IndepYear smallint(6) default NULL,
Population int(11) NOT NULL default '0',
LifeExpectancy float(3,1) default NULL,
GNP float(10,2) default NULL,
GNPOld float(10,2) default NULL,
LocalName char(45) NOT NULL default '',
GovernmentForm char(45) NOT NULL default '',
HeadOfState char(60) default NULL,
Capital int(11) default NULL,
Code2 char(2) NOT NULL default '',
PRIMARY KEY  (Code)
) ENGINE=MyISAM;
INSERT INTO t2 VALUES ('AUS','Australia','Oceania','Australia and New Zealand',7741220.00,1901,18886000,79.8,351182.00,392911.00,'Australia','Constitutional Monarchy, Federation','Elisabeth II',135,'AU');
INSERT INTO t2 VALUES ('AZE','Azerbaijan','Asia','Middle East',86600.00,1991,7734000,62.9,4127.00,4100.00,'Azärbaycan','Federal Republic','Heydär Äliyev',144,'AZ');
select t2.Continent, t1.Name, t1.Population from t2 LEFT JOIN t1 ON t2.Code = t1.t2  where t1.Population IN (select max(t1.Population) AS Population from t1, t2 where t1.t2 = t2.Code group by Continent);
Continent	Name	Population
Oceania	Sydney	3276207
drop table t1, t2;
CREATE TABLE `t1` (
`id` mediumint(8) unsigned NOT NULL auto_increment,
`pseudo` varchar(35) character set latin1 NOT NULL default '',
PRIMARY KEY  (`id`),
UNIQUE KEY `pseudo` (`pseudo`)
) ENGINE=MyISAM PACK_KEYS=1 ROW_FORMAT=DYNAMIC;
INSERT INTO t1 (pseudo) VALUES ('test');
SELECT 0 IN (SELECT 1 FROM t1 a);
0 IN (SELECT 1 FROM t1 a)
0
EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
Warnings:
Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
INSERT INTO t1 (pseudo) VALUES ('test1');
SELECT 0 IN (SELECT 1 FROM t1 a);
0 IN (SELECT 1 FROM t1 a)
0
EXPLAIN EXTENDED SELECT 0 IN (SELECT 1 FROM t1 a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
2	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
Warnings:
Note	1003	select <in_optimizer>(0,<exists>(select 1 from `test`.`t1` `a` where (0 = 1))) AS `0 IN (SELECT 1 FROM t1 a)`
drop table t1;
CREATE TABLE `t1` (
`i` int(11) NOT NULL default '0',
PRIMARY KEY  (`i`)
) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 VALUES (1);
UPDATE t1 SET i=i+(SELECT MAX(i) FROM (SELECT 1) t) WHERE i=(SELECT MAX(i));
UPDATE t1 SET i=i+1 WHERE i=(SELECT MAX(i));
UPDATE t1 SET t.i=i+(SELECT MAX(i) FROM (SELECT 1) t);
ERROR 42S22: Unknown column 't.i' in 'field list'
select * from t1;
i
3
drop table t1;
CREATE TABLE t1 (
id int(11) default NULL
) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 VALUES (1),(1),(2),(2),(1),(3);
CREATE TABLE t2 (
id int(11) default NULL,
name varchar(15) default NULL
) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t2 VALUES (4,'vita'), (1,'vita'), (2,'vita'), (1,'vita');
update t1, t2 set t2.name='lenka' where t2.id in (select id from t1);
select * from t2;
id	name
4	vita
1	lenka
2	lenka
1	lenka
drop table t1,t2;
create table t1 (a int, unique index indexa (a));
insert into t1 values (-1), (-4), (-2), (NULL);
select -10 IN (select a from t1 FORCE INDEX (indexa));
-10 IN (select a from t1 FORCE INDEX (indexa))
NULL
drop table t1;
create table t1 (id int not null auto_increment primary key, salary int, key(salary));
insert into t1 (salary) values (100),(1000),(10000),(10),(500),(5000),(50000);
explain extended SELECT id FROM t1 where salary = (SELECT MAX(salary) FROM t1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ref	salary	salary	5	const	0	0.00	Using where
2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Select tables optimized away
Warnings:
Note	1003	select `test`.`t1`.`id` AS `id` from `test`.`t1` where (`test`.`t1`.`salary` = (select max(`test`.`t1`.`salary`) from `test`.`t1`))
drop table t1;
CREATE TABLE t1 (
ID int(10) unsigned NOT NULL auto_increment,
SUB_ID int(3) unsigned NOT NULL default '0',
REF_ID int(10) unsigned default NULL,
REF_SUB int(3) unsigned default '0',
PRIMARY KEY (ID,SUB_ID),
UNIQUE KEY t1_PK (ID,SUB_ID),
KEY t1_FK (REF_ID,REF_SUB),
KEY t1_REFID (REF_ID)
) ENGINE=MyISAM CHARSET=cp1251;
INSERT INTO t1 VALUES (1,0,NULL,NULL),(2,0,NULL,NULL);
SELECT DISTINCT REF_ID FROM t1 WHERE ID= (SELECT DISTINCT REF_ID FROM t1 WHERE ID=2);
REF_ID
DROP TABLE t1;
create table t1 (a int, b int);
create table t2 (a int, b int);
insert into t1 values (1,0), (2,0), (3,0);
insert into t2 values (1,1), (2,1), (3,1), (2,2);
update ignore t1 set b=(select b from t2 where t1.a=t2.a);
Warnings:
Warning	1242	Subquery returns more than 1 row
select * from t1;
a	b
1	1
2	NULL
3	1
drop table t1, t2;
CREATE TABLE `t1` (
`id` mediumint(8) unsigned NOT NULL auto_increment,
`pseudo` varchar(35) NOT NULL default '',
`email` varchar(60) NOT NULL default '',
PRIMARY KEY  (`id`),
UNIQUE KEY `email` (`email`),
UNIQUE KEY `pseudo` (`pseudo`)
) ENGINE=MyISAM CHARSET=latin1 PACK_KEYS=1 ROW_FORMAT=DYNAMIC;
INSERT INTO t1 (id,pseudo,email) VALUES (1,'test','test'),(2,'test1','test1');
SELECT pseudo as a, pseudo as b FROM t1 GROUP BY (SELECT a) ORDER BY (SELECT id*1);
a	b
test	test
test1	test1
drop table if exists t1;
(SELECT 1 as a) UNION (SELECT 1) ORDER BY (SELECT a+0);
a
1
create table t1 (a int not null, b int, primary key (a));
create table t2 (a int not null, primary key (a));
create table t3 (a int not null, b int, primary key (a));
insert into t1 values (1,10), (2,20), (3,30),  (4,40);
insert into t2 values (2), (3), (4), (5);
insert into t3 values (10,3), (20,4), (30,5);
select * from t2 where t2.a in (select a from t1);
a
2
3
4
explain extended select * from t2 where t2.a in (select a from t1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer (flat, BNL join)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where (`test`.`t1`.`a` = `test`.`t2`.`a`)
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
a
2
4
explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
a
2
3
explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))
drop table t1, t2, t3;
create table t1 (a int, b int, index a (a,b));
create table t2 (a int, index a (a));
create table t3 (a int, b int, index a (a));
insert into t1 values (1,10), (2,20), (3,30), (4,40);
insert into t2 values (2), (3), (4), (5);
insert into t3 values (10,3), (20,4), (30,5);
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='semijoin_with_cache=off';
select * from t2 where t2.a in (select a from t1);
a
2
3
4
explain extended select * from t2 where t2.a in (select a from t1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using index; FirstMatch(t2)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) where (`test`.`t1`.`a` = `test`.`t2`.`a`)
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
a
2
4
explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using where; Using index; FirstMatch(t2)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
a
2
3
explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using where; Using index
1	PRIMARY	t3	ref	a	a	5	test.t1.b	1	100.00	Using index; FirstMatch(t2)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1` join `test`.`t3`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))
insert into t1 values (3,31);
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
a
2
3
4
select * from t2 where t2.a in (select a from t1 where t1.b <> 30 and t1.b <> 31);
a
2
4
explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using where; Using index; FirstMatch(t2)
Warnings:
Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
SET optimizer_switch=@save_optimizer_switch;
drop table t1, t2, t3;
create table t1 (a int, b int);
create table t2 (a int, b int);
create table t3 (a int, b int);
insert into t1 values (0,100),(1,2), (1,3), (2,2), (2,7), (2,-1), (3,10);
insert into t2 values (0,0), (1,1), (2,1), (3,1), (4,1);
insert into t3 values (3,3), (2,2), (1,1);
select a,(select count(distinct t1.b) as sum from t1,t2 where t1.a=t2.a and t2.b > 0 and t1.a <= t3.b group by t1.a order by sum limit 1) from t3;
a	(select count(distinct t1.b) as sum from t1,t2 where t1.a=t2.a and t2.b > 0 and t1.a <= t3.b group by t1.a order by sum limit 1)
3	1
2	2
1	2
drop table t1,t2,t3;
create table t1 (s1 int);
create table t2 (s1 int);
insert into t1 values (1);
insert into t2 values (1);
select * from t1 where exists (select s1 from t2 having max(t2.s1)=t1.s1);
s1
1
drop table t1,t2;
create table t1 (s1 int);
create table t2 (s1 int);
insert into t1 values (1);
insert into t2 values (1);
update t1 set  s1 = s1 + 1 where 1 = (select x.s1 as A from t2 WHERE t2.s1 > t1.s1 order by A);
ERROR 42S22: Unknown column 'x.s1' in 'field list'
DROP TABLE t1, t2;
CREATE TABLE t1 (s1 CHAR(5) COLLATE latin1_german1_ci,
s2 CHAR(5) COLLATE latin1_swedish_ci);
INSERT INTO t1 VALUES ('z','?');
select * from t1 where s1 > (select max(s2) from t1);
ERROR HY000: Illegal mix of collations (latin1_german1_ci,IMPLICIT) and (latin1_swedish_ci,IMPLICIT) for operation '>'
select * from t1 where s1 > any (select max(s2) from t1);
ERROR HY000: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (latin1_german1_ci,IMPLICIT) for operation '<'
drop table t1;
create table t1(toid int,rd int);
create table t2(userid int,pmnew int,pmtotal int);
insert into t2 values(1,0,0),(2,0,0);
insert into t1 values(1,0),(1,0),(1,0),(1,12),(1,15),(1,123),(1,12312),(1,12312),(1,123),(2,0),(2,0),(2,1),(2,2);
select userid,pmtotal,pmnew, (select count(rd) from t1 where toid=t2.userid) calc_total, (select count(rd) from t1 where rd=0 and toid=t2.userid) calc_new from t2 where userid in (select distinct toid from t1);
userid	pmtotal	pmnew	calc_total	calc_new
1	0	0	9	3
2	0	0	4	2
drop table t1, t2;
create table t1 (s1 char(5));
select (select 'a','b' from t1 union select 'a','b' from t1) from t1;
ERROR 21000: Operand should contain 1 column(s)
insert into t1 values ('tttt');
select * from t1 where ('a','b')=(select 'a','b' from t1 union select 'a','b' from t1);
s1
tttt
explain extended (select * from t1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1	100.00	
Warnings:
Note	1003	(select `test`.`t1`.`s1` AS `s1` from `test`.`t1`)
(select * from t1);
s1
tttt
drop table t1;
create table t1 (s1 char(5), index s1(s1));
create table t2 (s1 char(5), index s1(s1));
insert into t1 values ('a1'),('a2'),('a3');
insert into t2 values ('a1'),('a2');
select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
s1	s1 NOT IN (SELECT s1 FROM t2)
a1	0
a2	0
a3	1
select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
s1	s1 = ANY (SELECT s1 FROM t2)
a1	1
a2	1
a3	0
select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
s1	s1 <> ALL (SELECT s1 FROM t2)
a1	0
a2	0
a3	1
select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
s1	s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')
a1	0
a2	1
a3	1
explain extended select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
Warnings:
Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
explain extended select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
Warnings:
Note	1003	select `test`.`t1`.`s1` AS `s1`,<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
explain extended select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Full scan on NULL key
Warnings:
Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
explain extended select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	index	NULL	s1	6	NULL	3	100.00	Using index
2	DEPENDENT SUBQUERY	t2	index_subquery	s1	s1	6	func	2	100.00	Using index; Using where; Full scan on NULL key
Warnings:
Note	1003	select `test`.`t1`.`s1` AS `s1`,(not(<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where (`test`.`t2`.`s1` < 'a2') having trigcond(<is_not_null_test>(`test`.`t2`.`s1`)))))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
drop table t1,t2;
create table t2 (a int, b int not null);
create table t3 (a int);
insert into t3 values (6),(7),(3);
select * from t3 where a >= all (select b from t2);
a
6
7
3
explain extended select * from t3 where a >= all (select b from t2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(`test`.`t2`.`b`) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
select * from t3 where a >= some (select b from t2);
a
explain extended select * from t3 where a >= some (select b from t2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
select * from t3 where a >= all (select b from t2 group by 1);
a
6
7
3
explain extended select * from t3 where a >= all (select b from t2 group by 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,((select max(`test`.`t2`.`b`) from `test`.`t2`) > <cache>(`test`.`t3`.`a`))))
select * from t3 where a >= some (select b from t2 group by 1);
a
explain extended select * from t3 where a >= some (select b from t2 group by 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(`test`.`t3`.`a`,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= <cache>(`test`.`t3`.`a`))))
select * from t3 where NULL >= any (select b from t2);
a
explain extended select * from t3 where NULL >= any (select b from t2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= NULL)))
select * from t3 where NULL >= any (select b from t2 group by 1);
a
explain extended select * from t3 where NULL >= any (select b from t2 group by 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= NULL)))
select * from t3 where NULL >= some (select b from t2);
a
explain extended select * from t3 where NULL >= some (select b from t2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= NULL)))
select * from t3 where NULL >= some (select b from t2 group by 1);
a
explain extended select * from t3 where NULL >= some (select b from t2 group by 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	0	0.00	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>(<in_optimizer>(NULL,((select min(`test`.`t2`.`b`) from `test`.`t2`) <= NULL)))
insert into t2 values (2,2), (2,1), (3,3), (3,1);
select * from t3 where a > all (select max(b) from t2 group by a);
a
6
7
explain extended select * from t3 where a > all (select max(b) from t2 group by a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	4	100.00	Using temporary
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <not>(<in_optimizer>(`test`.`t3`.`a`,(<max>(select max(`test`.`t2`.`b`) from `test`.`t2` group by `test`.`t2`.`a`) >= <cache>(`test`.`t3`.`a`))))
drop table t2, t3;
CREATE TABLE `t1` ( `id` mediumint(9) NOT NULL auto_increment, `taskid` bigint(20) NOT NULL default '0', `dbid` int(11) NOT NULL default '0', `create_date` datetime NOT NULL default '0000-00-00 00:00:00', `last_update` datetime NOT NULL default '0000-00-00 00:00:00', PRIMARY KEY  (`id`)) ENGINE=MyISAM CHARSET=latin1 AUTO_INCREMENT=3 ;
INSERT INTO `t1` (`id`, `taskid`, `dbid`, `create_date`,`last_update`) VALUES (1, 1, 15, '2003-09-29 10:31:36', '2003-09-29 10:31:36'), (2, 1, 21, now(), now());
CREATE TABLE `t2` (`db_id` int(11) NOT NULL auto_increment,`name` varchar(200) NOT NULL default '',`primary_uid` smallint(6) NOT NULL default '0',`secondary_uid` smallint(6) NOT NULL default '0',PRIMARY KEY  (`db_id`),UNIQUE KEY `name_2` (`name`),FULLTEXT KEY `name` (`name`)) ENGINE=MyISAM CHARSET=latin1 AUTO_INCREMENT=2147483647;
INSERT INTO `t2` (`db_id`, `name`, `primary_uid`, `secondary_uid`) VALUES (18, 'Not Set 1', 0, 0),(19, 'Valid', 1, 2),(20, 'Valid 2', 1, 2),(21, 'Should Not Return', 1, 2),(26, 'Not Set 2', 0, 0),(-1, 'ALL DB\'S', 0, 0);
CREATE TABLE `t3` (`taskgenid` mediumint(9) NOT NULL auto_increment,`dbid` int(11) NOT NULL default '0',`taskid` int(11) NOT NULL default '0',`mon` tinyint(4) NOT NULL default '1',`tues` tinyint(4) NOT NULL default '1',`wed` tinyint(4) NOT NULL default '1',`thur` tinyint(4) NOT NULL default '1',`fri` tinyint(4) NOT NULL default '1',`sat` tinyint(4) NOT NULL default '0',`sun` tinyint(4) NOT NULL default '0',`how_often` smallint(6) NOT NULL default '1',`userid` smallint(6) NOT NULL default '0',`active` tinyint(4) NOT NULL default '1',PRIMARY KEY  (`taskgenid`)) ENGINE=MyISAM CHARSET=latin1 AUTO_INCREMENT=2 ;
INSERT INTO `t3` (`taskgenid`, `dbid`, `taskid`, `mon`, `tues`,`wed`, `thur`, `fri`, `sat`, `sun`, `how_often`, `userid`, `active`) VALUES (1,-1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1);
CREATE TABLE `t4` (`task_id` smallint(6) NOT NULL default '0',`description` varchar(200) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
INSERT INTO `t4` (`task_id`, `description`) VALUES (1, 'Daily Check List'),(2, 'Weekly Status');
select  dbid, name, (date_format(now() , '%Y-%m-%d') - INTERVAL how_often DAY) >= ifnull((SELECT date_format(max(create_date),'%Y-%m-%d') FROM t1 WHERE dbid = b.db_id AND taskid = a.taskgenid), '1950-01-01') from t3 a, t2 b, t4  WHERE dbid = - 1 AND primary_uid = '1' AND t4.task_id = taskid;
dbid	name	(date_format(now() , '%Y-%m-%d') - INTERVAL how_often DAY) >= ifnull((SELECT date_format(max(create_date),'%Y-%m-%d') FROM t1 WHERE dbid = b.db_id AND taskid = a.taskgenid), '1950-01-01')
-1	Valid	1
-1	Valid 2	1
-1	Should Not Return	0
SELECT dbid, name FROM t3 a, t2 b, t4 WHERE dbid = - 1 AND primary_uid = '1' AND ((date_format(now() , '%Y-%m-%d') - INTERVAL how_often DAY) >= ifnull((SELECT date_format(max(create_date),'%Y-%m-%d') FROM t1 WHERE dbid = b.db_id AND taskid = a.taskgenid), '1950-01-01')) AND t4.task_id = taskid;
dbid	name
-1	Valid
-1	Valid 2
drop table t1,t2,t3,t4;
CREATE TABLE t1 (id int(11) default NULL) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 VALUES (1),(5);
CREATE TABLE t2 (id int(11) default NULL) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t2 VALUES (2),(6);
select * from t1 where (1,2,6) in (select * from t2);
ERROR 21000: Operand should contain 3 column(s)
DROP TABLE t1,t2;
create table t1 (s1 int);
insert into t1 values (1);
insert into t1 values (2);
set sort_buffer_size = (select s1 from t1);
ERROR 21000: Subquery returns more than 1 row
do (select * from t1);
Warnings:
Error	1242	Subquery returns more than 1 row
drop table t1;
create table t1 (s1 char);
insert into t1 values ('e');
select * from t1 where 'f' > any (select s1 from t1);
s1
e
select * from t1 where 'f' > any (select s1 from t1 union select s1 from t1);
s1
e
explain extended select * from t1 where 'f' > any (select s1 from t1 union select s1 from t1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	1	100.00	
2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	100.00	
3	UNION	t1	ALL	NULL	NULL	NULL	NULL	1	100.00	
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	select `test`.`t1`.`s1` AS `s1` from `test`.`t1` where <nop>(<in_optimizer>('f',(<min>(select `test`.`t1`.`s1` from `test`.`t1` union select `test`.`t1`.`s1` from `test`.`t1`) < 'f')))
drop table t1;
CREATE TABLE t1 (number char(11) NOT NULL default '') ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t1 VALUES ('69294728265'),('18621828126'),('89356874041'),('95895001874');
CREATE TABLE t2 (code char(5) NOT NULL default '',UNIQUE KEY code (code)) ENGINE=MyISAM CHARSET=latin1;
INSERT INTO t2 VALUES ('1'),('1226'),('1245'),('1862'),('18623'),('1874'),('1967'),('6');
select c.number as phone,(select p.code from t2 p where c.number like concat(p.code, '%') order by length(p.code) desc limit 1) as code from t1 c;
phone	code
69294728265	6
18621828126	1862
89356874041	NULL
95895001874	NULL
drop table t1, t2;
create table t1 (s1 int);
create table t2 (s1 int);
select * from t1 where (select count(*) from t2 where t1.s2) = 1;
ERROR 42S22: Unknown column 't1.s2' in 'where clause'
select * from t1 where (select count(*) from t2 group by t1.s2) = 1;
ERROR 42S22: Unknown column 't1.s2' in 'group statement'
select count(*) from t2 group by t1.s2;
ERROR 42S22: Unknown column 't1.s2' in 'group statement'
drop table t1, t2;
CREATE TABLE t1(COLA FLOAT NOT NULL,COLB FLOAT NOT NULL,COLC VARCHAR(20) DEFAULT NULL,PRIMARY KEY (COLA, COLB));
CREATE TABLE t2(COLA FLOAT NOT NULL,COLB FLOAT NOT NULL,COLC CHAR(1) NOT NULL,PRIMARY KEY (COLA));
INSERT INTO t1 VALUES (1,1,'1A3240'), (1,2,'4W2365');
INSERT INTO t2 VALUES (100, 200, 'C');
SELECT DISTINCT COLC FROM t1 WHERE COLA = (SELECT COLA FROM t2 WHERE COLB = 200 AND COLC ='C' LIMIT 1);
COLC
DROP TABLE t1, t2;
CREATE TABLE t1 (a int(1));
INSERT INTO t1 VALUES (1),(1),(1),(1),(1),(2),(3),(4),(5);
SELECT DISTINCT (SELECT a) FROM t1 LIMIT 100;
(SELECT a)
1
2
3
4
5
DROP TABLE t1;
create table t1 (a int, b decimal(13, 3));
insert into t1 values (1, 0.123);
select a, (select max(b) from t1) into outfile "subselect.out.file.1" from t1;
delete from t1;
load data infile "subselect.out.file.1" into table t1;
select * from t1;
a	b
1	0.123
drop table t1;
CREATE TABLE `t1` (
`id` int(11) NOT NULL auto_increment,
`id_cns` tinyint(3) unsigned NOT NULL default '0',
`tipo` enum('','UNO','DUE') NOT NULL default '',
`anno_dep` smallint(4) unsigned zerofill NOT NULL default '0000',
`particolare` mediumint(8) unsigned NOT NULL default '0',
`generale` mediumint(8) unsigned NOT NULL default '0',
`bis` tinyint(3) unsigned NOT NULL default '0',
PRIMARY KEY  (`id`),
UNIQUE KEY `idx_cns_gen_anno` (`anno_dep`,`id_cns`,`generale`,`particolare`),
UNIQUE KEY `idx_cns_par_anno` (`id_cns`,`anno_dep`,`tipo`,`particolare`,`bis`)
);
INSERT INTO `t1` VALUES (1,16,'UNO',1987,2048,9681,0),(2,50,'UNO',1987,1536,13987,0),(3,16,'UNO',1987,2432,14594,0),(4,16,'UNO',1987,1792,13422,0),(5,16,'UNO',1987,1025,10240,0),(6,16,'UNO',1987,1026,7089,0);
CREATE TABLE `t2` (
`id` tinyint(3) unsigned NOT NULL auto_increment,
`max_anno_dep` smallint(6) unsigned NOT NULL default '0',
PRIMARY KEY  (`id`)
);
INSERT INTO `t2` VALUES (16,1987),(50,1990),(51,1990);
SELECT cns.id, cns.max_anno_dep, cns.max_anno_dep = (SELECT s.anno_dep FROM t1 AS s WHERE s.id_cns = cns.id ORDER BY s.anno_dep DESC LIMIT 1) AS PIPPO FROM t2 AS cns;
id	max_anno_dep	PIPPO
16	1987	1
50	1990	0
51	1990	NULL
DROP TABLE t1, t2;
create table t1 (a int);
insert into t1 values (1), (2), (3);
SET SQL_SELECT_LIMIT=1;
select sum(a) from (select * from t1) as a;
sum(a)
6
select 2 in (select * from t1);
2 in (select * from t1)
1
SET SQL_SELECT_LIMIT=default;
drop table t1;
CREATE TABLE t1 (a int, b int, INDEX (a));
INSERT INTO t1 VALUES (1, 1), (1, 2), (1, 3);
SELECT * FROM t1 WHERE a = (SELECT MAX(a) FROM t1 WHERE a = 1) ORDER BY b;
a	b
1	1
1	2
1	3
DROP TABLE t1;
create table t1(val varchar(10));
insert into t1 values ('aaa'), ('bbb'),('eee'),('mmm'),('ppp');
select count(*) from t1 as w1 where w1.val in (select w2.val from t1 as w2 where w2.val like 'm%') and w1.val in (select w3.val from t1 as w3 where w3.val like 'e%');
count(*)
0
drop table t1;
create table t1 (id int not null, text varchar(20) not null default '', primary key (id));
insert into t1 (id, text) values (1, 'text1'), (2, 'text2'), (3, 'text3'), (4, 'text4'), (5, 'text5'), (6, 'text6'), (7, 'text7'), (8, 'text8'), (9, 'text9'), (10, 'text10'), (11, 'text11'), (12, 'text12');
select * from t1 where id not in (select id from t1 where id < 8);
id	text
8	text8
9	text9
10	text10
11	text11
12	text12
select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null);
id	text
8	text8
9	text9
10	text10
11	text11
12	text12
explain extended select * from t1 where id not in (select id from t1 where id < 8);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
2	DEPENDENT SUBQUERY	t1	unique_subquery	PRIMARY	PRIMARY	4	func	1	100.00	Using index; Using where
Warnings:
Note	1003	select `test`.`t1`.`id` AS `id`,`test`.`t1`.`text` AS `text` from `test`.`t1` where (not(<expr_cache><`test`.`t1`.`id`>(<in_optimizer>(`test`.`t1`.`id`,<exists>(<primary_index_lookup>(<cache>(`test`.`t1`.`id`) in t1 on PRIMARY where ((`test`.`t1`.`id` < 8) and (<cache>(`test`.`t1`.`id`) = `test`.`t1`.`id`))))))))
explain extended select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	tt	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where
2	DEPENDENT SUBQUERY	t1	eq_ref	PRIMARY	PRIMARY	4	test.tt.id	1	100.00	Using where; Using index
Warnings:
Note	1276	Field or reference 'test.tt.id' of SELECT #2 was resolved in SELECT #1
Note	1003	select `test`.`tt`.`id` AS `id`,`test`.`tt`.`text` AS `text` from `test`.`t1` `tt` where (not(<expr_cache><`test`.`tt`.`id`>(exists(select `test`.`t1`.`id` from `test`.`t1` where ((`test`.`t1`.`id` < 8) and (`test`.`t1`.`id` = `test`.`tt`.`id`)) having (`test`.`t1`.`id` is not null)))))
insert into t1 (id, text) values (1000, 'text1000'), (1001, 'text1001');
create table t2 (id int not null, text varchar(20) not null default '', primary key (id));
insert into t2 (id, text) values (1, 'text1'), (2, 'text2'), (3, 'text3'), (4, 'text4'), (5, 'text5'), (6, 'text6'), (7, 'text7'), (8, 'text8'), (9, 'text9'), (10, 'text10'), (11, 'text1'), (12, 'text2'), (13, 'text3'), (14, 'text4'), (15, 'text5'), (16, 'text6'), (17, 'text7'), (18, 'text8'), (19, 'text9'), (20, 'text10'),(21, 'text1'), (22, 'text2'), (23, 'text3'), (24, 'text4'), (25, 'text5'), (26, 'text6'), (27, 'text7'), (28, 'text8'), (29, 'text9'), (30, 'text10'), (31, 'text1'), (32, 'text2'), (33, 'text3'), (34, 'text4'), (35, 'text5'), (36, 'text6'), (37, 'text7'), (38, 'text8'), (39, 'text9'), (40, 'text10'), (41, 'text1'), (42, 'text2'), (43, 'text3'), (44, 'text4'), (45, 'text5'), (46, 'text6'), (47, 'text7'), (48, 'text8'), (49, 'text9'), (50, 'text10');
select * from t1 a left join t2 b on (a.id=b.id or b.id is null) join t1 c on (if(isnull(b.id), 1000, b.id)=c.id);
id	text	id	text	id	text
1	text1	1	text1	1	text1
2	text2	2	text2	2	text2
3	text3	3	text3	3	text3
4	text4	4	text4	4	text4
5	text5	5	text5	5	text5
6	text6	6	text6	6	text6
7	text7	7	text7	7	text7
8	text8	8	text8	8	text8
9	text9	9	text9	9	text9
10	text10	10	text10	10	text10
11	text11	11	text1	11	text11
12	text12	12	text2	12	text12
1000	text1000	NULL	NULL	1000	text1000
1001	text1001	NULL	NULL	1000	text1000
explain extended select * from t1 a left join t2 b on (a.id=b.id or b.id is null) join t1 c on (if(isnull(b.id), 1000, b.id)=c.id);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	a	ALL	NULL	NULL	NULL	NULL	14	100.00	
1	SIMPLE	b	eq_ref	PRIMARY	PRIMARY	4	test.a.id	2	100.00	
1	SIMPLE	c	eq_ref	PRIMARY	PRIMARY	4	func	1	100.00	Using where
Warnings:
Note	1003	select `test`.`a`.`id` AS `id`,`test`.`a`.`text` AS `text`,`test`.`b`.`id` AS `id`,`test`.`b`.`text` AS `text`,`test`.`c`.`id` AS `id`,`test`.`c`.`text` AS `text` from `test`.`t1` `a` left join `test`.`t2` `b` on(((`test`.`b`.`id` = `test`.`a`.`id`) or isnull(`test`.`b`.`id`))) join `test`.`t1` `c` where (if(isnull(`test`.`b`.`id`),1000,`test`.`b`.`id`) = `test`.`c`.`id`)
drop table t1,t2;
set @@optimizer_switch=@save_optimizer_switch;
create table t1 (a int);
insert into t1 values (1);
explain select benchmark(1000, (select a from t1 where a=sha(rand())));
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
2	UNCACHEABLE SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	1	Using where
drop table t1;
create table t1(id int);
create table t2(id int);
create table t3(flag int);
select (select * from t3 where id not null) from t1, t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'null) from t1, t2' at line 1
drop table t1,t2,t3;
CREATE TABLE t1 (id INT);
CREATE TABLE t2 (id INT);
INSERT INTO t1 VALUES (1), (2);
INSERT INTO t2 VALUES (1);
SELECT t1.id, ( SELECT COUNT(t.id) FROM t2 AS t WHERE t.id = t1.id ) AS c FROM t1 LEFT JOIN t2 USING (id);
id	c
1	1
2	0
SELECT id, ( SELECT COUNT(t.id) FROM t2 AS t WHERE t.id = t1.id ) AS c FROM t1 LEFT JOIN t2 USING (id);
id	c
1	1
2	0
SELECT t1.id, ( SELECT COUNT(t.id) FROM t2 AS t WHERE t.id = t1.id ) AS c FROM t1 LEFT JOIN t2 USING (id) ORDER BY t1.id;
id	c
1	1
2	0
SELECT id, ( SELECT COUNT(t.id) FROM t2 AS t WHERE t.id = t1.id ) AS c FROM t1 LEFT JOIN t2 USING (id) ORDER BY id;
id	c
1	1
2	0
DROP TABLE t1,t2;
CREATE TABLE t1 ( a int, b int );
INSERT INTO t1 VALUES (1,1),(2,2),(3,3);
SELECT a FROM t1 WHERE a > ANY ( SELECT a FROM t1 WHERE b = 2 );
a
3
SELECT a FROM t1 WHERE a < ANY ( SELECT a FROM t1 WHERE b = 2 );
a
1
SELECT a FROM t1 WHERE a = ANY ( SELECT a FROM t1 WHERE b = 2 );
a
2
SELECT a FROM t1 WHERE a >= ANY ( SELECT a FROM t1 WHERE b = 2 );
a
2
3
SELECT a FROM t1 WHERE a <= ANY ( SELECT a FROM t1 WHERE b = 2 );
a
1
2
SELECT a FROM t1 WHERE a <> ANY ( SELECT a FROM t1 WHERE b = 2 );
a
1
3
SELECT a FROM t1 WHERE a > ALL ( SELECT a FROM t1 WHERE b = 2 );
a
3
SELECT a FROM t1 WHERE a < ALL ( SELECT a FROM t1 WHERE b = 2 );
a
1
SELECT a FROM t1 WHERE a = ALL ( SELECT a FROM t1 WHERE b = 2 );
a
2
SELECT a FROM t1 WHERE a >= ALL ( SELECT a FROM t1 WHERE b = 2 );
a
2
3
SELECT a FROM t1 WHERE a <= ALL ( SELECT a FROM t1 WHERE b = 2 );
a
1
2
SELECT a FROM t1 WHERE a <> ALL ( SELECT a FROM t1 WHERE b = 2 );
a
1
3
ALTER TABLE t1 ADD INDEX (a);
SELECT a FROM t1 WHERE a > ANY ( SELECT a FROM t1 WHERE b = 2 );
a
3
SELECT a FROM t1 WHERE a < ANY ( SELECT a FROM t1 WHERE b = 2 );
a
1
SELECT a FROM t1 WHERE a = ANY ( SELECT a FROM t1 WHERE b = 2 );
a
2
SELECT a FROM t1 WHERE a >= ANY ( SELECT a FROM t1 WHERE b = 2 );
a
2
3
SELECT a FROM t1 WHERE a <= ANY ( SELECT a FROM t1 WHERE b = 2 );
a
1
2
SELECT a FROM t1 WHERE a <> ANY ( SELECT a FROM t1 WHERE b = 2 );
a
1
3
SELECT a FROM t1 WHERE a > ALL ( SELECT a FROM t1 WHERE b = 2 );
a
3
SELECT a FROM t1 WHERE a < ALL ( SELECT a FROM t1 WHERE b = 2 );
a
1
SELECT a FROM t1 WHERE a = ALL ( SELECT a FROM t1 WHERE b = 2 );
a
2
SELECT a FROM t1 WHERE a >= ALL ( SELECT a FROM t1 WHERE b = 2 );
a
2
3
SELECT a FROM t1 WHERE a <= ALL ( SELECT a FROM t1 WHERE b = 2 );
a
1
2
SELECT a FROM t1 WHERE a <> ALL ( SELECT a FROM t1 WHERE b = 2 );
a
1
3
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 HAVING a = 2);
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 HAVING a = 2);
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 HAVING a = 2);
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 HAVING a = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 HAVING a = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 HAVING a = 2);
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 HAVING a = 2);
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 HAVING a = 2);
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 HAVING a = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 HAVING a = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 WHERE b = 2 UNION SELECT a FROM t1 WHERE b = 2);
a
1
3
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 HAVING a = 2 UNION SELECT a FROM t1 HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE (1,2) > ANY (SELECT a FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE a > ANY (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) > ANY (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) > ALL (SELECT a FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE a > ALL (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) > ALL (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) = ALL (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) <> ANY (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) = ANY (SELECT a FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 2 column(s)
SELECT a FROM t1 WHERE a = ANY (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) = ANY (SELECT a,2 FROM t1 WHERE b = 2);
a
SELECT a FROM t1 WHERE (1,2) <> ALL (SELECT a FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 2 column(s)
SELECT a FROM t1 WHERE a <> ALL (SELECT a,2 FROM t1 WHERE b = 2);
ERROR 21000: Operand should contain 1 column(s)
SELECT a FROM t1 WHERE (1,2) <> ALL (SELECT a,2 FROM t1 WHERE b = 2);
a
1
2
3
SELECT a FROM t1 WHERE (a,1) = ANY (SELECT a,1 FROM t1 WHERE b = 2);
a
2
SELECT a FROM t1 WHERE (a,1) <> ALL (SELECT a,1 FROM t1 WHERE b = 2);
a
1
3
SELECT a FROM t1 WHERE (a,1) = ANY (SELECT a,1 FROM t1 HAVING a = 2);
a
2
SELECT a FROM t1 WHERE (a,1) <> ALL (SELECT a,1 FROM t1 HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE (a,1) = ANY (SELECT a,1 FROM t1 WHERE b = 2 UNION SELECT a,1 FROM t1 WHERE b = 2);
a
2
SELECT a FROM t1 WHERE (a,1) <> ALL (SELECT a,1 FROM t1 WHERE b = 2 UNION SELECT a,1 FROM t1 WHERE b = 2);
a
1
3
SELECT a FROM t1 WHERE (a,1) = ANY (SELECT a,1 FROM t1 HAVING a = 2 UNION SELECT a,1 FROM t1 HAVING a = 2);
a
2
SELECT a FROM t1 WHERE (a,1) <> ALL (SELECT a,1 FROM t1 HAVING a = 2 UNION SELECT a,1 FROM t1 HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 WHERE b = 2 group by a);
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 WHERE b = 2 group by a);
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 WHERE b = 2 group by a);
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 WHERE b = 2 group by a);
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 WHERE b = 2 group by a);
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 WHERE b = 2 group by a);
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 WHERE b = 2 group by a);
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 WHERE b = 2 group by a);
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 WHERE b = 2 group by a);
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 WHERE b = 2 group by a);
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 WHERE b = 2 group by a);
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 WHERE b = 2 group by a);
a
1
3
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 group by a HAVING a = 2);
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 group by a HAVING a = 2);
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 group by a HAVING a = 2);
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 group by a HAVING a = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 group by a HAVING a = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 group by a HAVING a = 2);
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 group by a HAVING a = 2);
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 group by a HAVING a = 2);
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 group by a HAVING a = 2);
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 group by a HAVING a = 2);
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 group by a HAVING a = 2);
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 group by a HAVING a = 2);
a
1
3
SELECT concat(EXISTS(SELECT a FROM t1 WHERE b = 2 and a.a > t1.a), '-') from t1 a;
concat(EXISTS(SELECT a FROM t1 WHERE b = 2 and a.a > t1.a), '-')
0-
0-
1-
SELECT concat(EXISTS(SELECT a FROM t1 WHERE b = 2 and a.a < t1.a), '-') from t1 a;
concat(EXISTS(SELECT a FROM t1 WHERE b = 2 and a.a < t1.a), '-')
1-
0-
0-
SELECT concat(EXISTS(SELECT a FROM t1 WHERE b = 2 and a.a = t1.a), '-') from t1 a;
concat(EXISTS(SELECT a FROM t1 WHERE b = 2 and a.a = t1.a), '-')
0-
1-
0-
DROP TABLE t1;
CREATE TABLE t1 ( a double, b double );
INSERT INTO t1 VALUES (1,1),(2,2),(3,3);
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 WHERE b = 2e0);
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 WHERE b = 2e0);
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 WHERE b = 2e0);
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 WHERE b = 2e0);
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 WHERE b = 2e0);
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 WHERE b = 2e0);
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 WHERE b = 2e0);
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 WHERE b = 2e0);
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 WHERE b = 2e0);
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 WHERE b = 2e0);
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 WHERE b = 2e0);
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 WHERE b = 2e0);
a
1
3
DROP TABLE t1;
CREATE TABLE t1 ( a char(1), b char(1));
INSERT INTO t1 VALUES ('1','1'),('2','2'),('3','3');
SELECT a FROM t1 WHERE a > ANY (SELECT a FROM t1 WHERE b = '2');
a
3
SELECT a FROM t1 WHERE a < ANY (SELECT a FROM t1 WHERE b = '2');
a
1
SELECT a FROM t1 WHERE a = ANY (SELECT a FROM t1 WHERE b = '2');
a
2
SELECT a FROM t1 WHERE a >= ANY (SELECT a FROM t1 WHERE b = '2');
a
2
3
SELECT a FROM t1 WHERE a <= ANY (SELECT a FROM t1 WHERE b = '2');
a
1
2
SELECT a FROM t1 WHERE a <> ANY (SELECT a FROM t1 WHERE b = '2');
a
1
3
SELECT a FROM t1 WHERE a > ALL (SELECT a FROM t1 WHERE b = '2');
a
3
SELECT a FROM t1 WHERE a < ALL (SELECT a FROM t1 WHERE b = '2');
a
1
SELECT a FROM t1 WHERE a = ALL (SELECT a FROM t1 WHERE b = '2');
a
2
SELECT a FROM t1 WHERE a >= ALL (SELECT a FROM t1 WHERE b = '2');
a
2
3
SELECT a FROM t1 WHERE a <= ALL (SELECT a FROM t1 WHERE b = '2');
a
1
2
SELECT a FROM t1 WHERE a <> ALL (SELECT a FROM t1 WHERE b = '2');
a
1
3
DROP TABLE t1;
create table t1 (a int, b int);
insert into t1 values (1,2),(3,4);
select * from t1 up where exists (select * from t1 where t1.a=up.a);
a	b
1	2
3	4
explain extended select * from t1 up where exists (select * from t1 where t1.a=up.a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	up	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
Warnings:
Note	1276	Field or reference 'test.up.a' of SELECT #2 was resolved in SELECT #1
Note	1003	select `test`.`up`.`a` AS `a`,`test`.`up`.`b` AS `b` from `test`.`t1` `up` where <expr_cache><`test`.`up`.`a`>(exists(select 1 from `test`.`t1` where (`test`.`t1`.`a` = `test`.`up`.`a`)))
drop table t1;
CREATE TABLE t1 (t1_a int);
INSERT INTO t1 VALUES (1);
CREATE TABLE t2 (t2_a int, t2_b int, PRIMARY KEY (t2_a, t2_b));
INSERT INTO t2 VALUES (1, 1), (1, 2);
SELECT * FROM t1, t2 table2 WHERE t1_a = 1 AND table2.t2_a = 1
HAVING table2.t2_b = (SELECT MAX(t2_b) FROM t2 WHERE t2_a = table2.t2_a);
t1_a	t2_a	t2_b
1	1	2
DROP TABLE t1, t2;
CREATE TABLE t1 (id int(11) default NULL,name varchar(10) default NULL);
INSERT INTO t1 VALUES (1,'Tim'),(2,'Rebecca'),(3,NULL);
CREATE TABLE t2 (id int(11) default NULL, pet varchar(10) default NULL);
INSERT INTO t2 VALUES (1,'Fido'),(2,'Spot'),(3,'Felix');
SELECT a.*, b.* FROM (SELECT * FROM t1) AS a JOIN t2 as b on a.id=b.id;
id	name	id	pet
1	Tim	1	Fido
2	Rebecca	2	Spot
3	NULL	3	Felix
drop table t1,t2;
CREATE TABLE t1 ( a int, b int );
CREATE TABLE t2 ( c int, d int );
INSERT INTO t1 VALUES (1,2), (2,3), (3,4);
SELECT a AS abc, b FROM t1 outr WHERE b = 
(SELECT MIN(b) FROM t1 WHERE a=outr.a);
abc	b
1	2
2	3
3	4
INSERT INTO t2 SELECT a AS abc, b FROM t1 outr WHERE b = 
(SELECT MIN(b) FROM t1 WHERE a=outr.a);
select * from t2;
c	d
1	2
2	3
3	4
CREATE TABLE t3 SELECT a AS abc, b FROM t1 outr WHERE b = 
(SELECT MIN(b) FROM t1 WHERE a=outr.a);
select * from t3;
abc	b
1	2
2	3
3	4
prepare stmt1 from "INSERT INTO t2 SELECT a AS abc, b FROM t1 outr WHERE b = (SELECT MIN(b) FROM t1 WHERE a=outr.a);";
execute stmt1;
deallocate prepare stmt1;
select * from t2;
c	d
1	2
2	3
3	4
1	2
2	3
3	4
drop table t3;
prepare stmt1 from "CREATE TABLE t3 SELECT a AS abc, b FROM t1 outr WHERE b = (SELECT MIN(b) FROM t1 WHERE a=outr.a);";
execute stmt1;
select * from t3;
abc	b
1	2
2	3
3	4
deallocate prepare stmt1;
DROP TABLE t1, t2, t3;
CREATE TABLE `t1` ( `a` int(11) default NULL) ENGINE=MyISAM DEFAULT CHARSET=latin1;
insert into t1 values (1);
CREATE TABLE `t2` ( `b` int(11) default NULL, `a` int(11) default NULL) ENGINE=MyISAM DEFAULT CHARSET=latin1;
insert into t2 values (1,2);
select t000.a, count(*) `C` FROM t1 t000 GROUP BY t000.a HAVING count(*) > ALL (SELECT count(*) FROM t2 t001 WHERE t001.a=1);
a	C
1	1
drop table t1,t2;
create table t1 (a int not null auto_increment primary key, b varchar(40), fulltext(b)) engine=myisam;
insert into t1 (b) values ('ball'),('ball games'), ('games'), ('foo'), ('foobar'), ('Serg'), ('Sergei'),('Georg'), ('Patrik'),('Hakan');
create table t2 (a int);
insert into t2 values (1),(3),(2),(7);
select a,b from t1 where match(b) against ('Ball') > 0;
a	b
1	ball
2	ball games
select a from t2 where a in (select a from t1 where match(b) against ('Ball') > 0);
a
1
2
drop table t1,t2;
CREATE TABLE t1(`IZAVORGANG_ID` VARCHAR(11) CHARACTER SET latin1 COLLATE latin1_bin,`KUERZEL` VARCHAR(10) CHARACTER SET latin1 COLLATE latin1_bin,`IZAANALYSEART_ID` VARCHAR(11) CHARACTER SET latin1 COLLATE latin1_bin,`IZAPMKZ_ID` VARCHAR(11) CHARACTER SET latin1 COLLATE latin1_bin);
CREATE INDEX AK01IZAVORGANG ON t1(izaAnalyseart_id,Kuerzel);
INSERT INTO t1(`IZAVORGANG_ID`,`KUERZEL`,`IZAANALYSEART_ID`,`IZAPMKZ_ID`)VALUES('D0000000001','601','D0000000001','I0000000001');
INSERT INTO t1(`IZAVORGANG_ID`,`KUERZEL`,`IZAANALYSEART_ID`,`IZAPMKZ_ID`)VALUES('D0000000002','602','D0000000001','I0000000001');
INSERT INTO t1(`IZAVORGANG_ID`,`KUERZEL`,`IZAANALYSEART_ID`,`IZAPMKZ_ID`)VALUES('D0000000003','603','D0000000001','I0000000001');
INSERT INTO t1(`IZAVORGANG_ID`,`KUERZEL`,`IZAANALYSEART_ID`,`IZAPMKZ_ID`)VALUES('D0000000004','101','D0000000001','I0000000001');
SELECT `IZAVORGANG_ID` FROM t1 WHERE `KUERZEL` IN(SELECT MIN(`KUERZEL`)`Feld1` FROM t1 WHERE `KUERZEL` LIKE'601%'And`IZAANALYSEART_ID`='D0000000001');
IZAVORGANG_ID
D0000000001
drop table t1;
CREATE TABLE `t1` ( `aid` int(11) NOT NULL default '0', `bid` int(11) NOT NULL default '0', PRIMARY KEY  (`aid`,`bid`));
CREATE TABLE `t2` ( `aid` int(11) NOT NULL default '0', `bid` int(11) NOT NULL default '0', PRIMARY KEY  (`aid`,`bid`));
insert into t1 values (1,1),(1,2),(2,1),(2,2);
insert into t2 values (1,2),(2,2);
select * from t1 where t1.aid not in (select aid from t2 where bid=t1.bid);
aid	bid
1	1
2	1
alter table t2 drop primary key;
alter table t2 add key KEY1 (aid, bid);
select * from t1 where t1.aid not in (select aid from t2 where bid=t1.bid);
aid	bid
1	1
2	1
alter table t2 drop key KEY1;
alter table t2 add primary key (bid, aid);
select * from t1 where t1.aid not in (select aid from t2 where bid=t1.bid);
aid	bid
1	1
2	1
drop table t1,t2;
CREATE TABLE t1 (howmanyvalues bigint, avalue int);
INSERT INTO t1 VALUES (1, 1),(2, 1),(2, 2),(3, 1),(3, 2),(3, 3),(4, 1),(4, 2),(4, 3),(4, 4);
SELECT howmanyvalues, count(*) from t1 group by howmanyvalues;
howmanyvalues	count(*)
1	1
2	2
3	3
4	4
SELECT a.howmanyvalues, (SELECT count(*) from t1 b where b.howmanyvalues = a.howmanyvalues) as mycount from t1 a group by a.howmanyvalues;
howmanyvalues	mycount
1	1
2	2
3	3
4	4
CREATE INDEX t1_howmanyvalues_idx ON t1 (howmanyvalues);
SELECT a.howmanyvalues, (SELECT count(*) from t1 b where b.howmanyvalues+1 = a.howmanyvalues+1) as mycount from t1 a group by a.howmanyvalues;
howmanyvalues	mycount
1	1
2	2
3	3
4	4
SELECT a.howmanyvalues, (SELECT count(*) from t1 b where b.howmanyvalues = a.howmanyvalues) as mycount from t1 a group by a.howmanyvalues;
howmanyvalues	mycount
1	1
2	2
3	3
4	4
SELECT a.howmanyvalues, (SELECT count(*) from t1 b where b.howmanyvalues = a.avalue) as mycount from t1 a group by a.howmanyvalues;
howmanyvalues	mycount
1	1
2	1
3	1
4	1
drop table t1;
create table t1 (x int);
select  (select b.x from t1 as b where b.x=a.x) from t1 as a where a.x=2 group by a.x;
(select b.x from t1 as b where b.x=a.x)
drop table t1;
CREATE TABLE `t1` ( `master` int(10) unsigned NOT NULL default '0', `map` smallint(6) unsigned NOT NULL default '0', `slave` int(10) unsigned NOT NULL default '0', `access` int(10) unsigned NOT NULL default '0', UNIQUE KEY `access_u` (`master`,`map`,`slave`));
INSERT INTO `t1` VALUES (1,0,0,700),(1,1,1,400),(1,5,5,400),(1,12,12,400),(1,12,32,400),(4,12,32,400);
CREATE TABLE `t2` ( `id` int(10) unsigned NOT NULL default '0', `pid` int(10) unsigned NOT NULL default '0', `map` smallint(6) unsigned NOT NULL default '0', `level` tinyint(4) unsigned NOT NULL default '0', `title` varchar(255) default NULL, PRIMARY KEY  (`id`,`pid`,`map`), KEY `level` (`level`), KEY `id` (`id`,`map`)) ;
INSERT INTO `t2` VALUES (6,5,12,7,'a'),(12,0,0,7,'a'),(12,1,0,7,'a'),(12,5,5,7,'a'),(12,5,12,7,'a');
SELECT b.sc FROM (SELECT (SELECT a.access FROM t1 a WHERE a.map = op.map AND a.slave = op.pid AND a.master = 1) ac FROM t2 op WHERE op.id = 12 AND op.map = 0) b;
ERROR 42S22: Unknown column 'b.sc' in 'field list'
SELECT b.ac FROM (SELECT (SELECT a.access FROM t1 a WHERE a.map = op.map AND a.slave = op.pid AND a.master = 1) ac FROM t2 op WHERE op.id = 12 AND op.map = 0) b;
ac
700
NULL
drop tables t1,t2;
create table t1 (a int not null, b int not null, c int, primary key (a,b));
insert into t1 values (1,1,1), (2,2,2), (3,3,3);
set @b:= 0;
explain select sum(a) from t1 where b > @b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	PRIMARY	8	NULL	3	Using where; Using index
set @a:= (select sum(a) from t1 where b > @b);
explain select a from t1 where c=2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
do @a:= (select sum(a) from t1 where b > @b);
explain select a from t1 where c=2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
drop table t1;
set @got_val= (SELECT 1 FROM (SELECT 'A' as my_col) as T1 ) ;
create table t1 (a int, b int);
create table t2 (a int, b int);
insert into t1 values (1,1),(1,2),(1,3),(2,4),(2,5);
insert into t2 values (1,3),(2,1);
select distinct a,b, (select max(b) from t2 where t1.b=t2.a) from t1 order by t1.b;
a	b	(select max(b) from t2 where t1.b=t2.a)
1	1	3
1	2	1
1	3	NULL
2	4	NULL
2	5	NULL
drop table t1, t2;
create table t1 (id int);
create table t2 (id int, body text, fulltext (body)) engine=myisam;
insert into t1 values(1),(2),(3);
insert into t2 values (1,'test'), (2,'mysql'), (3,'test'), (4,'test');
select count(distinct id) from t1 where id in (select id from t2 where match(body) against ('mysql' in boolean mode));
count(distinct id)
1
drop table t2,t1;
create table t1 (s1 int,s2 int);
insert into t1 values (20,15);
select * from t1 where  (('a',null) <=> (select 'a',s2 from t1 where s1 = 0));
s1	s2
drop table t1;
create table t1 (s1 int);
insert into t1 values (1),(null);
select * from t1 where s1 < all (select s1 from t1);
s1
select s1, s1 < all (select s1 from t1) from t1;
s1	s1 < all (select s1 from t1)
1	0
NULL	NULL
drop table t1;
CREATE TABLE t1 (
Code char(3) NOT NULL default '',
Name char(52) NOT NULL default '',
Continent enum('Asia','Europe','North America','Africa','Oceania','Antarctica','South America') NOT NULL default 'Asia',
Region char(26) NOT NULL default '',
SurfaceArea float(10,2) NOT NULL default '0.00',
IndepYear smallint(6) default NULL,
Population int(11) NOT NULL default '0',
LifeExpectancy float(3,1) default NULL,
GNP float(10,2) default NULL,
GNPOld float(10,2) default NULL,
LocalName char(45) NOT NULL default '',
GovernmentForm char(45) NOT NULL default '',
HeadOfState char(60) default NULL,
Capital int(11) default NULL,
Code2 char(2) NOT NULL default ''
) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('XXX','Xxxxx','Oceania','Xxxxxx',26.00,0,0,0,0,0,'Xxxxx','Xxxxx','Xxxxx',NULL,'XX');
INSERT INTO t1 VALUES ('ASM','American Samoa','Oceania','Polynesia',199.00,0,68000,75.1,334.00,NULL,'Amerika Samoa','US Territory','George W. Bush',54,'AS');
INSERT INTO t1 VALUES ('ATF','French Southern territories','Antarctica','Antarctica',7780.00,0,0,NULL,0.00,NULL,'Terres australes françaises','Nonmetropolitan Territory of France','Jacques Chirac',NULL,'TF');
INSERT INTO t1 VALUES ('UMI','United States Minor Outlying Islands','Oceania','Micronesia/Caribbean',16.00,0,0,NULL,0.00,NULL,'United States Minor Outlying Islands','Dependent Territory of the US','George W. Bush',NULL,'UM');
/*!40000 ALTER TABLE t1 ENABLE KEYS */;
SELECT DISTINCT Continent AS c FROM t1 outr WHERE 
Code <> SOME ( SELECT Code FROM t1 WHERE Continent = outr.Continent AND 
Population < 200);
c
Oceania
drop table t1;
create table t1 (a1 int);
create table t2 (b1 int);
select * from t1 where a2 > any(select b1 from t2);
ERROR 42S22: Unknown column 'a2' in 'IN/ALL/ANY subquery'
select * from t1 where a1 > any(select b1 from t2);
a1
drop table t1,t2;
create table t1 (a integer, b integer);
select (select * from t1) = (select 1,2);
(select * from t1) = (select 1,2)
NULL
select (select 1,2) = (select * from t1);
(select 1,2) = (select * from t1)
NULL
select  row(1,2) = ANY (select * from t1);
row(1,2) = ANY (select * from t1)
0
select  row(1,2) != ALL (select * from t1);
row(1,2) != ALL (select * from t1)
1
drop table t1;
create table t1 (a integer, b integer);
select row(1,(2,2)) in (select * from t1 );
ERROR 21000: Operand should contain 2 column(s)
select row(1,(2,2)) = (select * from t1 );
ERROR 21000: Operand should contain 2 column(s)
select (select * from t1) = row(1,(2,2));
ERROR 21000: Operand should contain 1 column(s)
drop table t1;
create  table t1 (a integer);
insert into t1 values (1);
select 1 = ALL (select 1 from t1 where 1 = xx ), 1 as xx ;
ERROR 42S22: Reference 'xx' not supported (forward reference in item list)
select 1 = ALL (select 1 from t1 where 1 = xx ), 1 as xx;
ERROR 42S22: Reference 'xx' not supported (forward reference in item list)
select 1 as xx, 1 = ALL (  select 1 from t1 where 1 = xx );
xx	1 = ALL (  select 1 from t1 where 1 = xx )
1	1
select 1 = ALL (select 1 from t1 where 1 = xx ), 1 as xx;
ERROR 42S22: Reference 'xx' not supported (forward reference in item list)
select 1 = ALL (select 1 from t1 where 1 = xx ), 1 as xx from DUAL;
ERROR 42S22: Reference 'xx' not supported (forward reference in item list)
drop table t1;
CREATE TABLE t1 (
categoryId int(11) NOT NULL,
courseId int(11) NOT NULL,
startDate datetime NOT NULL,
endDate datetime NOT NULL,
createDate datetime NOT NULL,
modifyDate timestamp NOT NULL,
attributes text NOT NULL
);
INSERT INTO t1 VALUES (1,41,'2004-02-09','2010-01-01','2004-02-09','2004-02-09',''),
(1,86,'2004-08-16','2004-08-16','2004-08-16','2004-08-16',''),
(1,87,'2004-08-16','2004-08-16','2004-08-16','2004-08-16',''),
(2,52,'2004-03-15','2004-10-01','2004-03-15','2004-09-17',''),
(2,53,'2004-03-16','2004-10-01','2004-03-16','2004-09-17',''),
(2,88,'2004-08-16','2004-08-16','2004-08-16','2004-08-16',''),
(2,89,'2004-08-16','2004-08-16','2004-08-16','2004-08-16',''),
(3,51,'2004-02-09','2010-01-01','2004-02-09','2004-02-09',''),
(5,12,'2004-02-18','2010-01-01','2004-02-18','2004-02-18','');
CREATE TABLE t2 (
userId int(11) NOT NULL,
courseId int(11) NOT NULL,
date datetime NOT NULL
);
INSERT INTO t2 VALUES (5141,71,'2003-11-18'),
(5141,72,'2003-11-25'),(5141,41,'2004-08-06'),
(5141,52,'2004-08-06'),(5141,53,'2004-08-06'),
(5141,12,'2004-08-06'),(5141,86,'2004-10-21'),
(5141,87,'2004-10-21'),(5141,88,'2004-10-21'),
(5141,89,'2004-10-22'),(5141,51,'2004-10-26');
CREATE TABLE t3 (
groupId int(11) NOT NULL,
parentId int(11) NOT NULL,
startDate datetime NOT NULL,
endDate datetime NOT NULL,
createDate datetime NOT NULL,
modifyDate timestamp NOT NULL,
ordering int(11)
);
INSERT INTO t3 VALUES (12,9,'1000-01-01','3999-12-31','2004-01-29','2004-01-29',NULL);
CREATE TABLE t4 (
id int(11) NOT NULL,
groupTypeId int(11) NOT NULL,
groupKey varchar(50) NOT NULL,
name text,
ordering int(11),
description text,
createDate datetime NOT NULL,
modifyDate timestamp NOT NULL
);
INSERT INTO t4 VALUES (9,5,'stationer','stationer',0,'Stationer','2004-01-29','2004-01-29'),
(12,5,'group2','group2',0,'group2','2004-01-29','2004-01-29');
CREATE TABLE t5 (
userId int(11) NOT NULL,
groupId int(11) NOT NULL,
createDate datetime NOT NULL,
modifyDate timestamp NOT NULL
);
INSERT INTO t5 VALUES (5141,12,'2004-08-06','2004-08-06');
select
count(distinct t2.userid) pass,
groupstuff.*,
count(t2.courseid) crse,
t1.categoryid, 
t2.courseid,
date_format(date, '%b%y') as colhead
from t2   
join t1 on t2.courseid=t1.courseid  
join
(
select 
t5.userid,  
parentid,  
parentgroup,  
childid,  
groupname,  
grouptypeid  
from t5 
join 
(
select t4.id as parentid,  
t4.name as parentgroup,  
t4.id as childid,  
t4.name as groupname,  
t4.grouptypeid  
from   t4  
) as gin on t5.groupid=gin.childid 
) as groupstuff on t2.userid = groupstuff.userid 
group by 
groupstuff.groupname, colhead , t2.courseid;
pass	userid	parentid	parentgroup	childid	groupname	grouptypeid	crse	categoryid	courseid	colhead
1	5141	12	group2	12	group2	5	1	5	12	Aug04
1	5141	12	group2	12	group2	5	1	1	41	Aug04
1	5141	12	group2	12	group2	5	1	2	52	Aug04
1	5141	12	group2	12	group2	5	1	2	53	Aug04
1	5141	12	group2	12	group2	5	1	3	51	Oct04
1	5141	12	group2	12	group2	5	1	1	86	Oct04
1	5141	12	group2	12	group2	5	1	1	87	Oct04
1	5141	12	group2	12	group2	5	1	2	88	Oct04
1	5141	12	group2	12	group2	5	1	2	89	Oct04
drop table t1, t2, t3, t4, t5;
create table t1 (a int);
insert into t1 values (1), (2), (3);
SELECT 1 FROM t1 WHERE (SELECT 1) in (SELECT 1);
1
1
1
1
drop table t1;
create table t1 (a int);
create table t2 (a int);
insert into t1 values (1),(2);
insert into t2 values (0),(1),(2),(3);
select a from t2 where a in (select a from t1);
a
1
2
select a from t2 having a in (select a from t1);
a
1
2
prepare stmt1 from "select a from t2 where a in (select a from t1)";
execute stmt1;
a
1
2
execute stmt1;
a
1
2
deallocate prepare stmt1;
prepare stmt1 from "select a from t2 having a in (select a from t1)";
execute stmt1;
a
1
2
execute stmt1;
a
1
2
deallocate prepare stmt1;
drop table t1, t2;
create table t1 (a int, b int);
insert into t1 values (1,2);
select 1 = (select * from t1);
ERROR 21000: Operand should contain 1 column(s)
select (select * from t1) = 1;
ERROR 21000: Operand should contain 2 column(s)
select (1,2) = (select a from t1);
ERROR 21000: Operand should contain 2 column(s)
select (select a from t1) = (1,2);
ERROR 21000: Operand should contain 1 column(s)
select (1,2,3) = (select * from t1);
ERROR 21000: Operand should contain 3 column(s)
select (select * from t1) = (1,2,3);
ERROR 21000: Operand should contain 2 column(s)
drop table t1;
CREATE TABLE `t1` (
`itemid` bigint(20) unsigned NOT NULL auto_increment,
`sessionid` bigint(20) unsigned default NULL,
`time` int(10) unsigned NOT NULL default '0',
`type` set('A','D','E','F','G','I','L','N','U') collate latin1_general_ci NOT
NULL default '',
`data` text collate latin1_general_ci NOT NULL,
PRIMARY KEY  (`itemid`)
) DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;
INSERT INTO `t1` VALUES (1, 1, 1, 'D', '');
CREATE TABLE `t2` (
`sessionid` bigint(20) unsigned NOT NULL auto_increment,
`pid` int(10) unsigned NOT NULL default '0',
`date` int(10) unsigned NOT NULL default '0',
`ip` varchar(15) collate latin1_general_ci NOT NULL default '',
PRIMARY KEY  (`sessionid`)
) DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;
INSERT INTO `t2` VALUES (1, 1, 1, '10.10.10.1');
SELECT s.ip, count( e.itemid ) FROM `t1` e JOIN t2 s ON s.sessionid = e.sessionid WHERE e.sessionid = ( SELECT sessionid FROM t2 ORDER BY sessionid DESC LIMIT 1 ) GROUP BY s.ip HAVING count( e.itemid ) >0 LIMIT 0 , 30;
ip	count( e.itemid )
10.10.10.1	1
drop tables t1,t2;
create table t1 (fld enum('0','1'));
insert into t1 values ('1');
select * from (select max(fld) from t1) as foo;
max(fld)
1
drop table t1;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
SET optimizer_switch='semijoin_with_cache=off';
CREATE TABLE t1 (one int, two int, flag char(1));
CREATE TABLE t2 (one int, two int, flag char(1));
INSERT INTO t1 VALUES(1,2,'Y'),(2,3,'Y'),(3,4,'Y'),(5,6,'N'),(7,8,'N');
INSERT INTO t2 VALUES(1,2,'Y'),(2,3,'Y'),(3,4,'Y'),(5,6,'N'),(7,8,'N');
SELECT * FROM t1
WHERE ROW(one,two) IN (SELECT DISTINCT one,two FROM t2 WHERE flag = 'N');
one	two	flag
5	6	N
7	8	N
SELECT * FROM t1
WHERE ROW(one,two) IN (SELECT DISTINCT one,two FROM t1 WHERE flag = 'N');
one	two	flag
5	6	N
7	8	N
insert into t2 values (null,null,'N');
insert into t2 values (null,3,'0');
insert into t2 values (null,5,'0');
insert into t2 values (10,null,'0');
insert into t1 values (10,3,'0');
insert into t1 values (10,5,'0');
insert into t1 values (10,10,'0');
SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N') as 'test' from t1;
one	two	test
1	2	NULL
2	3	NULL
3	4	NULL
5	6	1
7	8	1
10	3	NULL
10	5	NULL
10	10	NULL
SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N');
one	two
5	6
7	8
SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N' group by one,two) as 'test' from t1;
one	two	test
1	2	NULL
2	3	NULL
3	4	NULL
5	6	1
7	8	1
10	3	NULL
10	5	NULL
10	10	NULL
SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = '0') as 'test' from t1;
one	two	test
1	2	0
2	3	NULL
3	4	0
5	6	0
7	8	0
10	3	NULL
10	5	NULL
10	10	NULL
SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = '0' group by one,two) as 'test' from t1;
one	two	test
1	2	0
2	3	NULL
3	4	0
5	6	0
7	8	0
10	3	NULL
10	5	NULL
10	10	NULL
explain extended SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = '0') as 'test' from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
Warnings:
Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
explain extended SELECT one,two from t1 where ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = 'N');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	8	func,func	1	100.00	
2	MATERIALIZED	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
Warnings:
Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`flag` = 'N'))
explain extended SELECT one,two,ROW(one,two) IN (SELECT one,two FROM t2 WHERE flag = '0' group by one,two) as 'test' from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	8	100.00	
2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	9	100.00	Using where
Warnings:
Note	1003	select `test`.`t1`.`one` AS `one`,`test`.`t1`.`two` AS `two`,<expr_cache><`test`.`t1`.`one`,`test`.`t1`.`two`>(<in_optimizer>((`test`.`t1`.`one`,`test`.`t1`.`two`),<exists>(select `test`.`t2`.`one`,`test`.`t2`.`two` from `test`.`t2` where ((`test`.`t2`.`flag` = '0') and trigcond(((<cache>(`test`.`t1`.`one`) = `test`.`t2`.`one`) or isnull(`test`.`t2`.`one`))) and trigcond(((<cache>(`test`.`t1`.`two`) = `test`.`t2`.`two`) or isnull(`test`.`t2`.`two`)))) having (trigcond(<is_not_null_test>(`test`.`t2`.`one`)) and trigcond(<is_not_null_test>(`test`.`t2`.`two`)))))) AS `test` from `test`.`t1`
DROP TABLE t1,t2;
set @@optimizer_switch=@save_optimizer_switch;
CREATE TABLE t1 (a char(5), b char(5));
INSERT INTO t1 VALUES (NULL,'aaa'), ('aaa','aaa');
SELECT * FROM t1 WHERE (a,b) IN (('aaa','aaa'), ('aaa','bbb'));
a	b
aaa	aaa
DROP TABLE t1;
CREATE TABLE t1 (a int);
CREATE TABLE t2 (a int, b int);
CREATE TABLE t3 (b int NOT NULL);
INSERT INTO t1 VALUES (1), (2), (3), (4);
INSERT INTO t2 VALUES (1,10), (3,30);
SELECT * FROM t2 LEFT JOIN t3 ON t2.b=t3.b
WHERE t3.b IS NOT NULL OR t2.a > 10;
a	b	b
SELECT * FROM t1
WHERE t1.a NOT IN (SELECT a FROM t2 LEFT JOIN t3 ON t2.b=t3.b
WHERE t3.b IS NOT NULL OR t2.a > 10);
a
1
2
3
4
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (f1 INT);
CREATE TABLE t2 (f2 INT);
INSERT INTO t1 VALUES (1);
SELECT * FROM t1 WHERE f1 > ALL (SELECT f2 FROM t2);
f1
1
SELECT * FROM t1 WHERE f1 > ALL (SELECT f2 FROM t2 WHERE 1=0);
f1
1
INSERT INTO t2 VALUES (1);
INSERT INTO t2 VALUES (2);
SELECT * FROM t1 WHERE f1 > ALL (SELECT f2 FROM t2 WHERE f2=0);
f1
1
DROP TABLE t1, t2;
select 1 from dual where 1 < any (select 2);
1
1
select 1 from dual where 1 < all (select 2);
1
1
select 1 from dual where 2 > any (select 1);
1
1
select 1 from dual where 2 > all (select 1);
1
1
select 1 from dual where 1 < any (select 2 from dual);
1
1
select 1 from dual where 1 < all (select 2 from dual where 1!=1);
1
1
create table t1 (s1 char);
insert into t1 values (1),(2);
select * from t1 where (s1 < any (select s1 from t1));
s1
1
select * from t1 where not (s1 < any (select s1 from t1));
s1
2
select * from t1 where (s1 < ALL (select s1+1 from t1));
s1
1
select * from t1 where not(s1 < ALL (select s1+1 from t1));
s1
2
select * from t1 where (s1+1 = ANY (select s1 from t1));
s1
1
select * from t1 where NOT(s1+1 = ANY (select s1 from t1));
s1
2
select * from t1 where (s1 = ALL (select s1/s1 from t1));
s1
1
select * from t1 where NOT(s1 = ALL (select s1/s1 from t1));
s1
2
drop table t1;
create table t1 (
retailerID varchar(8) NOT NULL,
statusID   int(10) unsigned NOT NULL,
changed    datetime NOT NULL,
UNIQUE KEY retailerID (retailerID, statusID, changed)
);
INSERT INTO t1 VALUES("0026", "1", "2005-12-06 12:18:56");
INSERT INTO t1 VALUES("0026", "2", "2006-01-06 12:25:53");
INSERT INTO t1 VALUES("0037", "1", "2005-12-06 12:18:56");
INSERT INTO t1 VALUES("0037", "2", "2006-01-06 12:25:53");
INSERT INTO t1 VALUES("0048", "1", "2006-01-06 12:37:50");
INSERT INTO t1 VALUES("0059", "1", "2006-01-06 12:37:50");
select * from t1 r1 
where (r1.retailerID,(r1.changed)) in 
(SELECT r2.retailerId,(max(changed)) from t1 r2 
group by r2.retailerId);
retailerID	statusID	changed
0026	2	2006-01-06 12:25:53
0037	2	2006-01-06 12:25:53
0048	1	2006-01-06 12:37:50
0059	1	2006-01-06 12:37:50
drop table t1;
create table t1(a int, primary key (a));
insert into t1 values (10);
create table t2 (a int primary key, b varchar(32), c int, unique key b(c, b));
insert into t2(a, c, b) values (1,10,'359'), (2,10,'35988'), (3,10,'35989');
explain SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r 
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899' 
ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	Using index
1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	1	Using where
SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r 
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899' 
ORDER BY t2.c DESC, t2.b DESC LIMIT 1) WHERE t1.a = 10;
a	a	b
10	3	35989
explain SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r 
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899' 
ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	Using index
1	PRIMARY	r	eq_ref	PRIMARY	PRIMARY	4	const	1	Using where
2	DEPENDENT SUBQUERY	t2	range	b	b	40	NULL	1	Using where
SELECT sql_no_cache t1.a, r.a, r.b FROM t1 LEFT JOIN t2 r 
ON r.a = (SELECT t2.a FROM t2 WHERE t2.c = t1.a AND t2.b <= '359899' 
ORDER BY t2.c, t2.b LIMIT 1) WHERE t1.a = 10;
a	a	b
10	1	359
drop table t1,t2;
CREATE TABLE t1 (                  
field1 int NOT NULL,                 
field2 int NOT NULL,                 
field3 int NOT NULL,                 
PRIMARY KEY  (field1,field2,field3)  
);
CREATE TABLE t2 (             
fieldA int NOT NULL,            
fieldB int NOT NULL,            
PRIMARY KEY  (fieldA,fieldB)     
);
INSERT INTO t1 VALUES
(1,1,1), (1,1,2), (1,2,1), (1,2,2), (1,2,3), (1,3,1);
INSERT INTO t2 VALUES (1,1), (1,2), (1,3);
SELECT field1, field2, COUNT(*)
FROM t1 GROUP BY field1, field2;
field1	field2	COUNT(*)
1	1	2
1	2	3
1	3	1
SELECT field1, field2
FROM  t1
GROUP BY field1, field2
HAVING COUNT(*) >= ALL (SELECT fieldB 
FROM t2 WHERE fieldA = field1);
field1	field2
1	2
SELECT field1, field2
FROM  t1
GROUP BY field1, field2
HAVING COUNT(*) < ANY (SELECT fieldB 
FROM t2 WHERE fieldA = field1);
field1	field2
1	1
1	3
DROP TABLE t1, t2;
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=off";
CREATE TABLE t1(a int, INDEX (a));
INSERT INTO t1 VALUES (1), (3), (5), (7);
INSERT INTO t1 VALUES (NULL);
CREATE TABLE t2(a int);
INSERT INTO t2 VALUES (1),(2),(3);
EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	
2	DEPENDENT SUBQUERY	t1	index_subquery	a	a	5	func	2	Using index; Full scan on NULL key
SELECT a, a IN (SELECT a FROM t1) FROM t2;
a	a IN (SELECT a FROM t1)
1	1
2	NULL
3	1
DROP TABLE t1,t2;
set @@optimizer_switch=@save_optimizer_switch;
CREATE TABLE t1 (a DATETIME);
INSERT INTO t1 VALUES ('1998-09-23'), ('2003-03-25');
CREATE TABLE t2 AS SELECT 
(SELECT a FROM t1 WHERE a < '2000-01-01') AS sub_a 
FROM t1 WHERE a > '2000-01-01';
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `sub_a` datetime DEFAULT NULL
) ENGINE=PBXT DEFAULT CHARSET=latin1
CREATE TABLE t3 AS (SELECT a FROM t1 WHERE a < '2000-01-01') UNION (SELECT a FROM t1 WHERE a > '2000-01-01');
SHOW CREATE TABLE t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `a` datetime DEFAULT NULL
) ENGINE=PBXT DEFAULT CHARSET=latin1
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (1), (2);
SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) > 0;
a
SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) IS NULL;
a
1
2
EXPLAIN SELECT a FROM t1 WHERE (SELECT 1 FROM DUAL WHERE 1=0) IS NULL;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
2	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
DROP TABLE t1;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (2), (4), (1), (3);
CREATE TABLE t2 (b int, c int);
INSERT INTO t2 VALUES
(2,1), (1,3), (2,1), (4,4), (2,2), (1,4);
SELECT a FROM t1 ORDER BY (SELECT c FROM t2 WHERE b > 2 );
a
2
4
1
3
SELECT a FROM t1 ORDER BY (SELECT c FROM t2 WHERE b > 1);
ERROR 21000: Subquery returns more than 1 row
SELECT a FROM t1 ORDER BY (SELECT c FROM t2 WHERE b > 2), a;
a
1
2
3
4
SELECT a FROM t1 ORDER BY (SELECT c FROM t2 WHERE b > 1), a;
ERROR 21000: Subquery returns more than 1 row
SELECT b, MAX(c) FROM t2 GROUP BY b, (SELECT c FROM t2 WHERE b > 2);
b	MAX(c)
1	4
2	2
4	4
SELECT b, MAX(c) FROM t2 GROUP BY b, (SELECT c FROM t2 WHERE b > 1);
ERROR 21000: Subquery returns more than 1 row
SELECT a FROM t1 GROUP BY a
HAVING IFNULL((SELECT b FROM t2 WHERE b > 2),
(SELECT c FROM t2 WHERE c=a AND b > 2 ORDER BY b)) > 3;
a
1
2
3
4
SELECT a FROM t1 GROUP BY a
HAVING IFNULL((SELECT b FROM t2 WHERE b > 1),
(SELECT c FROM t2 WHERE c=a AND b > 2 ORDER BY b)) > 3;
ERROR 21000: Subquery returns more than 1 row
SELECT a FROM t1 GROUP BY a
HAVING IFNULL((SELECT b FROM t2 WHERE b > 4),
(SELECT c FROM t2 WHERE c=a AND b > 2 ORDER BY b)) > 3;
a
4
SELECT a FROM t1 GROUP BY a
HAVING IFNULL((SELECT b FROM t2 WHERE b > 4),
(SELECT c FROM t2 WHERE c=a AND b > 1 ORDER BY b)) > 3;
ERROR 21000: Subquery returns more than 1 row
SELECT a FROM t1
ORDER BY IFNULL((SELECT b FROM t2 WHERE b > 2),
(SELECT c FROM t2 WHERE c=a AND b > 2 ORDER BY b));
a
1
2
3
4
SELECT a FROM t1
ORDER BY IFNULL((SELECT b FROM t2 WHERE b > 1),
(SELECT c FROM t2 WHERE c=a AND b > 1 ORDER BY b));
ERROR 21000: Subquery returns more than 1 row
SELECT a FROM t1
ORDER BY IFNULL((SELECT b FROM t2 WHERE b > 4),
(SELECT c FROM t2 WHERE c=a AND b > 2 ORDER BY b));
a
1
2
3
4
SELECT a FROM t1
ORDER BY IFNULL((SELECT b FROM t2 WHERE b > 4),
(SELECT c FROM t2 WHERE c=a AND b > 1 ORDER BY b));
ERROR 21000: Subquery returns more than 1 row
DROP TABLE t1,t2;
create table t1 (df decimal(5,1));
insert into t1 values(1.1);
insert into t1 values(2.2);
select * from t1 where df <= all (select avg(df) from t1 group by df);
df
1.1
select * from t1 where df >= all (select avg(df) from t1 group by df);
df
2.2
drop table t1;
create table t1 (df decimal(5,1));
insert into t1 values(1.1);
select 1.1 * exists(select * from t1);
1.1 * exists(select * from t1)
1.1
drop table t1;
CREATE TABLE t1 (
grp int(11) default NULL,
a decimal(10,2) default NULL);
insert into t1 values (1, 1), (2, 2), (2, 3), (3, 4), (3, 5), (3, 6), (NULL, NULL);
select * from t1;
grp	a
1	1.00
2	2.00
2	3.00
3	4.00
3	5.00
3	6.00
NULL	NULL
select min(a) from t1 group by grp;
min(a)
NULL
1.00
2.00
4.00
drop table t1;
CREATE table t1 ( c1 integer );
INSERT INTO t1 VALUES ( 1 );
INSERT INTO t1 VALUES ( 2 );
INSERT INTO t1 VALUES ( 3 );
CREATE TABLE t2 ( c2 integer );
INSERT INTO t2 VALUES ( 1 );
INSERT INTO t2 VALUES ( 4 );
INSERT INTO t2 VALUES ( 5 );
SELECT * FROM t1 LEFT JOIN t2 ON c1 = c2 WHERE c2 IN (1);
c1	c2
1	1
SELECT * FROM t1 LEFT JOIN t2 ON c1 = c2
WHERE c2 IN ( SELECT c2 FROM t2 WHERE c2 IN ( 1 ) );
c1	c2
1	1
DROP TABLE t1,t2;
CREATE TABLE t1 ( c1 integer );
INSERT INTO t1 VALUES ( 1 );
INSERT INTO t1 VALUES ( 2 );
INSERT INTO t1 VALUES ( 3 );
INSERT INTO t1 VALUES ( 6 );
CREATE TABLE t2 ( c2 integer );
INSERT INTO t2 VALUES ( 1 );
INSERT INTO t2 VALUES ( 4 );
INSERT INTO t2 VALUES ( 5 );
INSERT INTO t2 VALUES ( 6 );
CREATE TABLE t3 ( c3 integer );
INSERT INTO t3 VALUES ( 7 );
INSERT INTO t3 VALUES ( 8 );
SELECT c1,c2 FROM t1 LEFT JOIN t2 ON c1 = c2 
WHERE EXISTS (SELECT c3 FROM t3 WHERE c2 IS NULL );
c1	c2
2	NULL
3	NULL
DROP TABLE t1,t2,t3;
CREATE TABLE `t1` (
`itemid` bigint(20) unsigned NOT NULL auto_increment,
`sessionid` bigint(20) unsigned default NULL,
`time` int(10) unsigned NOT NULL default '0',
`type` set('A','D','E','F','G','I','L','N','U') collate latin1_general_ci NOT
NULL default '',
`data` text collate latin1_general_ci NOT NULL,
PRIMARY KEY  (`itemid`)
) DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;
INSERT INTO `t1` VALUES (1, 1, 1, 'D', '');
CREATE TABLE `t2` (
`sessionid` bigint(20) unsigned NOT NULL auto_increment,
`pid` int(10) unsigned NOT NULL default '0',
`date` int(10) unsigned NOT NULL default '0',
`ip` varchar(15) collate latin1_general_ci NOT NULL default '',
PRIMARY KEY  (`sessionid`)
) DEFAULT CHARSET=latin1 COLLATE=latin1_general_ci;
INSERT INTO `t2` VALUES (1, 1, 1, '10.10.10.1');
SELECT s.ip, count( e.itemid ) FROM `t1` e JOIN t2 s ON s.sessionid = e.sessionid WHERE e.sessionid = ( SELECT sessionid FROM t2 ORDER BY sessionid DESC LIMIT 1 ) GROUP BY s.ip HAVING count( e.itemid ) >0 LIMIT 0 , 30;
ip	count( e.itemid )
10.10.10.1	1
drop tables t1,t2;
CREATE TABLE t1 (EMPNUM   CHAR(3));
CREATE TABLE t2 (EMPNUM   CHAR(3) );
INSERT INTO t1 VALUES ('E1'),('E2');
INSERT INTO t2 VALUES ('E1');
DELETE FROM t1
WHERE t1.EMPNUM NOT IN
(SELECT t2.EMPNUM
FROM t2
WHERE t1.EMPNUM = t2.EMPNUM);
select * from t1;
EMPNUM
E1
DROP TABLE t1,t2;
CREATE TABLE t1(select_id BIGINT, values_id BIGINT);
INSERT INTO t1 VALUES (1, 1);
CREATE TABLE t2 (select_id BIGINT, values_id BIGINT, 
PRIMARY KEY(select_id,values_id));
INSERT INTO t2 VALUES (0, 1), (0, 2), (0, 3), (1, 5);
SELECT values_id FROM t1 
WHERE values_id IN (SELECT values_id FROM t2
WHERE select_id IN (1, 0));
values_id
1
SELECT values_id FROM t1 
WHERE values_id IN (SELECT values_id FROM t2
WHERE select_id BETWEEN 0 AND 1);
values_id
1
SELECT values_id FROM t1 
WHERE values_id IN (SELECT values_id FROM t2
WHERE select_id = 0 OR select_id = 1);
values_id
1
DROP TABLE t1, t2;
create table t1 (fld enum('0','1'));
insert into t1 values ('1');
select * from (select max(fld) from t1) as foo;
max(fld)
1
drop table t1;
CREATE TABLE t1 (a int, b int);
CREATE TABLE t2 (c int, d int);
CREATE TABLE t3 (e int);
INSERT INTO t1 VALUES 
(1,10), (2,10), (1,20), (2,20), (3,20), (2,30), (4,40);
INSERT INTO t2 VALUES
(2,10), (2,20), (4,10), (5,10), (3,20), (2,40);
INSERT INTO t3 VALUES (10), (30), (10), (20) ;
SELECT a, MAX(b), MIN(b) FROM t1 GROUP BY a;
a	MAX(b)	MIN(b)
1	20	10
2	30	10
3	20	20
4	40	40
SELECT * FROM t2;
c	d
2	10
2	20
4	10
5	10
3	20
2	40
SELECT * FROM t3;
e
10
30
10
20
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2 WHERE MAX(b)>20);
a
2
4
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2 WHERE MAX(b)<d);
a
2
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2 WHERE MAX(b)>d);
a
2
4
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2
WHERE d >= SOME(SELECT e FROM t3 WHERE MAX(b)=e));
a
2
3
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2
WHERE  EXISTS(SELECT e FROM t3 WHERE MAX(b)=e AND e <= d));
a
2
3
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2
WHERE d > SOME(SELECT e FROM t3 WHERE MAX(b)=e));
a
2
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2
WHERE  EXISTS(SELECT e FROM t3 WHERE MAX(b)=e AND e < d));
a
2
SELECT a FROM t1 GROUP BY a
HAVING a IN (SELECT c FROM t2
WHERE MIN(b) < d AND 
EXISTS(SELECT e FROM t3 WHERE MAX(b)=e AND e <= d));
a
2
SELECT a, SUM(a) FROM t1 GROUP BY a;
a	SUM(a)
1	2
2	6
3	3
4	4
SELECT a FROM t1
WHERE EXISTS(SELECT c FROM t2 GROUP BY c HAVING SUM(a) = c) GROUP BY a;
a
3
4
SELECT a FROM t1 GROUP BY a
HAVING EXISTS(SELECT c FROM t2 GROUP BY c HAVING SUM(a) = c);
a
1
3
4
SELECT a FROM t1
WHERE a < 3 AND
EXISTS(SELECT c FROM t2 GROUP BY c HAVING SUM(a) != c) GROUP BY a;
a
1
2
SELECT a FROM t1
WHERE a < 3 AND
EXISTS(SELECT c FROM t2 GROUP BY c HAVING SUM(a) != c);
a
1
2
1
2
2
SELECT t1.a FROM t1 GROUP BY t1.a
HAVING t1.a < ALL(SELECT t2.c FROM t2 GROUP BY t2.c
HAVING EXISTS(SELECT t3.e FROM t3 GROUP BY t3.e
HAVING SUM(t1.a+t2.c) < t3.e/4));
a
1
2
SELECT t1.a FROM t1 GROUP BY t1.a
HAVING t1.a > ALL(SELECT t2.c FROM t2
WHERE EXISTS(SELECT t3.e FROM t3 GROUP BY t3.e
HAVING SUM(t1.a+t2.c) < t3.e/4));
a
4
SELECT t1.a FROM t1 GROUP BY t1.a
HAVING t1.a > ALL(SELECT t2.c FROM t2
WHERE EXISTS(SELECT t3.e FROM t3 
WHERE SUM(t1.a+t2.c) < t3.e/4));
ERROR HY000: Invalid use of group function
SELECT t1.a from t1 GROUP BY t1.a HAVING AVG(SUM(t1.b)) > 20;
ERROR HY000: Invalid use of group function
SELECT t1.a FROM t1 GROUP BY t1.a
HAVING t1.a IN (SELECT t2.c FROM t2 GROUP BY t2.c
HAVING AVG(t2.c+SUM(t1.b)) > 20);
a
2
3
4
SELECT t1.a FROM t1 GROUP BY t1.a
HAVING t1.a IN (SELECT t2.c FROM t2 GROUP BY t2.c
HAVING AVG(SUM(t1.b)) > 20);
a
2
4
SELECT t1.a, SUM(b) AS sum  FROM t1 GROUP BY t1.a
HAVING t1.a IN (SELECT t2.c FROM t2 GROUP BY t2.c
HAVING t2.c+sum > 20);
a	sum
2	60
3	20
4	40
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (a varchar(5), b varchar(10));
INSERT INTO t1 VALUES
('AAA', 5), ('BBB', 4), ('BBB', 1), ('CCC', 2),
('CCC', 7), ('AAA', 2), ('AAA', 4), ('BBB', 3), ('AAA', 8);
SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
a	b
BBB	4
CCC	7
AAA	8
EXPLAIN
SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	9	Using where
1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
ALTER TABLE t1 ADD INDEX(a);
SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
a	b
BBB	4
CCC	7
AAA	8
EXPLAIN
SELECT * FROM t1 WHERE (a,b) = ANY (SELECT a, max(b) FROM t1 GROUP BY a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	a	NULL	NULL	NULL	9	Using where
1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	21	test.t1.a,test.t1.b	1	
2	MATERIALIZED	t1	ALL	NULL	NULL	NULL	NULL	9	Using temporary
DROP TABLE t1;
create table t1( f1 int,f2 int);
insert into t1 values (1,1),(2,2);
select tt.t from (select 'crash1' as t, f2 from t1) as tt left join t1 on tt.t = 'crash2' and tt.f2 = t1.f2 where tt.t = 'crash1';
t
crash1
crash1
drop table t1;
create table t1 (c int, key(c));
insert into t1 values (1142477582), (1142455969);
create table t2 (a int, b int);
insert into t2 values (2, 1), (1, 0);
delete from t1 where c <= 1140006215 and (select b from t2 where a = 2) = 1;
drop table t1, t2;
CREATE TABLE t1 (a INT);
CREATE VIEW v1 AS SELECT * FROM t1 WHERE no_such_column = ANY (SELECT 1);
ERROR 42S22: Unknown column 'no_such_column' in 'where clause'
CREATE VIEW v2 AS SELECT * FROM t1 WHERE no_such_column = (SELECT 1);
ERROR 42S22: Unknown column 'no_such_column' in 'where clause'
SELECT * FROM t1 WHERE no_such_column = ANY (SELECT 1);
ERROR 42S22: Unknown column 'no_such_column' in 'IN/ALL/ANY subquery'
DROP TABLE t1;
create table t1 (i int, j bigint);
insert into t1 values (1, 2), (2, 2), (3, 2);
select * from (select min(i) from t1 where j=(select * from (select min(j) from t1) t2)) t3;
min(i)
1
drop table t1;
CREATE TABLE t1 (i BIGINT UNSIGNED);
INSERT INTO t1 VALUES (10000000000000000000);
INSERT INTO t1 VALUES (1);
CREATE TABLE t2 (i BIGINT UNSIGNED);
INSERT INTO t2 VALUES (10000000000000000000);
INSERT INTO t2 VALUES (1);
/* simple test */
SELECT t1.i FROM t1 JOIN t2 ON t1.i = t2.i;
i
10000000000000000000
1
/* subquery test */
SELECT t1.i FROM t1 WHERE t1.i = (SELECT MAX(i) FROM t2);
i
10000000000000000000
/* subquery test with cast*/
SELECT t1.i FROM t1 WHERE t1.i = CAST((SELECT MAX(i) FROM t2) AS UNSIGNED);
i
10000000000000000000
DROP TABLE t1;
DROP TABLE t2;
CREATE TABLE t1 (
id bigint(20) unsigned NOT NULL auto_increment,
name varchar(255) NOT NULL,
PRIMARY KEY  (id)
);
INSERT INTO t1 VALUES
(1, 'Balazs'), (2, 'Joe'), (3, 'Frank');
CREATE TABLE t2 (
id bigint(20) unsigned NOT NULL auto_increment,
mid bigint(20) unsigned NOT NULL,
date date NOT NULL,
PRIMARY KEY  (id)
);
INSERT INTO t2 VALUES 
(1, 1, '2006-03-30'), (2, 2, '2006-04-06'), (3, 3, '2006-04-13'),
(4, 2, '2006-04-20'), (5, 1, '2006-05-01');
SELECT *,
(SELECT date FROM t2 WHERE mid = t1.id
ORDER BY date DESC LIMIT 0, 1) AS date_last,
(SELECT date FROM t2 WHERE mid = t1.id
ORDER BY date DESC LIMIT 3, 1) AS date_next_to_last
FROM t1;
id	name	date_last	date_next_to_last
1	Balazs	2006-05-01	NULL
2	Joe	2006-04-20	NULL
3	Frank	2006-04-13	NULL
SELECT *,
(SELECT COUNT(*) FROM t2 WHERE mid = t1.id
ORDER BY date DESC LIMIT 1, 1) AS date_count
FROM t1;
id	name	date_count
1	Balazs	NULL
2	Joe	NULL
3	Frank	NULL
SELECT *,
(SELECT date FROM t2 WHERE mid = t1.id
ORDER BY date DESC LIMIT 0, 1) AS date_last,
(SELECT date FROM t2 WHERE mid = t1.id
ORDER BY date DESC LIMIT 1, 1) AS date_next_to_last
FROM t1;
id	name	date_last	date_next_to_last
1	Balazs	2006-05-01	2006-03-30
2	Joe	2006-04-20	2006-04-06
3	Frank	2006-04-13	NULL
DROP TABLE t1,t2;
CREATE TABLE t1 (
i1 int(11) NOT NULL default '0',
i2 int(11) NOT NULL default '0',
t datetime NOT NULL default '0000-00-00 00:00:00',
PRIMARY KEY  (i1,i2,t)
);
INSERT INTO t1 VALUES 
(24,1,'2005-03-03 16:31:31'),(24,1,'2005-05-27 12:40:07'),
(24,1,'2005-05-27 12:40:08'),(24,1,'2005-05-27 12:40:10'),
(24,1,'2005-05-27 12:40:25'),(24,1,'2005-05-27 12:40:30'),
(24,2,'2005-03-03 13:43:05'),(24,2,'2005-03-03 16:23:31'),
(24,2,'2005-03-03 16:31:30'),(24,2,'2005-05-27 12:37:02'),
(24,2,'2005-05-27 12:40:06');
CREATE TABLE t2 (
i1 int(11) NOT NULL default '0',
i2 int(11) NOT NULL default '0',
t datetime default NULL,
PRIMARY KEY  (i1)
);
INSERT INTO t2 VALUES (24,1,'2006-06-20 12:29:40');
EXPLAIN
SELECT * FROM t1,t2
WHERE t1.t = (SELECT t1.t FROM t1 
WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
ORDER BY t1.t DESC LIMIT 1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	
1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index; Using join buffer (flat, BNL join)
2	DEPENDENT SUBQUERY	t1	ref	PRIMARY	PRIMARY	8	test.t2.i1,const	1	Using where; Using index; Using filesort
SELECT * FROM t1,t2
WHERE t1.t = (SELECT t1.t FROM t1 
WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
ORDER BY t1.t DESC LIMIT 1);
i1	i2	t	i1	i2	t
24	1	2005-05-27 12:40:30	24	1	2006-06-20 12:29:40
DROP TABLE t1, t2;
CREATE TABLE t1 (i INT);
(SELECT i FROM t1) UNION (SELECT i FROM t1);
i
SELECT sql_no_cache * FROM t1 WHERE NOT EXISTS 
(
(SELECT i FROM t1) UNION 
(SELECT i FROM t1)
);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UNION 
(SELECT i FROM t1)
)' at line 3
SELECT * FROM t1 
WHERE NOT EXISTS (((SELECT i FROM t1) UNION (SELECT i FROM t1)));
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UNION (SELECT i FROM t1)))' at line 2
explain select ((select t11.i from t1 t11) union (select t12.i from t1 t12))
from t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'union (select t12.i from t1 t12))
from t1' at line 1
explain select * from t1 where not exists 
((select t11.i from t1 t11) union (select t12.i from t1 t12));
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'union (select t12.i from t1 t12))' at line 2
DROP TABLE t1;
CREATE TABLE t1 (a VARCHAR(250), b INT auto_increment, PRIMARY KEY (b));
insert into t1 (a) values (FLOOR(rand() * 100));
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
insert into t1 (a) select FLOOR(rand() * 100) from t1;
SELECT a, 
(SELECT REPEAT(' ',250) FROM t1 i1 
WHERE i1.b=t1.a ORDER BY RAND() LIMIT 1) AS a 
FROM t1 ORDER BY a LIMIT 5;
a	a
0	NULL
0	NULL
0	NULL
0	NULL
0	NULL
DROP TABLE t1;
CREATE TABLE t1 (a INT, b INT);
CREATE TABLE t2 (a INT);
INSERT INTO t2 values (1);
INSERT INTO t1 VALUES (1,1),(1,2),(2,3),(3,4);
SELECT (SELECT COUNT(DISTINCT t1.b) from t2) FROM t1 GROUP BY t1.a;
(SELECT COUNT(DISTINCT t1.b) from t2)
2
1
1
SELECT (SELECT COUNT(DISTINCT t1.b) from t2 union select 1 from t2 where 12 < 3)
FROM t1 GROUP BY t1.a;
(SELECT COUNT(DISTINCT t1.b) from t2 union select 1 from t2 where 12 < 3)
2
1
1
SELECT COUNT(DISTINCT t1.b), (SELECT COUNT(DISTINCT t1.b)) FROM t1 GROUP BY t1.a;
COUNT(DISTINCT t1.b)	(SELECT COUNT(DISTINCT t1.b))
2	2
1	1
1	1
SELECT COUNT(DISTINCT t1.b), 
(SELECT COUNT(DISTINCT t1.b) union select 1 from DUAL where 12 < 3)
FROM t1 GROUP BY t1.a;
COUNT(DISTINCT t1.b)	(SELECT COUNT(DISTINCT t1.b) union select 1 from DUAL where 12 < 3)
2	2
1	1
1	1
SELECT (
SELECT (
SELECT COUNT(DISTINCT t1.b)
)
) 
FROM t1 GROUP BY t1.a;
(
SELECT (
SELECT COUNT(DISTINCT t1.b)
)
)
2
1
1
SELECT (
SELECT (
SELECT (
SELECT COUNT(DISTINCT t1.b)
)
) 
FROM t1 GROUP BY t1.a LIMIT 1) 
FROM t1 t2
GROUP BY t2.a;
(
SELECT (
SELECT (
SELECT COUNT(DISTINCT t1.b)
)
) 
FROM t1 GROUP BY t1.a LIMIT 1)
2
2
2
DROP TABLE t1,t2;
CREATE TABLE t1 (a int, b int auto_increment, PRIMARY KEY (b));
CREATE TABLE t2 (x int auto_increment, y int, z int,
PRIMARY KEY (x), FOREIGN KEY (y) REFERENCES t1 (b));
SET SESSION sort_buffer_size = 32 * 1024;
SELECT SQL_NO_CACHE COUNT(*) 
FROM (SELECT  a, b, (SELECT x FROM t2 WHERE y=b ORDER BY z DESC LIMIT 1) c
FROM t1) t;
COUNT(*)
3000
SET SESSION sort_buffer_size = 8 * 1024 * 1024;
SELECT SQL_NO_CACHE COUNT(*) 
FROM (SELECT  a, b, (SELECT x FROM t2 WHERE y=b ORDER BY z DESC LIMIT 1) c
FROM t1) t;
COUNT(*)
3000
DROP TABLE t2,t1;
CREATE TABLE t1 (id char(4) PRIMARY KEY, c int);
CREATE TABLE t2 (c int);
INSERT INTO t1 VALUES ('aa', 1);
INSERT INTO t2 VALUES (1);
SELECT * FROM t1
WHERE EXISTS (SELECT c FROM t2 WHERE c=1
UNION
SELECT c from t2 WHERE c=t1.c);
id	c
aa	1
INSERT INTO t1 VALUES ('bb', 2), ('cc', 3), ('dd',1);
SELECT * FROM t1
WHERE EXISTS (SELECT c FROM t2 WHERE c=1
UNION
SELECT c from t2 WHERE c=t1.c);
id	c
aa	1
bb	2
cc	3
dd	1
INSERT INTO t2 VALUES (2);
CREATE TABLE t3 (c int);
INSERT INTO t3 VALUES (1);
SELECT * FROM t1
WHERE EXISTS (SELECT t2.c FROM t2 JOIN t3 ON t2.c=t3.c WHERE t2.c=1
UNION
SELECT c from t2 WHERE c=t1.c);
id	c
aa	1
bb	2
cc	3
dd	1
DROP TABLE t1,t2,t3;
CREATE TABLE t1(f1 int);
CREATE TABLE t2(f2 int, f21 int, f3 timestamp);
INSERT INTO t1 VALUES (1),(1),(2),(2);
INSERT INTO t2 VALUES (1,1,"2004-02-29 11:11:11"), (2,2,"2004-02-29 11:11:11");
SELECT ((SELECT f2 FROM t2 WHERE f21=f1 LIMIT 1) * COUNT(f1)) AS sq FROM t1 GROUP BY f1;
sq
2
4
SELECT (SELECT SUM(1) FROM t2 ttt GROUP BY t2.f3 LIMIT 1) AS tt FROM t2;
tt
2
2
PREPARE stmt1 FROM 'SELECT ((SELECT f2 FROM t2 WHERE f21=f1 LIMIT 1) * COUNT(f1)) AS sq FROM t1 GROUP BY f1';
EXECUTE stmt1;
sq
2
4
EXECUTE stmt1;
sq
2
4
DEALLOCATE PREPARE stmt1;
SELECT f2, AVG(f21), 
(SELECT t.f3 FROM t2 AS t WHERE t2.f2=t.f2 AND t.f3=MAX(t2.f3)) AS test
FROM t2 GROUP BY f2;
f2	AVG(f21)	test
1	1.0000	2004-02-29 11:11:11
2	2.0000	2004-02-29 11:11:11
DROP TABLE t1,t2;
CREATE TABLE t1 (a int, b INT, c CHAR(10) NOT NULL);
INSERT INTO t1 VALUES                                                         
(1,1,'a'), (1,2,'b'), (1,3,'c'), (1,4,'d'), (1,5,'e'),                      
(2,1,'f'), (2,2,'g'), (2,3,'h'), (3,4,'i'), (3,3,'j'),                      
(3,2,'k'), (3,1,'l'), (1,9,'m');
SELECT a, MAX(b),                                                             
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b)) AS test      
FROM t1 GROUP BY a;
a	MAX(b)	test
1	9	m
2	3	h
3	4	i
DROP TABLE t1;
DROP TABLE IF EXISTS t1;
DROP TABLE IF EXISTS t2;
DROP TABLE IF EXISTS t1xt2;
CREATE TABLE t1 (
id_1 int(5) NOT NULL,
t varchar(4) DEFAULT NULL
);
CREATE TABLE t2 (
id_2 int(5) NOT NULL,
t varchar(4) DEFAULT NULL
);
CREATE TABLE t1xt2 (
id_1 int(5) NOT NULL,
id_2 int(5) NOT NULL
);
INSERT INTO t1 VALUES (1, 'a'), (2, 'b'), (3, 'c'), (4, 'd');
INSERT INTO t2 VALUES (2, 'bb'), (3, 'cc'), (4, 'dd'), (12, 'aa');
INSERT INTO t1xt2 VALUES (2, 2), (3, 3), (4, 4);
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN (SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1));
id_1
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN ((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1)));
id_1
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN (((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1))));
id_1
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN (SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1));
id_1
1
2
3
4
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN ((SELECT t1xt2.id_2 FROM t1xt2 where t1.id_1 = t1xt2.id_1)));
id_1
1
2
3
4
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN (((SELECT t1xt2.id_2 FROM t1xt2 where t1.id_1 = t1xt2.id_1))));
id_1
1
2
3
4
insert INTO t1xt2 VALUES (1, 12);
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN (SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1));
id_1
1
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN ((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1)));
id_1
1
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN (((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1))));
id_1
1
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN (SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1));
id_1
2
3
4
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN ((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1)));
id_1
2
3
4
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN (((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1))));
id_1
2
3
4
insert INTO t1xt2 VALUES (2, 12);
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN (SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1));
id_1
1
2
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN ((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1)));
id_1
1
2
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 IN (((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1))));
id_1
1
2
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN (SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1));
id_1
3
4
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN ((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1)));
id_1
3
4
SELECT DISTINCT t1.id_1 FROM t1 WHERE
(12 NOT IN (((SELECT t1xt2.id_2 FROM t1xt2 WHERE t1.id_1 = t1xt2.id_1))));
id_1
3
4
DROP TABLE t1;
DROP TABLE t2;
DROP TABLE t1xt2;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (3), (1), (2);
SELECT 'this is ' 'a test.' AS col1, a AS col2 FROM t1;
col1	col2
this is a test.	3
this is a test.	1
this is a test.	2
SELECT * FROM (SELECT 'this is ' 'a test.' AS col1, a AS t2 FROM t1) t;
col1	t2
this is a test.	3
this is a test.	1
this is a test.	2
DROP table t1;
CREATE TABLE t1 (a int, b int);
CREATE TABLE t2 (m int, n int);
INSERT INTO t1 VALUES (2,2), (2,2), (3,3), (3,3), (3,3), (4,4);
INSERT INTO t2 VALUES (1,11), (2,22), (3,32), (4,44), (4,44);
SELECT COUNT(*), a,
(SELECT m FROM t2 WHERE m = count(*) LIMIT 1)
FROM t1 GROUP BY a;
COUNT(*)	a	(SELECT m FROM t2 WHERE m = count(*) LIMIT 1)
2	2	2
3	3	3
1	4	1
SELECT COUNT(*), a,
(SELECT MIN(m) FROM t2 WHERE m = count(*))
FROM t1 GROUP BY a;
COUNT(*)	a	(SELECT MIN(m) FROM t2 WHERE m = count(*))
2	2	2
3	3	3
1	4	1
SELECT COUNT(*), a       
FROM t1 GROUP BY a
HAVING (SELECT MIN(m) FROM t2 WHERE m = count(*)) > 1;
COUNT(*)	a
2	2
3	3
DROP TABLE t1,t2;
CREATE TABLE t1 (a int, b int);
CREATE TABLE t2 (m int, n int);
INSERT INTO t1 VALUES (2,2), (2,2), (3,3), (3,3), (3,3), (4,4);
INSERT INTO t2 VALUES (1,11), (2,22), (3,32), (4,44), (4,44);
SELECT COUNT(*) c, a,
(SELECT GROUP_CONCAT(COUNT(a)) FROM t2 WHERE m = a)
FROM t1 GROUP BY a;
c	a	(SELECT GROUP_CONCAT(COUNT(a)) FROM t2 WHERE m = a)
2	2	2
3	3	3
1	4	1,1
SELECT COUNT(*) c, a,
(SELECT GROUP_CONCAT(COUNT(a)+1) FROM t2 WHERE m = a)
FROM t1 GROUP BY a;
c	a	(SELECT GROUP_CONCAT(COUNT(a)+1) FROM t2 WHERE m = a)
2	2	3
3	3	4
1	4	2,2
DROP table t1,t2;
CREATE TABLE t1 (a int, b INT, d INT, c CHAR(10) NOT NULL, PRIMARY KEY (a, b));
INSERT INTO t1 VALUES (1,1,0,'a'), (1,2,0,'b'), (1,3,0,'c'), (1,4,0,'d'),
(1,5,0,'e'), (2,1,0,'f'), (2,2,0,'g'), (2,3,0,'h'), (3,4,0,'i'), (3,3,0,'j'),
(3,2,0,'k'), (3,1,0,'l'), (1,9,0,'m'), (1,0,10,'n'), (2,0,5,'o'), (3,0,7,'p');
SELECT a, MAX(b),
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b + 0)) as test 
FROM t1 GROUP BY a;
a	MAX(b)	test
1	9	m
2	3	h
3	4	i
SELECT a x, MAX(b),
(SELECT t.c FROM t1 AS t WHERE x=t.a AND t.b=MAX(t1.b + 0)) as test
FROM t1 GROUP BY a;
x	MAX(b)	test
1	9	m
2	3	h
3	4	i
SELECT a, AVG(b),
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=AVG(t1.b)) AS test
FROM t1 WHERE t1.d=0 GROUP BY a;
a	AVG(b)	test
1	4.0000	d
2	2.0000	g
3	2.5000	NULL
SELECT tt.a,
(SELECT (SELECT c FROM t1 as t WHERE t1.a=t.a AND t.d=MAX(t1.b + tt.a)
LIMIT 1) FROM t1 WHERE t1.a=tt.a GROUP BY a LIMIT 1) as test 
FROM t1 as tt;
a	test
1	n
1	n
1	n
1	n
1	n
1	n
1	n
2	o
2	o
2	o
2	o
3	p
3	p
3	p
3	p
3	p
SELECT tt.a,
(SELECT (SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.d=MAX(t1.b + tt.a)
LIMIT 1)
FROM t1 WHERE t1.a=tt.a GROUP BY a LIMIT 1) as test 
FROM t1 as tt GROUP BY tt.a;
a	test
1	n
2	o
3	p
SELECT tt.a, MAX(
(SELECT (SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.d=MAX(t1.b + tt.a)
LIMIT 1)
FROM t1 WHERE t1.a=tt.a GROUP BY a LIMIT 1)) as test 
FROM t1 as tt GROUP BY tt.a;
a	test
1	n
2	o
3	p
DROP TABLE t1;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES (2,22),(1,11),(2,22);
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 0 GROUP BY a;
a
1
2
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 1 GROUP BY a;
a
SELECT a FROM t1 t0
WHERE (SELECT COUNT(t0.b) FROM t1 t WHERE t.b>20) GROUP BY a;
a
1
2
SET @@sql_mode='ansi';
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 0 GROUP BY a;
ERROR HY000: Invalid use of group function
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 1 GROUP BY a;
ERROR HY000: Invalid use of group function
SELECT a FROM t1 t0
WHERE (SELECT COUNT(t0.b) FROM t1 t WHERE t.b>20) GROUP BY a;
ERROR HY000: Invalid use of group function
SET @@sql_mode=default;
DROP TABLE t1;
CREATE TABLE t1 (a INT);
INSERT INTO t1 values (1),(1),(1),(1);
CREATE TABLE t2 (x INT);
INSERT INTO t1 values (1000),(1001),(1002);
SELECT SUM( (SELECT COUNT(a) FROM t2) ) FROM t1;
ERROR HY000: Invalid use of group function
SELECT SUM( (SELECT SUM(COUNT(a)) FROM t2) ) FROM t1;
ERROR HY000: Invalid use of group function
SELECT COUNT(1) FROM DUAL;
COUNT(1)
1
SELECT SUM( (SELECT AVG( (SELECT t1.a FROM t2) ) FROM DUAL) ) FROM t1;
ERROR HY000: Invalid use of group function
SELECT 
SUM( (SELECT AVG( (SELECT COUNT(*) FROM t1 t HAVING t1.a < 12) ) FROM t2) )
FROM t1;
ERROR HY000: Invalid use of group function
SELECT t1.a as XXA, 
SUM( (SELECT AVG( (SELECT COUNT(*) FROM t1 t HAVING XXA < 12) ) FROM t2) )
FROM t1;
ERROR HY000: Invalid use of group function
DROP TABLE t1,t2;
CREATE TABLE t1 (a int, b int, KEY (a));
INSERT INTO t1 VALUES (1,1),(2,1);
EXPLAIN SELECT 1 FROM t1 WHERE a = (SELECT COUNT(*) FROM t1 GROUP BY b);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ref	a	a	5	const	0	Using where; Using index
2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
DROP TABLE t1;
CREATE TABLE t1 (id int NOT NULL, st CHAR(2), INDEX idx(id));
INSERT INTO t1 VALUES
(3,'FL'), (2,'GA'), (4,'FL'), (1,'GA'), (5,'NY'), (7,'FL'), (6,'NY');
CREATE TABLE t2 (id int NOT NULL, INDEX idx(id));
INSERT INTO t2 VALUES (7), (5), (1), (3);
SELECT id, st FROM t1 
WHERE st IN ('GA','FL') AND EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id);
id	st
3	FL
1	GA
7	FL
SELECT id, st FROM t1 
WHERE st IN ('GA','FL') AND EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id)
GROUP BY id;
id	st
1	GA
3	FL
7	FL
SELECT id, st FROM t1 
WHERE st IN ('GA','FL') AND NOT EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id);
id	st
2	GA
4	FL
SELECT id, st FROM t1 
WHERE st IN ('GA','FL') AND NOT EXISTS(SELECT 1 FROM t2 WHERE t2.id=t1.id)
GROUP BY id;
id	st
2	GA
4	FL
DROP TABLE t1,t2;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (1), (2);
EXPLAIN EXTENDED
SELECT * FROM (SELECT count(*) FROM t1 GROUP BY a) as res;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
Warnings:
Note	1003	select `res`.`count(*)` AS `count(*)` from (select count(0) AS `count(*)` from `test`.`t1` group by `test`.`t1`.`a`) `res`
DROP TABLE t1;
CREATE TABLE t1 (
a varchar(255) default NULL,
b timestamp NOT NULL default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
INDEX idx(a,b)
);
CREATE TABLE t2 (
a varchar(255) default NULL
);
INSERT INTO t1 VALUES ('abcdefghijk','2007-05-07 06:00:24');
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO `t1` VALUES ('asdf','2007-02-08 01:11:26');
INSERT INTO `t2` VALUES ('abcdefghijk');
INSERT INTO `t2` VALUES ('asdf');
SET session sort_buffer_size=8192;
SELECT (SELECT 1 FROM  t1 WHERE t1.a=t2.a ORDER BY t1.b LIMIT 1) AS d1 FROM t2;
d1
1
1
DROP TABLE t1,t2;
CREATE TABLE t1 (a INTEGER, b INTEGER);
CREATE TABLE t2 (x INTEGER);
INSERT INTO t1 VALUES (1,11), (2,22), (2,22);
INSERT INTO t2 VALUES (1), (2);
SELECT a, COUNT(b), (SELECT COUNT(b) FROM t2) FROM t1 GROUP BY a;
ERROR 21000: Subquery returns more than 1 row
SELECT a, COUNT(b), (SELECT COUNT(b)+0 FROM t2) FROM t1 GROUP BY a;
ERROR 21000: Subquery returns more than 1 row
SELECT (SELECT SUM(t1.a)/AVG(t2.x) FROM t2) FROM t1;
(SELECT SUM(t1.a)/AVG(t2.x) FROM t2)
3.3333
DROP TABLE t1,t2;
CREATE TABLE t1 (a INT, b INT);
INSERT INTO t1 VALUES (1, 2), (1,3), (1,4), (2,1), (2,2);
SELECT a1.a, COUNT(*) FROM t1 a1 WHERE a1.a = 1
AND EXISTS( SELECT a2.a FROM t1 a2 WHERE a2.a = a1.a)
GROUP BY a1.a;
a	COUNT(*)
1	3
DROP TABLE t1;
CREATE TABLE t1 (a INT);
CREATE TABLE t2 (a INT);
INSERT INTO t1 VALUES (1),(2);
INSERT INTO t2 VALUES (1),(2);
SELECT (SELECT SUM(t1.a) FROM t2 WHERE a=0) FROM t1;
(SELECT SUM(t1.a) FROM t2 WHERE a=0)
NULL
SELECT (SELECT SUM(t1.a) FROM t2 WHERE a!=0) FROM t1;
ERROR 21000: Subquery returns more than 1 row
SELECT (SELECT SUM(t1.a) FROM t2 WHERE a=1) FROM t1;
(SELECT SUM(t1.a) FROM t2 WHERE a=1)
3
DROP TABLE t1,t2;
CREATE TABLE t1 (a1 INT, a2 INT);
CREATE TABLE t2 (b1 INT, b2 INT);
INSERT INTO t1 VALUES (100, 200);
INSERT INTO t1 VALUES (101, 201);
INSERT INTO t2 VALUES (101, 201);
INSERT INTO t2 VALUES (103, 203);
SELECT ((a1,a2) IN (SELECT * FROM t2 WHERE b2 > 0)) IS NULL FROM t1;
((a1,a2) IN (SELECT * FROM t2 WHERE b2 > 0)) IS NULL
0
0
DROP TABLE t1, t2;
CREATE TABLE t1 (s1 BINARY(5), s2 VARBINARY(5));
INSERT INTO t1 VALUES (0x41,0x41), (0x42,0x42), (0x43,0x43);
SELECT s1, s2 FROM t1 WHERE s2 IN (SELECT s1 FROM t1);
s1	s2
SELECT s1, s2 FROM t1 WHERE (s2, 10) IN (SELECT s1, 10 FROM t1);
s1	s2
CREATE INDEX I1 ON t1 (s1);
CREATE INDEX I2 ON t1 (s2);
SELECT s1, s2 FROM t1 WHERE s2 IN (SELECT s1 FROM t1);
s1	s2
SELECT s1, s2 FROM t1 WHERE (s2, 10) IN (SELECT s1, 10 FROM t1);
s1	s2
TRUNCATE t1;
INSERT INTO t1 VALUES (0x41,0x41);
SELECT * FROM t1 WHERE s1 = (SELECT s2 FROM t1);
s1	s2
DROP TABLE t1;
CREATE TABLE t1 (a1 VARBINARY(2) NOT NULL DEFAULT '0', PRIMARY KEY (a1));
CREATE TABLE t2 (a2 BINARY(2) default '0', INDEX (a2));
CREATE TABLE t3 (a3 BINARY(2) default '0');
INSERT INTO t1 VALUES (1),(2),(3),(4);
INSERT INTO t2 VALUES (1),(2),(3);
INSERT INTO t3 VALUES (1),(2),(3);
SELECT LEFT(t2.a2, 1) FROM t2,t3 WHERE t3.a3=t2.a2;
LEFT(t2.a2, 1)
1
2
3
SELECT t1.a1, t1.a1 in (SELECT t2.a2 FROM t2,t3 WHERE t3.a3=t2.a2) FROM t1;
a1	t1.a1 in (SELECT t2.a2 FROM t2,t3 WHERE t3.a3=t2.a2)
1	0
2	0
3	0
4	0
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (a1 BINARY(3) PRIMARY KEY, b1 VARBINARY(3));
CREATE TABLE t2 (a2 VARBINARY(3) PRIMARY KEY);
CREATE TABLE t3 (a3 VARBINARY(3) PRIMARY KEY);
INSERT INTO t1 VALUES (1,10), (2,20), (3,30), (4,40);
INSERT INTO t2 VALUES (2), (3), (4), (5);
INSERT INTO t3 VALUES (10), (20), (30);
SELECT LEFT(t1.a1,1) FROM t1,t3 WHERE t1.b1=t3.a3;
LEFT(t1.a1,1)
1
2
3
SELECT a2 FROM t2 WHERE t2.a2 IN (SELECT t1.a1 FROM t1,t3 WHERE t1.b1=t3.a3);
a2
DROP TABLE t1, t2, t3;
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='semijoin_with_cache=off';
SET optimizer_switch='materialization=off';
CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
INSERT INTO t1 VALUES ('a', 'aa');
INSERT INTO t1 VALUES ('a', 'aaa');
SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
a	b
CREATE INDEX I1 ON t1 (a);
CREATE INDEX I2 ON t1 (b);
EXPLAIN SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	I2	NULL	NULL	NULL	2	Using where
1	PRIMARY	t1	ref	I1	I1	2	test.t1.b	1	Using where; Using index; FirstMatch(t1)
SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1);
a	b
CREATE TABLE t2 (a VARCHAR(1), b VARCHAR(10));
INSERT INTO t2 SELECT * FROM t1;
CREATE INDEX I1 ON t2 (a);
CREATE INDEX I2 ON t2 (b);
EXPLAIN SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t2	ALL	I2	NULL	NULL	NULL	2	Using where
1	PRIMARY	t2	ref	I1	I1	4	test.t2.b	1	Using where; Using index; FirstMatch(t2)
SELECT a,b FROM t2 WHERE b IN (SELECT a FROM t2);
a	b
EXPLAIN
SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	I2	NULL	NULL	NULL	2	Using where
1	PRIMARY	t1	ref	I1	I1	2	test.t1.b	1	Using where; Using index; FirstMatch(t1)
SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
a	b
DROP TABLE t1,t2;
SET optimizer_switch= @save_optimizer_switch;
CREATE TABLE t1(a INT, b INT);
INSERT INTO t1 VALUES (1,1), (1,2), (2,3), (2,4);
EXPLAIN 
SELECT a AS out_a, MIN(b) FROM t1
WHERE b > (SELECT MIN(b) FROM t1 WHERE a = out_a)
GROUP BY a;
ERROR 42S22: Unknown column 'out_a' in 'where clause'
SELECT a AS out_a, MIN(b) FROM t1
WHERE b > (SELECT MIN(b) FROM t1 WHERE a = out_a)
GROUP BY a;
ERROR 42S22: Unknown column 'out_a' in 'where clause'
EXPLAIN 
SELECT a AS out_a, MIN(b) FROM t1 t1_outer
WHERE b > (SELECT MIN(b) FROM t1 WHERE a = t1_outer.a)
GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1_outer	ALL	NULL	NULL	NULL	NULL	4	Using where; Using temporary; Using filesort
2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
SELECT a AS out_a, MIN(b) FROM t1 t1_outer
WHERE b > (SELECT MIN(b) FROM t1 WHERE a = t1_outer.a)
GROUP BY a;
out_a	MIN(b)
1	2
2	4
DROP TABLE t1;
CREATE TABLE t1 (a INT);
CREATE TABLE t2 (a INT);
INSERT INTO t1 VALUES (1),(2);
INSERT INTO t2 VALUES (1),(2);
SELECT 2 FROM t1 WHERE EXISTS ((SELECT 1 FROM t2 WHERE t1.a=t2.a));
2
2
2
EXPLAIN EXTENDED
SELECT 2 FROM t1 WHERE EXISTS ((SELECT 1 FROM t2 WHERE t1.a=t2.a));
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
Warnings:
Note	1276	Field or reference 'test.t1.a' of SELECT #2 was resolved in SELECT #1
Note	1003	select 2 AS `2` from `test`.`t1` where <expr_cache><`test`.`t1`.`a`>(exists(select 1 from `test`.`t2` where (`test`.`t1`.`a` = `test`.`t2`.`a`)))
EXPLAIN EXTENDED
SELECT 2 FROM t1 WHERE EXISTS ((SELECT 1 FROM t2 WHERE t1.a=t2.a) UNION 
(SELECT 1 FROM t2 WHERE t1.a = t2.a));
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'UNION 
(SELECT 1 FROM t2 WHERE t1.a = t2.a))' at line 2
DROP TABLE t1,t2;
create table t1(f11 int, f12 int);
create table t2(f21 int unsigned not null, f22 int, f23 varchar(10));
insert into t1 values(1,1),(2,2), (3, 3);
set session sort_buffer_size= 33*1024;
select count(*) from t1 where f12 = 
(select f22 from t2 where f22 = f12 order by f21 desc, f22, f23 limit 1);
count(*)
3
drop table t1,t2;
End of 5.0 tests.
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES (2,22),(1,11),(2,22);
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 0 GROUP BY a;
a
1
2
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 1 GROUP BY a;
a
SELECT a FROM t1 t0
WHERE (SELECT COUNT(t0.b) FROM t1 t WHERE t.b>20) GROUP BY a;
a
1
2
SET @@sql_mode='ansi';
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 0 GROUP BY a;
ERROR HY000: Invalid use of group function
SELECT a FROM t1 WHERE (SELECT COUNT(b) FROM DUAL) > 1 GROUP BY a;
ERROR HY000: Invalid use of group function
SELECT a FROM t1 t0
WHERE (SELECT COUNT(t0.b) FROM t1 t WHERE t.b>20) GROUP BY a;
ERROR HY000: Invalid use of group function
SET @@sql_mode=default;
DROP TABLE t1;
CREATE TABLE t1 (s1 char(1));
INSERT INTO t1 VALUES ('a');
SELECT * FROM t1 WHERE _utf8'a' = ANY (SELECT s1 FROM t1);
s1
a
DROP TABLE t1;