subselect.result

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

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	Extra
1	PRIMARY	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	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
3	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
NULL	UNION RESULT	<union1,3>	ALL	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	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
3	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
4	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1249	Select 2 was reduced during optimization
Note	1003	select (select 0 AS `0` union select 0 AS `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	Extra
1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	
3	DEPENDENT SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
2	DERIVED	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1276	Field or reference '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 ((select `b`.`a` AS `a`) = 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;
a
SELECT (SELECT 1) as a FROM (SELECT 1) b WHERE (SELECT a) IS NOT NULL;
a
1
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	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	Using filesort
3	UNION	t4	ALL	NULL	NULL	NULL	NULL	3	Using where
4	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
NULL	UNION RESULT	<union1,3>	ALL	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` AS `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) AS `max(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
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	Extra
1	PRIMARY	<derived3>	system	NULL	NULL	NULL	NULL	1	
3	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Using filesort
Warnings:
Note	1003	select (select `test`.`t3`.`a` AS `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`
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	Extra
1	PRIMARY	t4	ALL	NULL	NULL	NULL	NULL	3	
2	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
3	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
Warnings:
Note	1276	Field or reference 't4.a' of SELECT #3 was resolved in SELECT #1
Note	1003	select `test`.`t4`.`b` AS `b`,(select avg((`test`.`t2`.`a` + (select min(`test`.`t3`.`a`) AS `min(t3.a)` from `test`.`t3` where (`test`.`t3`.`a` >= `test`.`t4`.`a`)))) AS `avg(t2.a+(select min(t3.a) from t3 where t3.a >= 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	Extra
1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	3	Using where
2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	3	
Warnings:
Note	1003	select `test`.`t3`.`a` AS `a` from `test`.`t3` where <nop>((`test`.`t3`.`a` >= (select min(`test`.`t2`.`b`) from `test`.`t2`)))
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	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	2	
2	DEPENDENT SUBQUERY	t1	system	NULL	NULL	NULL	NULL	1	
3	DEPENDENT UNION	t5	ALL	NULL	NULL	NULL	NULL	2	Using where
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
Warnings: