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|
drop table if exists t1,t2,t3,t4,t5,t6;
CREATE TABLE t1 (a int not null, b char (10) not null);
insert into t1 values(1,'a'),(2,'b'),(3,'c'),(3,'c');
CREATE TABLE t2 (a int not null, b char (10) not null);
insert into t2 values (3,'c'),(4,'d'),(5,'f'),(6,'e');
select a,b from t1 union distinct select a,b from t2;
a b
1 a
2 b
3 c
4 d
5 f
6 e
select a,b from t1 union all select a,b from t2;
a b
1 a
2 b
3 c
3 c
3 c
4 d
5 f
6 e
select a,b from t1 union all select a,b from t2 order by b;
a b
1 a
2 b
3 c
3 c
3 c
4 d
6 e
5 f
select a,b from t1 union all select a,b from t2 union select 7,'g';
a b
1 a
2 b
3 c
3 c
3 c
4 d
5 f
6 e
7 g
select 0,'#' union select a,b from t1 union all select a,b from t2 union select 7,'gg';
0 #
0 #
1 a
2 b
3 c
3 c
3 c
4 d
5 f
6 e
7 g
select a,b from t1 union select a,b from t1;
a b
1 a
2 b
3 c
select 't1',b,count(*) from t1 group by b UNION select 't2',b,count(*) from t2 group by b;
t1 b count(*)
t1 a 1
t1 b 1
t1 c 2
t2 c 1
t2 d 1
t2 e 1
t2 f 1
(select a,b from t1 limit 2) union all (select a,b from t2 order by a) limit 4;
a b
1 a
2 b
3 c
4 d
(select a,b from t1 limit 2) union all (select a,b from t2 order by a limit 1);
a b
1 a
2 b
3 c
(select a,b from t1 limit 2) union all (select a,b from t2 order by a limit 1) order by b desc;
a b
3 c
2 b
1 a
explain (select a,b from t1 limit 2) union all (select a,b from t2 order by a limit 1) order by b desc;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 4
t2 ALL NULL NULL NULL NULL 4 Using filesort
(select sql_calc_found_rows a,b from t1 limit 2) union all (select a,b from t2 order by a) limit 2;
a b
1 a
2 b
select found_rows();
found_rows()
6
select sql_calc_found_rows a,b from t1 union all select a,b from t2 limit 2;
a b
1 a
2 b
select found_rows();
found_rows()
8
explain select a,b from t1 union all select a,b from t2;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 4
t2 ALL NULL NULL NULL NULL 4
explain select xx from t1 union select 1;
Unknown column 'xx' in 'field list'
explain select a,b from t1 union select 1;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 4
0 0 No tables used
explain select 1 union select a,b from t1 union select 1;
table type possible_keys key key_len ref rows Extra
0 0 No tables used
t1 ALL NULL NULL NULL NULL 4
0 0 No tables used
explain select a,b from t1 union select 1 limit 0;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 4
0 0 Impossible WHERE
select a,b from t1 into outfile 'skr' union select a,b from t2;
Wrong usage of UNION and INTO
select a,b from t1 order by a union select a,b from t2;
Wrong usage of UNION and ORDER BY
insert into t3 select a from t1 order by a union select a from t2;
Wrong usage of UNION and ORDER BY
create table t3 select a,b from t1 union select a from t2;
The used SELECT statements have a different number of columns
select a,b from t1 union select a from t2;
The used SELECT statements have a different number of columns
select * from t1 union select a from t2;
The used SELECT statements have a different number of columns
select a from t1 union select * from t2;
The used SELECT statements have a different number of columns
select * from t1 union select SQL_BUFFER_RESULT * from t2;
Wrong usage/placement of 'SQL_BUFFER_RESULT'
create table t3 select a,b from t1 union all select a,b from t2;
insert into t3 select a,b from t1 union all select a,b from t2;
replace into t3 select a,b as c from t1 union all select a,b from t2;
drop table t1,t2,t3;
CREATE TABLE t1 (
`pseudo` char(35) NOT NULL default '',
`pseudo1` char(35) NOT NULL default '',
`same` tinyint(1) unsigned NOT NULL default '1',
PRIMARY KEY (`pseudo1`),
KEY `pseudo` (`pseudo`)
) TYPE=MyISAM;
INSERT INTO t1 (pseudo,pseudo1,same) VALUES ('joce', 'testtt', 1),('joce', 'tsestset', 1),('dekad', 'joce', 1);
SELECT pseudo FROM t1 WHERE pseudo1='joce' UNION SELECT pseudo FROM t1 WHERE pseudo='joce';
pseudo
dekad
joce
SELECT pseudo1 FROM t1 WHERE pseudo1='joce' UNION SELECT pseudo1 FROM t1 WHERE pseudo='joce';
pseudo1
joce
testtt
tsestset
SELECT * FROM t1 WHERE pseudo1='joce' UNION SELECT * FROM t1 WHERE pseudo='joce' order by pseudo desc,pseudo1 desc;
pseudo pseudo1 same
joce tsestset 1
joce testtt 1
dekad joce 1
SELECT pseudo1 FROM t1 WHERE pseudo='joce' UNION SELECT pseudo FROM t1 WHERE pseudo1='joce';
pseudo1
testtt
tsestset
dekad
SELECT pseudo1 FROM t1 WHERE pseudo='joce' UNION ALL SELECT pseudo FROM t1 WHERE pseudo1='joce';
pseudo1
testtt
tsestset
dekad
SELECT pseudo1 FROM t1 WHERE pseudo='joce' UNION SELECT 1;
pseudo1
testtt
tsestset
1
drop table t1;
drop table if exists t1,t2;
create table t1 (a int);
create table t2 (a int);
insert into t1 values (1),(2),(3),(4),(5);
insert into t2 values (11),(12),(13),(14),(15);
(select * from t1 limit 2) union (select * from t2 limit 3) limit 4;
a
1
2
11
12
(select * from t1 limit 2) union (select * from t2 limit 3);
a
1
2
11
12
13
(select * from t1 limit 2) union (select * from t2 limit 20,3);
a
1
2
set SQL_SELECT_LIMIT=2;
(select * from t1 limit 1) union (select * from t2 limit 3);
a
1
11
set SQL_SELECT_LIMIT=DEFAULT;
drop table t1,t2;
CREATE TABLE t1 (
cid smallint(5) unsigned NOT NULL default '0',
cv varchar(250) NOT NULL default '',
PRIMARY KEY (cid),
UNIQUE KEY cv (cv)
) ;
INSERT INTO t1 VALUES (8,'dummy');
CREATE TABLE t2 (
cid bigint(20) unsigned NOT NULL auto_increment,
cap varchar(255) NOT NULL default '',
PRIMARY KEY (cid),
KEY cap (cap)
) ;
CREATE TABLE t3 (
gid bigint(20) unsigned NOT NULL auto_increment,
gn varchar(255) NOT NULL default '',
must tinyint(4) default NULL,
PRIMARY KEY (gid),
KEY gn (gn)
) ;
INSERT INTO t3 VALUES (1,'V1',NULL);
CREATE TABLE t4 (
uid bigint(20) unsigned NOT NULL default '0',
gid bigint(20) unsigned default NULL,
rid bigint(20) unsigned default NULL,
cid bigint(20) unsigned default NULL,
UNIQUE KEY m (uid,gid,rid,cid),
KEY uid (uid),
KEY rid (rid),
KEY cid (cid),
KEY container (gid,rid,cid)
) ;
INSERT INTO t4 VALUES (1,1,NULL,NULL);
CREATE TABLE t5 (
rid bigint(20) unsigned NOT NULL auto_increment,
rl varchar(255) NOT NULL default '',
PRIMARY KEY (rid),
KEY rl (rl)
) ;
CREATE TABLE t6 (
uid bigint(20) unsigned NOT NULL auto_increment,
un varchar(250) NOT NULL default '',
uc smallint(5) unsigned NOT NULL default '0',
PRIMARY KEY (uid),
UNIQUE KEY nc (un,uc),
KEY un (un)
) ;
INSERT INTO t6 VALUES (1,'test',8);
SELECT t4.uid, t5.rl, t3.gn as g1, t4.cid, t4.gid as gg FROM t3, t6, t1, t4 left join t5 on t5.rid = t4.rid left join t2 on t2.cid = t4.cid WHERE t3.gid=t4.gid AND t6.uid = t4.uid AND t6.uc = t1.cid AND t1.cv = "dummy" AND t6.un = "test";
uid rl g1 cid gg
1 NULL V1 NULL 1
SELECT t4.uid, t5.rl, t3.gn as g1, t4.cid, t4.gid as gg FROM t3, t6, t1, t4 left join t5 on t5.rid = t4.rid left join t2 on t2.cid = t4.cid WHERE t3.gid=t4.gid AND t6.uid = t4.uid AND t3.must IS NOT NULL AND t6.uc = t1.cid AND t1.cv = "dummy" AND t6.un = "test";
uid rl g1 cid gg
(SELECT t4.uid, t5.rl, t3.gn as g1, t4.cid, t4.gid as gg FROM t3, t6, t1, t4 left join t5 on t5.rid = t4.rid left join t2 on t2.cid = t4.cid WHERE t3.gid=t4.gid AND t6.uid = t4.uid AND t3.must IS NOT NULL AND t6.uc = t1.cid AND t1.cv = "dummy" AND t6.un = "test") UNION (SELECT t4.uid, t5.rl, t3.gn as g1, t4.cid, t4.gid as gg FROM t3, t6, t1, t4 left join t5 on t5.rid = t4.rid left join t2 on t2.cid = t4.cid WHERE t3.gid=t4.gid AND t6.uid = t4.uid AND t6.uc = t1.cid AND t1.cv = "dummy" AND t6.un = "test");
uid rl g1 cid gg
1 NULL V1 NULL 1
drop table t1,t2,t3,t4,t5,t6;
CREATE TABLE t1 (a int not null, b char (10) not null);
insert into t1 values(1,'a'),(2,'b'),(3,'c'),(3,'c');
CREATE TABLE t2 (a int not null, b char (10) not null);
insert into t2 values (3,'c'),(4,'d'),(5,'f'),(6,'e');
create table t3 select a,b from t1 union select a,b from t2;
create table t4 (select a,b from t1) union (select a,b from t2) limit 2;
insert into t4 select a,b from t1 union select a,b from t2;
insert into t3 (select a,b from t1) union (select a,b from t2) limit 2;
select * from t3;
a b
1 a
2 b
3 c
4 d
5 f
6 e
1 a
2 b
select * from t4;
a b
1 a
2 b
1 a
2 b
3 c
4 d
5 f
6 e
drop table t1,t2,t3,t4;
create table t1 (a int);
insert into t1 values (1),(2),(3);
create table t2 (a int);
insert into t2 values (3),(4),(5);
(SELECT SQL_CALC_FOUND_ROWS * FROM t1) UNION all (SELECT * FROM t2) LIMIT 1;
a
1
select found_rows();
found_rows()
6
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1) UNION all (SELECT * FROM t2) LIMIT 2;
a
1
3
select found_rows();
found_rows()
4
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1) UNION all (SELECT * FROM t2);
a
1
3
4
5
select found_rows();
found_rows()
4
(SELECT SQL_CALC_FOUND_ROWS * FROM t1) UNION all (SELECT * FROM t2 LIMIT 1);
a
1
2
3
3
select found_rows();
found_rows()
4
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1) UNION SELECT * FROM t2 LIMIT 1;
a
1
select found_rows();
found_rows()
4
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1 UNION all SELECT * FROM t2 LIMIT 2;
a
1
3
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION all SELECT * FROM t2 LIMIT 2;
a
1
2
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 2;
a
1
2
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 100;
a
1
2
3
4
5
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 100 UNION SELECT * FROM t2;
a
1
2
3
4
5
select found_rows();
found_rows()
5
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1 UNION SELECT * FROM t2;
a
1
3
4
5
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1 UNION SELECT * FROM t2 LIMIT 2;
a
1
3
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 2,2;
a
3
4
select found_rows();
found_rows()
6
SELECT SQL_CALC_FOUND_ROWS * FROM t1 limit 2,2 UNION SELECT * FROM t2;
a
3
4
5
select found_rows();
found_rows()
5
SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY a desc LIMIT 1;
a
5
(SELECT * FROM t1 ORDER by a) UNION ALL (SELECT * FROM t2 ORDER BY a) ORDER BY A desc LIMIT 4;
a
5
4
3
3
(SELECT * FROM t1) UNION all (SELECT SQL_CALC_FOUND_ROWS * FROM t2) LIMIT 1;
Wrong usage/placement of 'SQL_CALC_FOUND_ROWS'
create temporary table t1 select a from t1 union select a from t2;
drop table t1;
create table t1 select a from t1 union select a from t2;
INSERT TABLE 't1' isn't allowed in FROM table list
select a from t1 union select a from t2 order by t2.a;
Unknown column 't2.a' in 'ORDER BY'
drop table t1,t2;
select length(version()) > 1 as `*` UNION select 2;
*
1
2
create table t1 (a int);
insert into t1 values (0), (3), (1), (2);
explain (select * from t1) union (select * from t1) order by a;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 4
t1 ALL NULL NULL NULL NULL 4
drop table t1;
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