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
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
4	d
5	f
6	e
7	gg
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
(select a,b from t1 limit 2)  union all (select a,b from t2 order by a limit 1) order by t1.b;
ERROR 42000: Table 't1' from one of the SELECTs cannot be used in ORDER BY
explain extended (select a,b from t1 limit 2)  union all (select a,b from t2 order by a limit 1) order by b desc;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	
2	UNION	t2	ALL	NULL	NULL	NULL	NULL	4	100.00	Using filesort
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	Using filesort
Warnings:
Note	1003	(/* select#1 */ select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` limit 2) union all (/* select#2 */ select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b` from `test`.`t2` order by `test`.`t2`.`a` limit 1) order by `b` desc
select count(*) from (
(select                      a,b from t1 limit 2)  union all (select a,b from t2 order by a)) q;
count(*)
6
(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 count(*) from (
select                      a,b from t1  union all select a,b from t2) q;
count(*)
8
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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
2	UNION	t2	ALL	NULL	NULL	NULL	NULL	4	
explain select xx from t1 union select 1;
ERROR 42S22: Unknown column 'xx' in 'SELECT'
explain select a,b from t1 union select 1;
ERROR 21000: The used SELECT statements have a different number of columns
explain select 1 union select a,b from t1 union select 1;
ERROR 21000: The used SELECT statements have a different number of columns
explain select a,b from t1 union select 1 limit 0;
ERROR 21000: The used SELECT statements have a different number of columns
select a,b from t1 into outfile 'skr' union select a,b from t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'union select a,b from t2' at line 1
select a,b from t1 order by a union select a,b from t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'union select a,b from t2' at line 1
insert into t3 select a from t1 order by a union select a from t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'union select a from t2' at line 1
create table t3 select a,b from t1 union select a from t2;
ERROR 21000: The used SELECT statements have a different number of columns
select a,b from t1 union select a from t2;
ERROR 21000: The used SELECT statements have a different number of columns
select * from t1 union select a from t2;
ERROR 21000: The used SELECT statements have a different number of columns
select a from t1 union select * from t2;
ERROR 21000: The used SELECT statements have a different number of columns
select * from t1 union select SQL_BUFFER_RESULT * from t2;
ERROR 42000: Incorrect 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;
select * union select 1;
ERROR HY000: No tables used
select 1 as a,(select a union select a);
a	(select a union select a)
1	1
(select 1) union (select 2) order by 0;
ERROR 42S22: Unknown column '0' in 'ORDER BY'
SELECT @a:=1 UNION SELECT @a:=@a+1;
@a:=1
1
2
(SELECT 1) UNION (SELECT 2) ORDER BY (SELECT a);
ERROR 42S22: Unknown column 'a' in 'SELECT'
(SELECT 1,3) UNION (SELECT 2,1) ORDER BY (SELECT 2);
1	3
1	3
2	1
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`)
) ENGINE=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;
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)
) ;
Warnings:
Note	1071	Specified key was too long; max key length is 1000 bytes
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)
) ;
Warnings:
Note	1071	Specified key was too long; max key length is 1000 bytes
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)
) ;
Warnings:
Note	1071	Specified key was too long; max key length is 1000 bytes
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 COUNT(*) FROM (
(SELECT                     * FROM t1) UNION all (SELECT * FROM t2)) q;
COUNT(*)
6
(SELECT SQL_CALC_FOUND_ROWS * FROM t1) UNION all (SELECT * FROM t2) LIMIT 1;
a
1
select found_rows();
found_rows()
6
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 1) UNION all (SELECT * FROM t2)) q;
COUNT(*)
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()
4
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 1) UNION all (SELECT * FROM t2)) q;
COUNT(*)
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 COUNT(*) FROM (
(SELECT                     * FROM t1) UNION all (SELECT * FROM t2 LIMIT 1)) q;
COUNT(*)
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 COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 1) UNION SELECT * FROM t2) q;
COUNT(*)
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;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION all SELECT * FROM t2 LIMIT 2' at line 1
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION all SELECT * FROM t2 LIMIT 2;
a
1
2
select found_rows();
found_rows()
6
SELECT COUNT(*) FROM (
SELECT                     * FROM t1 UNION SELECT * FROM t2) q;
COUNT(*)
5
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 2;
a
1
2
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 1) UNION all SELECT * FROM t2) q;
COUNT(*)
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()
4
SELECT COUNT(*) FROM (
SELECT                     * FROM t1 UNION all SELECT * FROM t2) q;
COUNT(*)
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()
5
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 100 UNION SELECT * FROM t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT * FROM t2' at line 1
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 100) UNION SELECT * FROM t2) q;
COUNT(*)
5
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 100) UNION SELECT * FROM t2;
a
1
2
3
4
5
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1 UNION SELECT * FROM t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT * FROM t2' at line 1
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 1) UNION SELECT * FROM t2) q;
COUNT(*)
4
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1) UNION SELECT * FROM t2;
a
1
3
4
5
SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1 UNION SELECT * FROM t2 LIMIT 2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT * FROM t2 LIMIT 2' at line 1
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 LIMIT 1) UNION SELECT * FROM t2) q;
COUNT(*)
4
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 LIMIT 1) UNION SELECT * FROM t2 LIMIT 2;
a
1
3
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 2,2;
a
3
4
select found_rows();
found_rows()
5
SELECT COUNT(*) FROM (
SELECT                     * FROM t1 UNION SELECT * FROM t2) q;
COUNT(*)
5
SELECT SQL_CALC_FOUND_ROWS * FROM t1 limit 2,2 UNION SELECT * FROM t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT * FROM t2' at line 1
SELECT COUNT(*) FROM (
(SELECT                     * FROM t1 limit 2,2) UNION SELECT * FROM t2) q;
COUNT(*)
3
(SELECT SQL_CALC_FOUND_ROWS * FROM t1 limit 2,2) UNION SELECT * FROM t2;
a
3
4
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;
ERROR 42000: Incorrect usage/placement of 'SQL_CALC_FOUND_ROWS'
create temporary table t1 select a from t1 union select a from t2;
drop temporary table t1;
create table t1 select a from t1 union select a from t2;
ERROR 42S01: Table 't1' already exists
select a from t1 union select a from t2 order by t2.a;
ERROR 42000: Table 't2' from one of the SELECTs cannot be used 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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	
2	UNION	t1	ALL	NULL	NULL	NULL	NULL	4	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	Using filesort
drop table t1;
CREATE TABLE t1 (  id int(3) unsigned default '0') ENGINE=MyISAM;
INSERT INTO t1 (id) VALUES("1");
CREATE TABLE t2 ( id int(3) unsigned default '0',  id_master int(5) default '0',  text1 varchar(5) default NULL,  text2 varchar(5) default NULL) ENGINE=MyISAM;
INSERT INTO t2 (id, id_master, text1, text2) VALUES("1", "1",
"foo1", "bar1");
INSERT INTO t2 (id, id_master, text1, text2) VALUES("2", "1",
"foo2", "bar2");
INSERT INTO t2 (id, id_master, text1, text2) VALUES("3", "1", NULL,
"bar3");
INSERT INTO t2 (id, id_master, text1, text2) VALUES("4", "1",
"foo4", "bar4");
SELECT 1 AS id_master, 1 AS id, NULL AS text1, 'ABCDE' AS text2 UNION SELECT id_master, t2.id, text1, text2 FROM t1 LEFT JOIN t2 ON t1.id = t2.id_master;
id_master	id	text1	text2
1	1	NULL	ABCDE
1	1	foo1	bar1
1	2	foo2	bar2
1	3	NULL	bar3
1	4	foo4	bar4
SELECT 1 AS id_master, 1 AS id, 'ABCDE' AS text1, 'ABCDE' AS text2 UNION SELECT id_master, t2.id, text1, text2 FROM t1 LEFT JOIN t2 ON t1.id = t2.id_master;
id_master	id	text1	text2
1	1	ABCDE	ABCDE
1	1	foo1	bar1
1	2	foo2	bar2
1	3	NULL	bar3
1	4	foo4	bar4
drop table if exists t1,t2;
create table t1 (a int not null primary key auto_increment, b int, key(b));
create table t2 (a int not null primary key auto_increment, b int);
insert into t1 (b) values (1),(2),(2),(3);
insert into t2 (b) values (10),(11),(12),(13);
explain extended (select * from t1 where a=1) union (select * from t2 where a=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	100.00	
2	UNION	t2	const	PRIMARY	PRIMARY	4	const	1	100.00	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	(/* select#1 */ select 1 AS `a`,1 AS `b` from `test`.`t1` where 1) union (/* select#2 */ select 1 AS `a`,10 AS `b` from `test`.`t2` where 1)
(select * from t1 where a=5) union (select * from t2 where a=1);
a	b
1	10
(select * from t1 where a=5 and a=6) union (select * from t2 where a=1);
a	b
1	10
(select t1.a,t1.b from t1,t2 where t1.a=5) union (select * from t2 where a=1);
a	b
1	10
(select * from t1 where a=1) union (select t1.a,t2.a from t1,t2 where t1.a=t2.a);
a	b
1	1
2	2
3	3
4	4
set @save_optimizer_use_condition_selectivity=@@optimizer_use_condition_selectivity,@save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='outer_join_with_cache=off',@@optimizer_use_condition_selectivity=4;
explain (select * from t1 where a=1 and b=10) union (select straight_join t1.a,t2.a from t1,t2 where t1.a=t2.a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
2	UNION	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index
2	UNION	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.a	1	Using index
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
set @@optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity,@@optimizer_switch=@save_optimizer_switch;
explain (select * from t1 where a=1) union (select * from t1 where b=1);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	
2	UNION	t1	ref	b	b	5	const	1	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
drop table t1,t2;
create table t1 (   id int not null auto_increment, primary key (id)   ,user_name text );
create table t2 (    id int not null auto_increment, primary key (id)   ,group_name text );
create table t3 (    id int not null auto_increment, primary key (id)   ,user_id int   ,index user_idx (user_id)   ,foreign key (user_id) references users(id)   ,group_id int   ,index group_idx (group_id)   ,foreign key (group_id) references groups(id) );
insert into t1 (user_name) values ('Tester');
insert into t2 (group_name) values ('Group A');
insert into t2 (group_name) values ('Group B');
insert into t3 (user_id, group_id) values (1,1);
select 1 'is_in_group', a.user_name, c.group_name, b.id from t1 a, t3 b, t2 c where a.id = b.user_id and b.group_id = c.id UNION  select 0 'is_in_group', a.user_name, c.group_name, null from t1 a, t2 c;
is_in_group	user_name	group_name	id
1	Tester	Group A	1
0	Tester	Group A	NULL
0	Tester	Group B	NULL
drop table t1, t2, t3;
create table t1 (mat_id MEDIUMINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, matintnum CHAR(6) NOT NULL, test MEDIUMINT UNSIGNED NULL);
create table t2 (mat_id MEDIUMINT UNSIGNED NOT NULL, pla_id MEDIUMINT UNSIGNED NOT NULL);
insert into t1 values (NULL, 'a', 1), (NULL, 'b', 2), (NULL, 'c', 3), (NULL, 'd', 4), (NULL, 'e', 5), (NULL, 'f', 6), (NULL, 'g', 7), (NULL, 'h', 8), (NULL, 'i', 9);
insert into t2 values (1, 100), (1, 101), (1, 102), (2, 100), (2, 103), (2, 104), (3, 101), (3, 102), (3, 105);
SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id union SELECT 0, 0;
pla_id	matintnum
100	a
101	a
102	a
103	b
104	b
105	c
0	0
drop table t1, t2;
create table t1 SELECT "a" as a UNION select "aa" as a;
select * from t1;
a
a
aa
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` varchar(2) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT 12 as a UNION select "aa" as a;
select * from t1;
a
12
aa
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` varchar(2) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT 12 as a UNION select 12.2 as a;
select * from t1;
a
12.0
12.2
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` decimal(3,1) NOT NULL DEFAULT 0.0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t2 (it1 tinyint, it2 tinyint not null, i int not null, ib bigint, f float, d double, y year, da date, dt datetime, sc char(10), sv varchar(10), b blob, tx text);
insert into t2 values (NULL, 1, 3, 4, 1.5, 2.5, 1972, '1972-10-22', '1972-10-22 11:50', 'testc', 'testv', 'tetetetetest', 'teeeeeeeeeeeest');
create table t1 SELECT it2 from t2 UNION select it1 from t2;
select * from t1;
it2
1
NULL
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `it2` tinyint(4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT it2 from t2 UNION select i from t2;
select * from t1;
it2
1
3
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `it2` int(11) NOT NULL DEFAULT 0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT i from t2 UNION select f from t2;
select * from t1;
i
3
1.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `i` double DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT f from t2 UNION select d from t2;
select * from t1;
f
1.5
2.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `f` double DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT ib from t2 UNION select f from t2;
select * from t1;
ib
4
1.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `ib` double DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT ib from t2 UNION select d from t2;
select * from t1;
ib
4
2.5
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `ib` double DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT f from t2 UNION select y from t2;
select * from t1;
f
1.5
1972
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `f` float DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT f from t2 UNION select da from t2;
select * from t1;
f
1.5
1972-10-22
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `f` varchar(12) CHARACTER SET latin1 COLLATE latin1_swedish_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT y from t2 UNION select da from t2;
select * from t1;
y
1972
1972-10-22
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `y` varchar(10) CHARACTER SET latin1 COLLATE latin1_swedish_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT y from t2 UNION select dt from t2;
select * from t1;
y
1972
1972-10-22 11:50:00
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `y` varchar(19) CHARACTER SET latin1 COLLATE latin1_swedish_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT da from t2 UNION select dt from t2;
select * from t1;
da
1972-10-22 00:00:00
1972-10-22 11:50:00
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `da` datetime DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT dt from t2 UNION select trim(sc) from t2;
select trim(dt) from t1;
trim(dt)
1972-10-22 11:50:00
testc
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `dt` varchar(19) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT dt from t2 UNION select sv from t2;
select * from t1;
dt
1972-10-22 11:50:00
testv
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `dt` varchar(19) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT sc from t2 UNION select sv from t2;
select * from t1;
sc
testc
testv
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `sc` varchar(10) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT dt from t2 UNION select b from t2;
select * from t1;
dt
1972-10-22 11:50:00
tetetetetest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `dt` blob DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT sv from t2 UNION select b from t2;
select * from t1;
sv
testv
tetetetetest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `sv` blob DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT i from t2 UNION select d from t2 UNION select b from t2;
select * from t1;
i
3
2.5
tetetetetest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `i` blob DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT sv from t2 UNION select tx from t2;
select * from t1;
sv
testv
teeeeeeeeeeeest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `sv` mediumtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 SELECT b from t2 UNION select tx from t2;
select * from t1;
b
tetetetetest
teeeeeeeeeeeest
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `b` blob DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1,t2;
create table t1 select 1 union select -1;
select * from t1;
1
1
-1
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `1` int(2) NOT NULL DEFAULT 0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 select _latin1"test" union select _latin2"testt" ;
ERROR HY000: Illegal mix of collations (latin1_swedish_ci,COERCIBLE) and (latin2_general_ci,COERCIBLE) for operation 'UNION'
create table t1 select _latin2"test" union select _latin2"testt" ;
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `test` varchar(5) CHARACTER SET latin2 COLLATE latin2_general_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 (s char(200));
insert into t1 values (repeat("1",200));
create table t2 select * from t1;
insert into t2 select * from t1;
insert into t1 select * from t2;
insert into t2 select * from t1;
insert into t1 select * from t2;
insert into t2 select * from t1;
set local tmp_table_size=16384;
select count(*) from (select * from t1 union all select * from t2 order by 1) b;
count(*)
21
select count(*) from t1;
count(*)
8
select count(*) from t2;
count(*)
13
drop table t1,t2;
set local tmp_table_size=default;
create table t1 (a int, index (a), b int);
insert t1 values (1,1),(2,2),(3,3),(4,4),(5,5);
insert t1 select a+1, a+b from t1;
insert t1 select a+1, a+b from t1;
insert t1 select a+1, a+b from t1;
insert t1 select a+1, a+b from t1;
insert t1 select a+1, a+b from t1;
FLUSH STATUS;
show status like 'Slow_queries';
Variable_name	Value
Slow_queries	0
select count(*) from t1 where a=7;
count(*)
26
show status like 'Slow_queries';
Variable_name	Value
Slow_queries	0
select count(*) from t1 where b=13;
count(*)
10
show status like 'Slow_queries';
Variable_name	Value
Slow_queries	1
select count(*) from t1 where b=13 union select count(*) from t1 where a=7;
count(*)
10
26
show status like 'Slow_queries';
Variable_name	Value
Slow_queries	2
select count(*) from t1 where a=7 union select count(*) from t1 where b=13;
count(*)
26
10
show status like 'Slow_queries';
Variable_name	Value
Slow_queries	3
flush status;
select a from t1 where b not in (1,2,3) union select a from t1 where b not in (4,5,6);
a
4
5
3
6
7
8
9
10
1
2
show status like 'Slow_queries';
Variable_name	Value
Slow_queries	1
drop table t1;
create table t1 (   RID int(11) not null default '0',   IID int(11) not null default '0',    nada varchar(50)  not null,NAME varchar(50) not null,PHONE varchar(50) not null) engine=MyISAM;
insert into t1 ( RID,IID,nada,NAME,PHONE) values (1, 1, 'main', 'a', '111'), (2, 1, 'main', 'b', '222'), (3, 1, 'main', 'c', '333'), (4, 1, 'main', 'd', '444'), (5, 1, 'main', 'e', '555'), (6, 2, 'main', 'c', '333'), (7, 2, 'main', 'd', '454'), (8, 2, 'main', 'e', '555'), (9, 2, 'main', 'f', '666'), (10, 2, 'main', 'g', '777');
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='outer_join_with_cache=off';
select A.NAME, A.PHONE, B.NAME, B.PHONE from t1 A left join t1 B on A.NAME = B.NAME and B.IID = 2 where A.IID = 1 and (A.PHONE <> B.PHONE or B.NAME is null) union select A.NAME, A.PHONE, B.NAME, B.PHONE from t1 B left join t1 A on B.NAME = A.NAME and A.IID = 1 where B.IID = 2 and (A.PHONE <> B.PHONE or A.NAME is null);
NAME	PHONE	NAME	PHONE
a	111	NULL	NULL
b	222	NULL	NULL
d	444	d	454
NULL	NULL	f	666
NULL	NULL	g	777
SET optimizer_switch=@save_optimizer_switch;
drop  table t1;
create table t1 (col1 tinyint unsigned, col2 tinyint unsigned);
insert into t1 values (1,2),(3,4),(5,6),(7,8),(9,10);
select col1 n from t1 union select col2 n from t1 order by n;
n
1
2
3
4
5
6
7
8
9
10
alter table t1 add index myindex (col2);
select col1 n from t1 union select col2 n from t1 order by n;
n
1
2
3
4
5
6
7
8
9
10
drop  table t1;
create table t1 (i int);
insert into t1 values (1);
select * from t1 UNION select * from t1;
i
1
select * from t1 UNION ALL select * from t1;
i
1
1
select * from t1 UNION select * from t1 UNION ALL select * from t1;
i
1
1
drop table t1;
select 1 as a union all select 1 union all select 2 union select 1 union all select 2;
a
1
2
2
set sql_select_limit=1;
select 1 union select 2;
1
1
(select 1) union (select 2);
1
1
(select 1) union (select 2) union (select 3) limit 2;
1
1
2
set sql_select_limit=default;
create table t1 (a int);
insert into t1 values (100), (1);
create table t2 (a int);
insert into t2 values (100);
select a from t1 union select a from t2 order by a;
a
1
100
SET SQL_SELECT_LIMIT=1;
select a from t1 union select a from t2 order by a;
a
1
drop table t1, t2;
set sql_select_limit=default;
CREATE TABLE t1 (i int(11) default NULL,c char(1) default NULL,KEY i (i));
CREATE TABLE t2 (i int(11) default NULL,c char(1) default NULL,KEY i (i));
explain (select * from t1) union (select * from t2) order by not_existing_column;
ERROR 42S22: Unknown column 'not_existing_column' in 'ORDER BY'
drop table t1, t2;
CREATE TABLE t1 (uid int(1));
INSERT INTO t1 SELECT 150;
SELECT 'a' UNION SELECT uid FROM t1;
a
a
150
drop table t1;
CREATE TABLE t1 ( ID1 int(10) unsigned NOT NULL DEFAULT '0' , ID2 datetime NOT NULL DEFAULT '0000-00-00 00:00:00' , DATA1 varchar(10) , DATA2 double(5,4) , DATA3 datetime , PRIMARY KEY (ID1,ID2));
CREATE TABLE t2 ( ID int(3) unsigned NOT NULL DEFAULT '0' , DATA1 timestamp DEFAULT '0000-00-00 00:00:00' , PRIMARY KEY (ID));
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1) UNION
(SELECT * FROM t1 AS PARTITIONED, t2 AS
PARTITIONED_B WHERE PARTITIONED_B.ID=PARTITIONED.ID1);
ID1	ID2	DATA1	DATA2	DATA3	ID	DATA1
drop table t1,t2;
create table t1 (a ENUM('Yes', 'No') NOT NULL);
create table t2 (a ENUM('aaa', 'bbb') NOT NULL);
insert into t1 values ('No');
insert into t2 values ('bbb');
create table t3 (a SET('Yes', 'No') NOT NULL);
create table t4 (a SET('aaa', 'bbb') NOT NULL);
insert into t3 values (1);
insert into t4 values (3);
select "1" as a union select a from t1;
a
1
No
select a as a from t1 union select "1";
a
No
1
select a as a from t2 union select a from t1;
a
bbb
No
select "1" as a union select a from t3;
a
1
Yes
select a as a from t3 union select "1";
a
Yes
1
select a as a from t4 union select a from t3;
a
aaa,bbb
Yes
select a as a from t1 union select a from t4;
a
No
aaa,bbb
drop table t1,t2,t3,t4;
create table t1 as
(select _latin1'test') union
(select _latin1'TEST') union
(select _latin1'TeST');
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `test` varchar(4) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
select count(*) from t1;
count(*)
1
drop table t1;
create table t1 as
(select _latin1'test' collate latin1_bin) union
(select _latin1'TEST') union
(select _latin1'TeST');
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `_latin1'test' collate latin1_bin` varchar(4) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
select count(*) from t1;
count(*)
3
drop table t1;
create table t1 as
(select _latin1'test') union
(select _latin1'TEST' collate latin1_bin) union
(select _latin1'TeST');
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `test` varchar(4) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
select count(*) from t1;
count(*)
3
drop table t1;
create table t1 as
(select _latin1'test') union
(select _latin1'TEST') union
(select _latin1'TeST' collate latin1_bin);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `test` varchar(4) CHARACTER SET latin1 COLLATE latin1_bin DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
select count(*) from t1;
count(*)
3
drop table t1;
create table t2 (
a char character set latin1 collate latin1_swedish_ci,
b char character set latin1 collate latin1_german1_ci);
create table t1 as
(select a from t2) union
(select b from t2);
ERROR HY000: Illegal mix of collations for operation 'UNION'
create table t1 as
(select a collate latin1_german1_ci from t2) union
(select b from t2);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a collate latin1_german1_ci` varchar(1) CHARACTER SET latin1 COLLATE latin1_german1_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 as
(select a from t2) union
(select b collate latin1_german1_ci from t2);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` varchar(1) CHARACTER SET latin1 COLLATE latin1_german1_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
create table t1 as
(select a from t2) union
(select b from t2) union
(select 'c' collate latin1_german1_ci from t2);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` varchar(1) CHARACTER SET latin1 COLLATE latin1_german1_ci DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1;
drop table t2;
create table t1(a1 int, f1 char(10));
create table t2
select f2,a1 from (select a1, CAST('2004-12-31' AS DATE) f2 from t1) a
union
select f2,a1 from (select a1, CAST('2004-12-31' AS DATE) f2 from t1) a
order by f2, a1;
show columns from t2;
Field	Type	Null	Key	Default	Extra
f2	date	YES		NULL	
a1	int(11)	YES		NULL	
drop table t1, t2;
create table t1 (f1 int);
create table t2 (f1 int, f2 int ,f3 date);
create table t3 (f1 int, f2 char(10));
create table t4
(
select t2.f3 as sdate
from t1
left outer join t2 on (t1.f1 = t2.f1)
inner join t3 on (t2.f2 = t3.f1)
order by t1.f1, t3.f1, t2.f3
)
union
(
select cast('2004-12-31' as date) as sdate
from t1
left outer join t2 on (t1.f1 = t2.f1)
inner join t3 on (t2.f2 = t3.f1)
group by t1.f1
order by t1.f1, t3.f1, t2.f3
)
order by sdate;
show columns from t4;
Field	Type	Null	Key	Default	Extra
sdate	date	YES		NULL	
drop table t1, t2, t3, t4;
create table t1 (a int not null, b char (10) not null);
insert into t1 values(1,'a'),(2,'b'),(3,'c'),(3,'c');
select * from ((select * from t1 limit 1)) a;
a	b
1	a
select * from ((select * from t1 limit 1) union (select * from t1 limit 1)) a;
a	b
1	a
select * from ((select * from t1 limit 1) union (select * from t1 limit 1) union (select * from t1 limit 1)) a;
a	b
1	a
select * from ((((select * from t1))) union (select * from t1) union (select * from t1)) a;
a	b
1	a
2	b
3	c
select * from ((select * from t1) union (((select * from t1))) union (select * from t1)) a;
a	b
1	a
2	b
3	c
drop table t1;
set @val:=6;
select concat('value is: ', @val) union select 'some text';
concat('value is: ', @val)
value is: 6
some text
select concat(_latin1'a', _ascii'b' collate ascii_bin);
concat(_latin1'a', _ascii'b' collate ascii_bin)
ab
create table t1 (foo varchar(100)) collate ascii_bin;
insert into t1 (foo) values ("foo");
select foo from t1 union select 'bar' as foo from dual;
foo
foo
bar
drop table t1;
CREATE TABLE t1 (
a ENUM('ä','ö','ü') character set utf8 not null default 'ü',
b ENUM("one", "two") character set utf8,
c ENUM("one", "two")
);
show create table t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` enum('ä','ö','ü') CHARACTER SET utf8mb3 COLLATE utf8mb3_uca1400_ai_ci NOT NULL DEFAULT 'ü',
  `b` enum('one','two') CHARACTER SET utf8mb3 COLLATE utf8mb3_uca1400_ai_ci DEFAULT NULL,
  `c` enum('one','two') DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
insert into t1 values ('ä', 'one', 'one'), ('ö', 'two', 'one'), ('ü', NULL, NULL);
create table t2 select NULL union select a from t1;
show columns from t2;
Field	Type	Null	Key	Default	Extra
NULL	enum('ä','ö','ü')	YES		NULL	
drop table t2;
create table t2 select a from t1 union select NULL;
show columns from t2;
Field	Type	Null	Key	Default	Extra
a	enum('ä','ö','ü')	YES		NULL	
drop table t2;
create table t2 select a from t1 union select a from t1;
show columns from t2;
Field	Type	Null	Key	Default	Extra
a	varchar(2)	NO			
drop table t2;
create table t2 select a from t1 union select c from t1;
drop table t2;
create table t2 select a from t1 union select b from t1;
show columns from t2;
Field	Type	Null	Key	Default	Extra
a	varchar(3)	YES		NULL	
drop table t2, t1;
create table t1 (f1 decimal(60,25), f2 decimal(60,25));
insert into t1 values (0.0,0.0);
select f1 from t1 union all select f2 from t1;
f1
0.0000000000000000000000000
0.0000000000000000000000000
select 'XXXXXXXXXXXXXXXXXXXX' as description, f1 from t1
union all
select 'YYYYYYYYYYYYYYYYYYYY' as description, f2 from t1;
description	f1
XXXXXXXXXXXXXXXXXXXX	0.0000000000000000000000000
YYYYYYYYYYYYYYYYYYYY	0.0000000000000000000000000
drop table t1;
create table t1 (f1 decimal(60,24), f2 decimal(60,24));
insert into t1 values (0.0,0.0);
select f1 from t1 union all select f2 from t1;
f1
0.000000000000000000000000
0.000000000000000000000000
select 'XXXXXXXXXXXXXXXXXXXX' as description, f1 from t1
union all
select 'YYYYYYYYYYYYYYYYYYYY' as description, f2 from t1;
description	f1
XXXXXXXXXXXXXXXXXXXX	0.000000000000000000000000
YYYYYYYYYYYYYYYYYYYY	0.000000000000000000000000
drop table t1;
create table t1 (a varchar(5));
create table t2 select * from t1 union select 'abcdefghijkl';
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(12) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
select row_format from information_schema.TABLES where table_schema="test" and table_name="t2";
row_format
Dynamic
alter table t2 ROW_FORMAT=fixed;
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(12) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci ROW_FORMAT=FIXED
drop table t1,t2;
CREATE TABLE t1 (a mediumtext);
CREATE TABLE t2 (b varchar(20));
INSERT INTO t1 VALUES ('a'),('b');
SELECT left(a,100000000) FROM t1 UNION  SELECT b FROM t2;
left(a,100000000)
a
b
create table t3 SELECT left(a,100000000) FROM t1 UNION  SELECT b FROM t2;
show create table t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `left(a,100000000)` longtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop tables t1,t2,t3;
CREATE TABLE t1 (a longtext);
CREATE TABLE t2 (b varchar(20));
INSERT INTO t1 VALUES ('a'),('b');
SELECT left(a,100000000) FROM t1 UNION  SELECT b FROM t2;
left(a,100000000)
a
b
create table t3 SELECT left(a,100000000) FROM t1 UNION  SELECT b FROM t2;
show create table t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `left(a,100000000)` longtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop tables t1,t2,t3;
SET @tmp_max= @@global.max_allowed_packet;
SET @@global.max_allowed_packet=25000000;
Warnings:
Warning	1292	Truncated incorrect max_allowed_packet value: '25000000'
connect  newconn, localhost, root,,;
CREATE TABLE t1 (a mediumtext);
CREATE TABLE t2 (b varchar(20));
INSERT INTO t1 VALUES ('a');
CREATE TABLE t3 SELECT REPEAT(a,20000000) AS a FROM t1 UNION SELECT b FROM t2;
SHOW CREATE TABLE t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `a` longtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLES t1,t3;
CREATE TABLE t1 (a tinytext);
INSERT INTO t1 VALUES ('a');
CREATE TABLE t3 SELECT REPEAT(a,2) AS a FROM t1 UNION SELECT b FROM t2;
SHOW CREATE TABLE t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `a` varchar(510) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLES t1,t3;
CREATE TABLE t1 (a mediumtext);
INSERT INTO t1 VALUES ('a');
CREATE TABLE t3 SELECT REPEAT(a,2) AS a FROM t1 UNION SELECT b FROM t2;
SHOW CREATE TABLE t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `a` longtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLES t1,t3;
CREATE TABLE t1 (a tinyblob);
INSERT INTO t1 VALUES ('a');
CREATE TABLE t3 SELECT REPEAT(a,2) AS a FROM t1 UNION SELECT b FROM t2;
SHOW CREATE TABLE t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `a` varbinary(510) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLES t1,t2,t3;
connection default;
SET @@global.max_allowed_packet:= @tmp_max;
disconnect newconn;
create table t1 ( id int not null auto_increment, primary key (id), col1 int);
insert into t1 (col1) values (2),(3),(4),(5),(6);
select 99 union all select id from t1 order by 1;
99
1
2
3
4
5
99
select id from t1 union all select 99 order by 1;
id
1
2
3
4
5
99
drop table t1;
create table t1(f1 char(1), f2 char(5), f3 binary(1), f4 binary(5), f5 timestamp NOT NULL DEFAULT '0000-00-00 00:00:00', f6 varchar(1) character set utf8 collate utf8_general_ci, f7 text);
create table t2 as select *, f6 as f8 from t1 union select *, f7 from t1;
show create table t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `f1` char(1) DEFAULT NULL,
  `f2` char(5) DEFAULT NULL,
  `f3` binary(1) DEFAULT NULL,
  `f4` binary(5) DEFAULT NULL,
  `f5` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `f6` varchar(1) CHARACTER SET utf8mb3 COLLATE utf8mb3_general_ci DEFAULT NULL,
  `f7` mediumtext DEFAULT NULL,
  `f8` mediumtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t1, t2;
CREATE TABLE t1
(
c_varchar varchar(1) character set utf8 collate utf8_general_ci,
c_tinytext tinytext,
c_text text,
c_mediumtext mediumtext,
c_longtext longtext
);
CREATE TABLE t2 AS
SELECT c_tinytext, c_text, c_mediumtext, c_longtext FROM t1
UNION
SELECT c_varchar, c_varchar, c_varchar, c_varchar FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `c_tinytext` text DEFAULT NULL,
  `c_text` mediumtext DEFAULT NULL,
  `c_mediumtext` longtext DEFAULT NULL,
  `c_longtext` longtext DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
DROP TABLE t1;
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1)) union
(select avg(1)) union (select avg(1)) union (select avg(1));
avg(1)
1.0000
select _utf8'12' union select _latin1'12345';
12
12
12345
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (3),(1),(2),(4),(1);
SELECT a FROM (SELECT a FROM t1 UNION SELECT a FROM t1 ORDER BY a) AS test;
a
1
2
3
4
SELECT a FROM (SELECT a FROM t1 UNION SELECT a FROM t1 ORDER BY c) AS test;
ERROR 42S22: Unknown column 'c' in 'ORDER BY'
DROP TABLE t1;
(select 1 into @var) union (select 1);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'into @var) union (select 1)' at line 1
(select 1) union (select 1 into @var);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'into @var)' at line 1
select @var;
@var
NULL
(select 2) union (select 1 into @var);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'into @var)' at line 1
(select 1) union (select 1) into @var;
(select 2) union (select 1) into @var;
ERROR 42000: Result consisted of more than one row
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (10), (20);
CREATE TABLE t2 (b int);
INSERT INTO t2 VALUES (10), (50), (50);
SELECT a,1 FROM t1 
UNION
SELECT b, COUNT(*) FROM t2 GROUP BY b WITH ROLLUP
ORDER BY a;
a	1
NULL	3
10	1
20	1
50	2
SELECT a,1 FROM t1 
UNION
SELECT b, COUNT(*) FROM t2 GROUP BY b WITH ROLLUP
ORDER BY a DESC;
a	1
50	2
20	1
10	1
NULL	3
SELECT a,1 FROM t1 
UNION
SELECT b, COUNT(*) FROM t2 GROUP BY b WITH ROLLUP
ORDER BY a ASC LIMIT 3;
a	1
NULL	3
10	1
20	1
SELECT a,1 FROM t1 
UNION ALL 
SELECT b, COUNT(*) FROM t2 GROUP BY b WITH ROLLUP
ORDER BY a DESC;
a	1
50	2
20	1
10	1
10	1
NULL	3
SELECT a,1 FROM t1
UNION 
(SELECT b, COUNT(*) FROM t2 GROUP BY b WITH ROLLUP ORDER BY a);
ERROR HY000: Incorrect usage of CUBE/ROLLUP and ORDER BY
SELECT a,1 FROM t1
UNION ALL
SELECT b, COUNT(*) FROM t2 GROUP BY b WITH ROLLUP ORDER BY a
UNION
SELECT 1,1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION
SELECT 1,1' at line 4
DROP TABLE t1,t2;
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1), (2), (3);
CREATE TABLE t2 SELECT * FROM (SELECT NULL) a UNION SELECT a FROM t1;
DESC t2;
Field	Type	Null	Key	Default	Extra
NULL	int(11)	YES		NULL	
CREATE TABLE t3 SELECT a FROM t1 UNION SELECT * FROM (SELECT NULL) a;
DESC t3;
Field	Type	Null	Key	Default	Extra
a	int(11)	YES		NULL	
CREATE TABLE t4 SELECT NULL;
DESC t4;
Field	Type	Null	Key	Default	Extra
NULL	binary(0)	YES		NULL	
CREATE TABLE t5 SELECT NULL UNION SELECT NULL;
DESC t5;
Field	Type	Null	Key	Default	Extra
NULL	binary(0)	YES		NULL	
CREATE TABLE t6 
SELECT * FROM (SELECT * FROM (SELECT NULL)a) b UNION SELECT a FROM t1;
DESC t6;
Field	Type	Null	Key	Default	Extra
NULL	int(11)	YES		NULL	
DROP TABLE t1, t2, t3, t4, t5, t6;
CREATE TABLE t1 (f FLOAT(9,6));
CREATE TABLE t2 AS SELECT f FROM t1 UNION SELECT f FROM t1;
SHOW FIELDS FROM t2;
Field	Type	Null	Key	Default	Extra
f	float(9,6)	YES		NULL	
DROP TABLE t1, t2;
CREATE TABLE t1(d DOUBLE(9,6));
CREATE TABLE t2 AS SELECT d FROM t1 UNION SELECT d FROM t1;
SHOW FIELDS FROM t2;
Field	Type	Null	Key	Default	Extra
d	double(9,6)	YES		NULL	
DROP TABLE t1, t2;
CREATE TABLE t1(a INT);
EXPLAIN EXTENDED
SELECT a FROM t1
UNION
SELECT a FROM t1
ORDER BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t1	system	NULL	NULL	NULL	NULL	0	0.00	Const row not found
2	UNION	t1	system	NULL	NULL	NULL	NULL	0	0.00	Const row not found
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	Using filesort
Warnings:
Note	1003	/* select#1 */ select NULL AS `a` from `test`.`t1` union /* select#2 */ select NULL AS `a` from `test`.`t1` order by `a`
DROP TABLE t1;
#
# Bug#32858: Error: "Incorrect usage of UNION and INTO" does not take 
# subselects into account
#
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1);
# Tests fix in parser rule select_derived_union.
SELECT a INTO @v FROM (
SELECT a FROM t1
UNION
SELECT a FROM t1
) alias;
SELECT a INTO OUTFILE 'union.out.file' FROM (
SELECT a FROM t1
UNION
SELECT a FROM t1 WHERE 0
) alias;
SELECT a INTO DUMPFILE 'union.out.file2' FROM (
SELECT a FROM t1
UNION
SELECT a FROM t1 WHERE 0
) alias;
SELECT a FROM t1 UNION SELECT a INTO @v FROM t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'FROM t1' at line 1
SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file5' FROM t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'FROM t1' at line 1
SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file6' FROM t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'FROM t1' at line 1
SELECT a FROM t1 UNION SELECT a FROM t1 INTO @v ;
SELECT a FROM t1 UNION SELECT a FROM t1 INTO OUTFILE 'union.out.file5';
SELECT a FROM t1 UNION SELECT a FROM t1 INTO OUTFILE 'union.out.file6';
SELECT a INTO @v FROM t1 UNION SELECT a FROM t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT a FROM t1' at line 1
SELECT a INTO OUTFILE 'union.out.file7' FROM t1 UNION SELECT a FROM t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT a FROM t1' at line 1
SELECT a INTO DUMPFILE 'union.out.file8' FROM t1 UNION SELECT a FROM t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'UNION SELECT a FROM t1' at line 1
# Tests fix in parser rule query_expression_body.
SELECT ( SELECT a UNION SELECT a ) INTO @v FROM t1;
SELECT ( SELECT a UNION SELECT a ) INTO OUTFILE  'union.out.file3' FROM t1;
SELECT ( SELECT a UNION SELECT a ) INTO DUMPFILE 'union.out.file4' FROM t1;
DROP TABLE t1;
# 
# Bug #49734: Crash on EXPLAIN EXTENDED UNION ... ORDER BY 
#   <any non-const-function>
# 
CREATE TABLE t1 (a VARCHAR(10), FULLTEXT KEY a (a));
INSERT INTO t1 VALUES (1),(2);
CREATE TABLE t2 (b INT);
INSERT INTO t2 VALUES (1),(2);
# Should not crash
EXPLAIN EXTENDED
SELECT * FROM t1 UNION SELECT * FROM t1 ORDER BY a + 12;
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	
2	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	Using filesort
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` union /* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` order by `a` + 12
# Should not crash
SELECT * FROM t1 UNION SELECT * FROM t1 ORDER BY a + 12;
a
1
2
# Should not crash
EXPLAIN EXTENDED
SELECT * FROM t1 UNION SELECT * FROM t1
ORDER BY MATCH(a) AGAINST ('+abc' IN BOOLEAN MODE);
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	
2	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	Using filesort
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` union /* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` order by (match `a` against ('+abc' in boolean mode))
# Should not crash
SELECT * FROM t1 UNION SELECT * FROM t1
ORDER BY MATCH(a) AGAINST ('+abc' IN BOOLEAN MODE);
a
1
2
# Should not crash
(SELECT * FROM t1) UNION (SELECT * FROM t1)
ORDER BY MATCH(a) AGAINST ('+abc' IN BOOLEAN MODE);
a
1
2
# Should not crash
EXPLAIN EXTENDED
SELECT * FROM t1 UNION SELECT * FROM t1
ORDER BY (SELECT a FROM t2 WHERE b = 12);
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	
2	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	Using filesort
3	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
Warnings:
Note	1276	Field or reference 'a' of SELECT #3 was resolved in SELECT #-1
Note	1003	/* select#1 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` union /* select#2 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` order by <expr_cache><`a`>((/* select#3 */ select `a` from `test`.`t2` where `test`.`t2`.`b` = 12))
# Should not crash
SELECT * FROM t1 UNION SELECT * FROM t1
ORDER BY (SELECT a FROM t2 WHERE b = 12);
# Should not crash
SELECT * FROM t2 UNION SELECT * FROM t2
ORDER BY (SELECT * FROM t1 WHERE MATCH(a) AGAINST ('+abc' IN BOOLEAN MODE));
b
1
2
DROP TABLE t1,t2;
create table t1 (a int);
insert into t1 values (10),(10),(10),(2),(3),(4),(5),(6),(7),(8),(9),(1),(10);
select a from t1 where false UNION select a from t1 limit 8;
a
10
2
3
4
5
6
7
8
(select a from t1 where false) UNION (select a from t1) limit 8;
a
10
2
3
4
5
6
7
8
drop table t1;
#
# Bug#11765255 58201:
# VALGRIND/CRASH WHEN ORDERING BY MULTIPLE AGGREGATE FUNCTIONS
#
select 1 as foo
union
select 2
union
select 3
union
select 4
order by max(42) + max(1) + max(1) + max(1) + max(1) + max(1)
;
ERROR HY000: Expression #1 of ORDER BY contains aggregate function and applies to a UNION
prepare stmt1 from 'select 1 as foo
union
select 2
union
select 3
union
select 4
order by max(42) + max(1) + max(1) + max(1) + max(1) + max(1)
';
ERROR HY000: Expression #1 of ORDER BY contains aggregate function and applies to a UNION
select 1 as foo
union
select 2
union
select 3
union
(select 4)
order by max(42) + max(1) + max(1) + max(1) + max(1) + max(1)
;
ERROR HY000: Expression #1 of ORDER BY contains aggregate function and applies to a UNION
prepare stmt1 from 'select 1 as foo
union
select 2
union
select 3
union
(select 4)
order by max(42) + max(1) + max(1) + max(1) + max(1) + max(1)
';
ERROR HY000: Expression #1 of ORDER BY contains aggregate function and applies to a UNION
End of 5.1 tests
#
# mdev-5091: Asseirtion failure for UNION with ORDER BY 
#            in one of selects
#
CREATE TABLE t1 (i int, c char(1)) ENGINE=MyISAM;
INSERT INTO t1 VALUES (6,'b');
CREATE VIEW v1 AS SELECT * FROM t1;
( SELECT i FROM v1 GROUP BY i ORDER BY CONCAT( c, c ) LIMIT 1 )
UNION 
( SELECT i FROM t1 );
i
6
DROP VIEW v1;
DROP TABLE t1;
#
# mdev-5382:  UNION with ORDER BY in subselect
#
CREATE TABLE t1 (a int DEFAULT NULL);
INSERT INTO t1 VALUES (2), (4);
CREATE TABLE t2 (b int DEFAULT NULL);
INSERT INTO t2 VALUES (1), (3);
SELECT c1 FROM (SELECT (SELECT a FROM t1 WHERE t1.a <= t2.b
UNION ALL
SELECT a FROM t1 WHERE t1.a+3<= t2.b
ORDER BY a DESC) AS c1 FROM t2) t3;
c1
NULL
2
DROP TABLE t1,t2;
End of 5.3 tests
#
# Bug#57986 ORDER BY clause is not used after a UNION, 
#           if embedded in a SELECT
#
CREATE TABLE t1 (c1 VARCHAR(10) NOT NULL, c2 INT NOT NULL);
CREATE TABLE t2 (c1 VARCHAR(10) NOT NULL, c2 INT NOT NULL);
INSERT INTO t1 (c1, c2) VALUES ('t1a', 1), ('t1a', 2), ('t1a', 3), ('t1b', 2), ('t1b', 1);
INSERT INTO t2 (c1, c2) VALUES ('t2a', 1), ('t2a', 2), ('t2a', 3), ('t2b', 2), ('t2b', 1);
SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY c2, c1;
c1	c2
t1a	1
t1b	1
t2a	1
t2b	1
t1a	2
t1b	2
t2a	2
t2b	2
t1a	3
t2a	3
SELECT * FROM t1 UNION (SELECT * FROM t2) ORDER BY c2, c1;
c1	c2
t1a	1
t1b	1
t2a	1
t2b	1
t1a	2
t1b	2
t2a	2
t2b	2
t1a	3
t2a	3
SELECT * FROM t1 UNION (SELECT * FROM t2 ORDER BY c2, c1);
c1	c2
t1a	1
t1a	2
t1a	3
t1b	2
t1b	1
t2a	1
t2a	2
t2a	3
t2b	2
t2b	1
SELECT c1, c2 FROM (
SELECT c1, c2 FROM t1
UNION
(SELECT c1, c2 FROM t2)
ORDER BY c2, c1
) AS res;
c1	c2
t1a	1
t1b	1
t2a	1
t2b	1
t1a	2
t1b	2
t2a	2
t2b	2
t1a	3
t2a	3
SELECT c1, c2 FROM (
SELECT c1, c2 FROM t1
UNION
(SELECT c1, c2 FROM t2)
ORDER BY c2 DESC, c1 LIMIT 1
) AS res;
c1	c2
t1a	3
SELECT c1, c2 FROM (
SELECT c1, c2 FROM t1
UNION
(SELECT c1, c2 FROM t2 ORDER BY c2 DESC, c1 LIMIT 1)
) AS res;
c1	c2
t1a	1
t1a	2
t1a	3
t1b	2
t1b	1
t2a	3
SELECT c1, c2 FROM (
SELECT c1, c2 FROM t1
UNION
SELECT c1, c2 FROM t2 
ORDER BY c2 DESC, c1 DESC LIMIT 1
) AS res;
c1	c2
t2a	3
SELECT c1, c2 FROM (
(
(SELECT c1, c2 FROM t1)
UNION
(SELECT c1, c2 FROM t2)
)
ORDER BY c2 DESC, c1 ASC LIMIT 1
) AS res;
c1	c2
t1a	3
DROP TABLE t1, t2;
#
# Bug #58970 Problem Subquery (without referencing a table) 
#            and Order By
#
SELECT(SELECT 0 AS a UNION SELECT 1 AS a ORDER BY a ASC  LIMIT 1) AS dev;
dev
0
SELECT(SELECT 0 AS a UNION SELECT 1 AS a ORDER BY a DESC LIMIT 1) AS dev;
dev
1
SELECT(SELECT 0 AS a FROM dual UNION SELECT 1 AS a FROM dual ORDER BY a ASC  LIMIT 1) AS dev;
dev
0
SELECT(SELECT 0 AS a FROM dual UNION SELECT 1 AS a FROM dual ORDER BY a DESC LIMIT 1) AS dev;
dev
1
SELECT(SELECT 1 AS a ORDER BY a) AS dev;
dev
1
SELECT(SELECT 1 AS a LIMIT 1) AS dev;
dev
1
SELECT(SELECT 1 AS a FROM dual ORDER BY a DESC LIMIT 1) AS dev;
dev
1
#
# Bug #17059925 : UNIONS COMPUTES ROWS_EXAMINED INCORRECTLY
#
SET @old_slow_query_log= @@global.slow_query_log;
SET @old_log_output= @@global.log_output;
SET @old_long_query_time= @@long_query_time;
SET GLOBAL log_output= "TABLE";
SET GLOBAL slow_query_log= ON;
SET SESSION long_query_time= 0;
CREATE TABLE t17059925 (a INT);
CREATE TABLE t2 (b INT);
CREATE TABLE t3 (c INT);
INSERT INTO t17059925 VALUES (1), (2), (3);
INSERT INTO t2 VALUES (4), (5), (6);
INSERT INTO t3 VALUES (7), (8), (9);
TRUNCATE table mysql.slow_log;
SELECT * FROM t17059925 UNION SELECT * FROM t2 UNION SELECT * FROM t3;
a
1
2
3
4
5
6
7
8
9
SELECT sql_text, rows_examined FROM mysql.slow_log WHERE sql_text LIKE '%SELECT%t17059925%';
sql_text	rows_examined
SELECT * FROM t17059925 UNION SELECT * FROM t2 UNION SELECT * FROM t3	18
DROP TABLE t17059925, t2, t3;
SET @@long_query_time= @old_long_query_time;
SET @@global.log_output= @old_log_output;
SET @@global.slow_query_log= @old_slow_query_log;
#
# lp:1010729: Unexpected syntax error from UNION
# (bug #54382) with single-table join nest      
#
CREATE TABLE t1 (a int);
CREATE TABLE t2 (b int);
CREATE TABLE t3 (c int);
SELECT a FROM t1 UNION SELECT b FROM t2 JOIN (t3) ON ( t2.b = t3.c );
a
DROP TABLE t1, t2, t3;
CREATE TABLE t1 (pk int NOT NULL);
CREATE TABLE t2 (pk int NOT NULL, fk int NOT NULL);
SELECT t1.pk FROM t1 LEFT JOIN (t2) ON (t1.pk = t2.fk)
UNION
SELECT t1.pk FROM t1 LEFT JOIN (t2) ON (t1.pk = t2.fk);
pk
DROP TABLE t1,t2;
create table t1 (a int);
insert t1 values (1),(2),(3),(1);
explain select 1 from dual where exists (select max(a) from t1 group by a union select a+2 from t1);
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	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	4	Using temporary
3	UNION	t1	ALL	NULL	NULL	NULL	NULL	4	
NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
drop table t1;
#
# MDEV-6868:MariaDB  server crash ( select with union and order by
# with subquery )
#
CREATE TABLE t1 ( id INTEGER, sample_name1 VARCHAR(100), sample_name2 VARCHAR(100), PRIMARY KEY(id) );
INSERT INTO t1 ( id, sample_name1, sample_name2 ) VALUES ( 1, 'aaaa', 'bbbb' ), ( 2, 'cccc', 'dddd' );
(
SELECT sample_name1 AS testname FROM t1
)
UNION
(
SELECT sample_name2 AS testname FROM t1 C ORDER BY (SELECT T.sample_name1 FROM t1 T WHERE T.id = C.id)
)
;
testname
aaaa
cccc
bbbb
dddd
drop table t1;
#
# MDEV-10172: UNION query returns incorrect rows outside
# conditional evaluation
#
create table t1 (d datetime not null primary key);
insert into t1(d) values ('2016-06-01'),('2016-06-02'),('2016-06-03'),('2016-06-04');
select * from
(
select * from t1 where d between '2016-06-02' and '2016-06-05'
	union
(select * from t1 where d < '2016-06-05' order by d desc limit 1)
) onlyJun2toJun4
order by d;
d
2016-06-02 00:00:00
2016-06-03 00:00:00
2016-06-04 00:00:00
drop table t1;
End of 5.0 tests
create table t1 (a int, b int);
insert into t1 values (1,1),(2,2),(3,3);
create table t2 (c varchar(30), d varchar(30));
insert into t1 values ('1','1'),('2','2'),('4','4');
create table t3 (e int, f int);
insert into t3 values (1,1),(2,2),(31,31),(32,32);
select e,f, (e , f) in (select e,b from t1 union select c,d from t2) as sub from t3;
e	f	sub
1	1	1
2	2	1
31	31	0
32	32	0
select avg(f), (e , f) in (select e,b from t1 union select c,d from t2) as sub from t3 group by sub;
avg(f)	sub
31.5000	0
1.5000	1
drop table t1,t2,t3;
#
# MDEV-14715 Assertion `!table || (!table->read_set ||
# bitmap_is_set(table->read_set, field_index))'
# failed in Field_num::val_decimal
#
CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM;
CREATE VIEW v1 AS SELECT * FROM t1;
INSERT INTO t1 VALUES (1, NULL),(3, 4);
(SELECT a, sum(a) AS f FROM v1 group by a ORDER BY b + sum(a))
UNION
(SELECT 2, 2);
a	f
1	1
3	3
2	2
(SELECT a, sum(a) AS f FROM v1 group by a ORDER BY b + 1)
UNION
(SELECT 2, 2);
a	f
1	1
3	3
2	2
SELECT a, b FROM t1
UNION
(SELECT a, VAR_POP(a) AS f FROM v1 GROUP BY a ORDER BY b/a );
a	b
1	NULL
3	4.0000
1	0.0000
3	0.0000
DROP TABLE t1;
(SELECT a, sum(a) AS f FROM v1 group by a ORDER BY b + 1)
UNION
(SELECT 2, 2);
ERROR HY000: View 'test.v1' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
DROP VIEW v1;
(SELECT a, sum(a) AS f FROM v1 group by a ORDER BY b + 1)
UNION
(SELECT 2, 2);
ERROR 42S02: Table 'test.v1' doesn't exist
#
# Bug#27197235 USER VARIABLE + UINON + DECIMAL COLUMN RETURNS
#              WRONG VALUES
#
SET NAMES utf8;
SET @advertAcctId = 1000003;
select @advertAcctId as a from dual union all select 1.0 from dual;
a
1000003.0
1.0
SET NAMES latin1;
SET @advertAcctId = 1000003;
select @advertAcctId as a from dual union all select 1.0 from dual;
a
1000003.0
1.0
#
# MDEV-13784: query causes seg fault
#
CREATE TABLE t1 (`bug_id` int NOT NULL PRIMARY KEY, `product_id` int NOT NULL);
INSERT INTO t1 VALUES (45199,1184);
CREATE TABLE t2 (`product_id` int NOT NULL,`userid` int NOT NULL, PRIMARY KEY (`product_id`,`userid`));
INSERT INTO t2 VALUES (1184,103),(1184,624),(1184,1577),(1184,1582);
CREATE TABLE t3 (`id` int NOT NULL  PRIMARY KEY,`name` varchar(64));
CREATE TABLE t4 ( `userid` int NOT NULL PRIMARY KEY, `login_name` varchar(255));
INSERT INTO t4 VALUES (103,'foo'),(624,'foo'),(1577,'foo'),(1582,'foo');
CREATE TABLE t5 (`id` int NOT NULL PRIMARY KEY, `name` varchar(64));
explain select
(
select login_name from t4 where userId = (
select userid from t2 where product_id = t1.product_id
union
select userid from t2 where product_id = (
select id from t5 where name = (select name from t3 where id = t1.product_id)) limit 1 )
) as x  from t1 where (t1.bug_id=45199);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	system	PRIMARY	NULL	NULL	NULL	1	
2	SUBQUERY	t4	eq_ref	PRIMARY	PRIMARY	4	func	1	Using where
3	SUBQUERY	t2	ref	PRIMARY	PRIMARY	4	const	4	Using index
4	UNION	t2	ref	PRIMARY	PRIMARY	4	func	1	Using where; Using index
5	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
6	SUBQUERY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
NULL	UNION RESULT	<union3,4>	ALL	NULL	NULL	NULL	NULL	NULL	
select
(
select login_name from t4 where userId = (
select userid from t2 where product_id = t1.product_id
union
select userid from t2 where product_id = (
select id from t5 where name = (select name from t3 where id = t1.product_id)) limit 1 )
) as x  from t1 where (t1.bug_id=45199);
x
foo
drop table t1, t2, t3, t4, t5;
End of 5.5 tests
#
# WL#1763 Avoid creating temporary table in UNION ALL
#
EXPLAIN SELECT 1 UNION ALL SELECT 1 LIMIT 1 OFFSET 1;
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	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
# Bug #17579498 CHANGES IN DATATYPE OF THE RESULT QUERY IN UNION.
CREATE TABLE t1 (a TIME);
CREATE TABLE t2 (b DATETIME);
CREATE TABLE t3
SELECT a FROM t1 UNION ALL SELECT b FROM t2;
SELECT column_name, column_type
FROM information_schema.columns
WHERE TABLE_NAME='t3';
column_name	column_type
a	datetime
DROP TABLE t1, t2, t3;
# Bug #17602922 RESULT DIFFERENCES IN UNION QUERIES WITH IN
# (SUBQUERY-UNION ALL)
CREATE TABLE t1 (a VARCHAR(1));
INSERT INTO t1 VALUES (NULL);
INSERT INTO t1 VALUES (NULL);
INSERT INTO t1 VALUES ('j');
INSERT INTO t1 VALUES ('k');
INSERT INTO t1 VALUES ('r');
INSERT INTO t1 VALUES ('r');
INSERT INTO t1 VALUES ('h');
SELECT a FROM t1 WHERE a IN (SELECT 'r' FROM t1 UNION ALL SELECT 'j');
a
j
r
r
CREATE TABLE t2
SELECT a FROM t1 WHERE a IN (SELECT 'r' FROM t1 UNION ALL SELECT 'j');
SELECT * FROM t2;
a
j
r
r
DROP TABLE t1, t2;
CREATE TABLE t1 (a INT PRIMARY KEY);
CREATE TABLE t2 (a INT PRIMARY KEY);
INSERT INTO t2 VALUES (1);
SELECT a, SUM(a) FROM t2 UNION ALL SELECT a, MIN(a) FROM t1 ;
a	SUM(a)
1	1
NULL	NULL
SELECT FOUND_ROWS();
FOUND_ROWS()
2
DROP TABLE t1, t2;
# Bug #17669551 CRASH/ASSERT AT SELECT_CREATE::PREPARE2 AT
# SQL_INSERT.CC
CREATE TABLE t1 (a INT);
CREATE TABLE t2 SELECT a, a FROM t1 UNION ALL SELECT a, a FROM t1;
ERROR 42S21: Duplicate column name 'a'
DROP TABLE t1;
# Bug #17694956 RESULT DIFFERENCES IN UNION ALL QUERIES WITH LIMIT
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1);
(SELECT a FROM t1 ORDER BY a LIMIT 0) UNION ALL SELECT a FROM t1;
a
1
DROP TABLE t1;
# Bug #17708480 FOUND_ROWS() VALUE DO NOT MATCH WITH UNION ALL QUERIES
CREATE TABLE t1 (a INT) ENGINE=MEMORY;
CREATE TABLE t2 (a INT) ENGINE=MEMORY;
INSERT INTO t2 VALUES (1);
SELECT COUNT(*) FROM (
SELECT                     * FROM t2 UNION ALL SELECT * FROM t1) q;
COUNT(*)
1
SELECT SQL_CALC_FOUND_ROWS * FROM t2 UNION ALL SELECT * FROM t1;
a
1
SELECT FOUND_ROWS();
FOUND_ROWS()
1
SELECT COUNT(*) FROM (
SELECT                     * FROM t1 UNION ALL SELECT * FROM t2) q;
COUNT(*)
1
SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION ALL SELECT * FROM t2;
a
1
SELECT FOUND_ROWS();
FOUND_ROWS()
1
DROP TABLE t1, t2;
# End of WL1763 tests
#
# Bug mdev-6874: crash with UNION ALL in a subquery
#
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES (1,1), (2,8);
SELECT * FROM t1 t1_1 LEFT JOIN t1 t1_2 ON ( t1_2.b = t1_1.a )
WHERE t1_2.b NOT IN ( SELECT 4 UNION ALL SELECT 5 );
a	b	a	b
1	1	1	1
DROP TABLE t1;
# Bug mdev-12788: UNION ALL + impossible having for derived
#                 with IN subquery in WHERE
#
CREATE TABLE t1 (i int) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1);
CREATE TABLE t2 (pk int PRIMARY KEY) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1),(2);
SELECT 1, 2
UNION ALL
SELECT i, COUNT(*) FROM (
SELECT * FROM t1 WHERE i IN ( SELECT pk FROM t2 )
) AS sq
GROUP BY i
HAVING i = 10;
1	2
1	2
EXPLAIN EXTENDED SELECT 1, 2
UNION ALL
SELECT i, COUNT(*) FROM (
SELECT * FROM t1 WHERE i IN ( SELECT pk FROM t2 )
) AS sq
GROUP BY i
HAVING i = 10;
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	UNION	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
Warnings:
Note	1003	/* select#1 */ select 1 AS `1`,2 AS `2` union all /* select#2 */ select 1 AS `i`,count(0) AS `COUNT(*)` from `test`.`t2` where 0 group by 1 having 1
DROP TABLE t1,t2;
#
# MDEV-10120: Wrong result of UNION .. ORDER BY GROUP_CONCAT()
#
CREATE TABLE t1 (a INT);
INSERT t1 VALUES (1),(2),(3);
(SELECT 1 AS a) UNION (SELECT a FROM t1 GROUP BY a) ORDER BY GROUP_CONCAT(a);
ERROR HY000: Expression #1 of ORDER BY contains aggregate function and applies to a UNION
DROP TABLE t1;
#
# Start of 10.3 tests
#
#
# MDEV-12619 UNION creates excessive integer column types for integer literals
#
CREATE TABLE t1 AS SELECT 1;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `1` int(1) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE OR REPLACE TABLE t1 AS SELECT 1 UNION SELECT 1;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `1` int(2) NOT NULL DEFAULT 0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE OR REPLACE TABLE t1 AS SELECT * FROM (SELECT 1 UNION SELECT 1) AS t0;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `1` int(2) NOT NULL DEFAULT 0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
#
# MDEV-9495 Wrong field type for a UNION of a signed and an unsigned INT expression
#
CREATE TABLE t1 (a INT, b INT UNSIGNED);
INSERT INTO t1 VALUES (0x7FFFFFFF,0xFFFFFFFF);
CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` decimal(10,0) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * FROM t2 ORDER BY a;
a
2147483647
4294967295
DROP TABLE t2;
CREATE TABLE t2 AS SELECT COALESCE(a,b), COALESCE(b,a) FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `COALESCE(a,b)` decimal(10,0) DEFAULT NULL,
  `COALESCE(b,a)` decimal(10,0) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * FROM t2;
COALESCE(a,b)	COALESCE(b,a)
2147483647	4294967295
DROP TABLE t2;
DROP TABLE t1;
#
# MDEV-9497 UNION and COALESCE produce different field types for DECIMAL+INT
#
CREATE TABLE t1 AS SELECT COALESCE(10.1,CAST(10 AS UNSIGNED)) AS a;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` decimal(3,1) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE OR REPLACE TABLE t1 AS SELECT 10.1 AS a UNION SELECT CAST(10 AS UNSIGNED);
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` decimal(3,1) NOT NULL DEFAULT 0.0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
#
# MDEV-12594 UNION between fixed length double columns does not always preserve scale
#
CREATE TABLE t1 (a FLOAT(20,4), b FLOAT(20,3), c FLOAT(20,4));
INSERT INTO t1 VALUES (1111,2222,3333);
CREATE TABLE t2 AS SELECT a FROM t1 UNION SELECT a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` float(20,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
CREATE OR REPLACE TABLE t2 SELECT a FROM t1 UNION SELECT c FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` float(20,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
CREATE OR REPLACE TABLE t2 SELECT b FROM t1 UNION SELECT b FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `b` float(20,3) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
CREATE OR REPLACE TABLE t2 SELECT c FROM t1 UNION SELECT c FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `c` float(20,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
CREATE OR REPLACE TABLE t2 SELECT c FROM t1 UNION SELECT a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `c` float(20,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
CREATE OR REPLACE TABLE t2 AS SELECT a FROM t1 UNION SELECT b FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` float(21,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
CREATE OR REPLACE TABLE t2 AS SELECT b FROM t1 UNION SELECT a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `b` float(21,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
DROP TABLE t1;
# Corner case
CREATE TABLE t1 (a FLOAT(255,4), b FLOAT(255,3));
INSERT INTO t1 VALUES (1111,2222);
CREATE OR REPLACE TABLE t2 AS SELECT b FROM t1 UNION SELECT a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `b` float(255,4) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
DROP TABLE t1;
#
# MDEV-12595 UNION converts INT to BIGINT
#
CREATE TABLE t1 AS SELECT
1,
-1,
COALESCE(1,1),
COALESCE(-1,-1),
COALESCE(1,-1),
COALESCE(-1,1);
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `1` int(1) NOT NULL,
  `-1` int(2) NOT NULL,
  `COALESCE(1,1)` int(2) NOT NULL,
  `COALESCE(-1,-1)` int(2) NOT NULL,
  `COALESCE(1,-1)` int(2) NOT NULL,
  `COALESCE(-1,1)` int(2) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE TABLE t1 AS SELECT 1 AS c1,1 AS c2,-1 AS c3,-1 AS c4 UNION SELECT 1,-1,1,-1;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` int(2) NOT NULL DEFAULT 0,
  `c2` int(2) NOT NULL DEFAULT 0,
  `c3` int(2) NOT NULL DEFAULT 0,
  `c4` int(2) NOT NULL DEFAULT 0
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
#
# MDEV-12599 UNION is not symmetric when mixing INT and CHAR
#
CREATE OR REPLACE TABLE t1 AS SELECT 1 AS c1, 'a' AS c2 UNION SELECT 'a', 1;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` varchar(1) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT '',
  `c2` varchar(1) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE OR REPLACE TABLE t1 AS SELECT 11112222 AS c1, 'a' AS c2 UNION SELECT 'a', 11112222;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` varchar(8) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT '',
  `c2` varchar(8) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE OR REPLACE TABLE t1 AS SELECT 111122223333 AS c1, 'a' AS c2 UNION SELECT 'a', 111122223333;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` varchar(12) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT '',
  `c2` varchar(12) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE OR REPLACE TABLE t1 AS SELECT 1111222233334444 AS c1, 'a' AS c2 UNION SELECT 'a', 1111222233334444;
SHOW CREATE TABLE t1;
Table	Create Table
t1	CREATE TABLE `t1` (
  `c1` varchar(16) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT '',
  `c2` varchar(16) CHARACTER SET latin1 COLLATE latin1_swedish_ci NOT NULL DEFAULT ''
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE TABLE t1 (a INT(3), b VARCHAR(1));
CREATE TABLE t2 AS SELECT a,b FROM t1 UNION SELECT b,a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(11) DEFAULT NULL,
  `b` varchar(11) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
DROP TABLE t1;
CREATE TABLE t1 (a BIGINT(3), b VARCHAR(1));
CREATE TABLE t2 AS SELECT a,b FROM t1 UNION SELECT b,a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(20) DEFAULT NULL,
  `b` varchar(20) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
DROP TABLE t1;
CREATE TABLE t1 (a BIGINT(12), b VARCHAR(1));
CREATE TABLE t2 AS SELECT a,b FROM t1 UNION SELECT b,a FROM t1;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `a` varchar(20) DEFAULT NULL,
  `b` varchar(20) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t2;
DROP TABLE t1;
#
# MDEV-13232: Assertion `(&(&share->intern_lock)->m_mutex)->count > 0 &&
# pthread_equal(pthread_self(), (&(&share->intern_lock)->m_mutex)->
# thread)' failed in _ma_state_info_write
#
CREATE TABLE t1 (c1 CHAR(8));
INSERT INTO t1 VALUES ('10'),('-10');
CREATE TABLE t2 (c2 CHAR);
SET @a= CAST('10' AS CHAR);
SELECT c1 FROM t1 UNION SELECT - @a FROM t2;
c1
10
-10
drop table t1,t2;
#
# MDEV-18700: EXPLAIN EXTENDED for query with UNION ALL
#             after INTERSECT/EXCEPT operations
#
create table t1 (a int);
insert into t1 values (3), (1), (7), (3), (2), (7), (4);
create table t2 (a int);
insert into t2 values (4), (5), (9), (1), (8), (9);
create table t3 (a int);
insert into t3 values (8), (1), (8), (2), (3), (7), (2);
explain extended
select * from t2 where a < 5
intersect
select * from t3 where a < 5
union all
select * from t1 where a > 4;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	100.00	Using where
2	INTERSECT	t3	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
3	UNION	t1	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
NULL	UNIT RESULT	<unit1,2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where `test`.`t2`.`a` < 5 intersect /* select#2 */ select `test`.`t3`.`a` AS `a` from `test`.`t3` where `test`.`t3`.`a` < 5 union all /* select#3 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 4
explain extended
select * from t2 where a < 5
except
select * from t3 where a < 5
union all
select * from t1 where a > 4;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	6	100.00	Using where
2	EXCEPT	t3	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
3	UNION	t1	ALL	NULL	NULL	NULL	NULL	7	100.00	Using where
NULL	UNIT RESULT	<unit1,2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`a` AS `a` from `test`.`t2` where `test`.`t2`.`a` < 5 except /* select#2 */ select `test`.`t3`.`a` AS `a` from `test`.`t3` where `test`.`t3`.`a` < 5 union all /* select#3 */ select `test`.`t1`.`a` AS `a` from `test`.`t1` where `test`.`t1`.`a` > 4
drop table t1,t2,t3;
#
# MDEV-24387: Wrong number of decimal digits in certain UNION/Subqery
#             constellation
#
SELECT CAST(1 AS UNSIGNED) UNION ALL SELECT * from (SELECT NULL) t;
Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
def					CAST(1 AS UNSIGNED)	246	2	1	Y	32896	0	63
CAST(1 AS UNSIGNED)
1
NULL
SELECT CAST(1 AS SIGNED) UNION ALL SELECT * from (SELECT NULL) t;
Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
def					CAST(1 AS SIGNED)	3	2	1	Y	32896	0	63
CAST(1 AS SIGNED)
1
NULL
SELECT CAST(1 AS SIGNED) UNION ALL SELECT * from (SELECT CAST(1 AS UNSIGNED)) t;
Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
def					CAST(1 AS SIGNED)	246	11	1	N	32897	0	63
CAST(1 AS SIGNED)
1
1
SELECT CAST(1 AS UNSIGNED) UNION ALL SELECT NULL;
Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
def					CAST(1 AS UNSIGNED)	246	2	1	Y	32896	0	63
CAST(1 AS UNSIGNED)
1
NULL
SELECT CAST(1 AS UNSIGNED) UNION ALL SELECT CAST(1 AS SIGNED);
Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
def					CAST(1 AS UNSIGNED)	246	2	1	N	32897	0	63
CAST(1 AS UNSIGNED)
1
1
#
# MDEV-24511 null field is created with CREATE..SELECT
#
set @save_default_storage_engine=@@default_storage_engine;
SET @@default_storage_engine=MEMORY;
CREATE TABLE t1 SELECT NULL UNION SELECT NULL;
ALTER TABLE t1 ADD INDEX (`PRIMARY`);
ERROR 42000: Key column 'PRIMARY' doesn't exist in table
CREATE TABLE t2 SELECT NULL;
SHOW CREATE TABLE t2;
Table	Create Table
t2	CREATE TABLE `t2` (
  `NULL` binary(0) DEFAULT NULL
) ENGINE=MEMORY DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
CREATE TABLE t3 SELECT NULL UNION SELECT NULL;
SHOW CREATE TABLE t3;
Table	Create Table
t3	CREATE TABLE `t3` (
  `NULL` binary(0) DEFAULT NULL
) ENGINE=MEMORY DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
CREATE OR REPLACE TABLE t4 SELECT NULL UNION SELECT NULL;
SHOW CREATE TABLE t4;
Table	Create Table
t4	CREATE TABLE `t4` (
  `NULL` binary(0) DEFAULT NULL
) ENGINE=MEMORY DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
ALTER TABLE t4 ADD INDEX (`NULL`);
DROP TABLE t1, t2, t3, t4;
set @@default_storage_engine=@save_default_storage_engine;
#
# MDEV-29022: add_slave destroy child list and has dead code
# (test added to be sure that ordering by several subqueries works)
#
create table t1 (aa int);
insert into t1 values (-1),(0),(1),(2),(3),(4),(5),(6),(98),(99),(100),(102);
create table t2 (a int, b int);
insert into t2 values (2,2),(2,3),(3,4),(3,5);
select a as a, b as b,
(select max(aa) from t1 where aa < t2.a) as c,
(select max(aa) from t1 where aa < t2.b) as d
from t2
union select 0 as a, 100 as b,
(select max(aa) from t1 where aa < 0) as c,
(select max(aa) from t1 where aa < 100) as d
union select 0 as a, 99 as b,
(select max(aa) from t1 where aa < 0) as c,
(select max(aa) from t1 where aa < 99) as d
order by (select max(aa) from t1 where aa < a),
(select max(aa) from t1 where aa < b);
a	b	c	d
0	99	-1	98
0	100	-1	99
2	2	1	1
2	3	1	2
3	4	2	3
3	5	2	4
select a as a, b as b,
(select max(aa) from t1 where aa < t2.a) as c,
(select 200 - max(aa) from t1 where aa < t2.b) as d
from t2
union select 0 as a, 100 as b,
(select max(aa) from t1 where aa < 0) as c,
(select 200 - max(aa) from t1 where aa < 100) as d
union select 0 as a, 99 as b,
(select max(aa) from t1 where aa < 0) as c,
(select 200 - max(aa) from t1 where aa < 99) as d
order by (select max(aa) from t1 where aa < a),
(select 200 - max(aa) from t1 where aa < b);
a	b	c	d
0	100	-1	101
0	99	-1	102
2	3	1	198
2	2	1	199
3	5	2	196
3	4	2	197
(select a as a, b as b,
(select max(aa) from t1 where aa < t2.a) as c,
(select max(aa) from t1 where aa < t2.b) as d
from t2)
union (select 0 as a, 100 as b,
(select max(aa) from t1 where aa < 0) as c,
(select max(aa) from t1 where aa < 100) as d)
union (select 0 as a, 99 as b,
(select max(aa) from t1 where aa < 0) as c,
(select max(aa) from t1 where aa < 99) as d)
order by (select max(aa) from t1 where aa < a),
(select max(aa) from t1 where aa < b);
a	b	c	d
0	99	-1	98
0	100	-1	99
2	2	1	1
2	3	1	2
3	4	2	3
3	5	2	4
(select a as a, b as b,
(select max(aa) from t1 where aa < t2.a) as c,
(select 200 - max(aa) from t1 where aa < t2.b) as d
from t2)
union (select 0 as a, 100 as b,
(select max(aa) from t1 where aa < 0) as c,
(select 200 - max(aa) from t1 where aa < 100) as d)
union (select 0 as a, 99 as b,
(select max(aa) from t1 where aa < 0) as c,
(select 200 - max(aa) from t1 where aa < 99) as d)
order by (select max(aa) from t1 where aa < a),
(select 200 - max(aa) from t1 where aa < b);
a	b	c	d
0	100	-1	101
0	99	-1	102
2	3	1	198
2	2	1	199
3	5	2	196
3	4	2	197
drop table t1,t2;
#
# MDEV-30066 (limit + offset) union all (...) limit = incorrect result
#
create table t1(id int primary key auto_increment, c1 int);
insert into t1(c1) values(1),(2),(3);
(select * from t1 where c1>=1 order by c1 desc limit 2,1) union all (select * from t1 where c1>1 order by c1 desc);
id	c1
1	1
2	2
3	3
(select * from t1 where c1>=1 order by c1 desc limit 2,1) union all (select * from t1 where c1>1 order by c1 desc) limit 2;
id	c1
1	1
2	2
drop table t1;
#
# End of 10.3 tests
#

# check union all & union distinct

select 1 as res union select 2 union select 1 union select 2;
res
1
2
select 1 as res union distinct select 2 union distinct select 1 union distinct select 2;
res
1
2
select 1 as res union all select 2 union all select 1 union all select 2;
res
1
2
1
2
select truncate(seq/2,0)+1 as res from seq_1_to_6 union select 2;
res
1
2
3
4
select truncate(seq/2,0)+1 as res from seq_1_to_6 union distinct select 2;
res
1
2
3
4
select truncate(seq/2,0)+1 as res from seq_1_to_6 union all select 2;
res
1
2
2
3
3
4
2
select 1 as res union all select 2 union distinct select 1 union all select 2;
res
1
2
2
select 1 as res union select 2 union all select 1 union distinct select 3;
res
1
2
3
select 1 as res union select 2 union all select 1 union distinct select 3 union all select 2;
res
1
2
3
2
select 1 as res union select 2 union all select 1 union distinct select 3 union all select 2 union distinct select 5;
res
1
2
3
5
select truncate(seq/2,0)+1 as res from seq_1_to_6 union all select 2 union all select 1 union distinct select 3 union all select 2;
res
1
2
3
4
2
