select 1 union ( select 2 union select 3);
explain extended
select 1 union ( select 2 union select 3);
select 1 union ( select 1 union select 1);
explain extended
select 1 union ( select 1 union select 1);
select 1 union all ( select 1 union select 1);
explain extended
select 1 union all ( select 1 union select 1);
select 1 union ( select 1 union all select 1);
explain extended
select 1 union ( select 1 union all select 1);
select 1 union select 1 union all select 1;
explain extended
select 1 union select 1 union all select 1;

(select 1 as a) union (select 2) order by a;
explain extended
(select 1 as a) union (select 2) order by a;
/* select#1 */ select 1 AS `a` union /* select#2 */ select 2 AS `2` order by `a`;
explain extended
/* select#1 */ select 1 AS `a` union /* select#2 */ select 2 AS `2` order by `a`;

select 1 union ( select 1 union (select 1 union (select 1 union select 1)));
explain extended all
select 1 union ( select 1 union (select 1 union (select 1 union select 1)));

--echo #
--echo # MDEV-6341: INSERT ... SELECT UNION with parenthesis
--echo #
create table t1 (a int, b int);
insert into t1 (select 1,1 union select 2,2);
select * from t1 order by 1;
delete from t1;
insert into t1 select 1,1 union select 2,2;
select * from t1 order by 1;
drop table t1;
CREATE OR REPLACE TABLE t1 AS SELECT 1 AS a UNION SELECT 2;
select * from t1 order by 1;
drop table t1;
CREATE OR REPLACE TABLE t1 AS (SELECT 1 AS a UNION SELECT 2);
select * from t1 order by 1;
drop table t1;
CREATE OR REPLACE VIEW v1 AS (SELECT 1 AS a);
show create view v1;
drop view v1;
CREATE OR REPLACE VIEW v1 AS SELECT 1 AS a UNION SELECT 2;
show create view v1;
drop view v1;
CREATE OR REPLACE VIEW v1 AS (SELECT 1 AS a UNION SELECT 2);
show create view v1;
drop view v1;


--echo #
--echo # MDEV-10028: Syntax error on ((SELECT ...) UNION (SELECT ...))
--echo #
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (10);
INSERT INTO t1 VALUES (20);
INSERT INTO t1 VALUES (30);

((SELECT a FROM t1) UNION (SELECT a FROM t1));
(SELECT * FROM t1 UNION SELECT * FROM t1);
((SELECT a FROM t1) LIMIT 1);
SELECT * FROM (SELECT 1 UNION (SELECT 2 UNION SELECT 3)) t1;
DROP TABLE t1;

--echo #
--echo # test of several levels of ORDER BY / LIMIT
--echo #
create table t1 (a int, b int);
insert into t1 (a,b) values (1, 100), (2, 200), (3,30), (4,4);

select a,b from t1 order by 1 limit 3;
(select a,b from t1 order by 1 limit 3) order by 2 limit 2;
(select 10,1000 union select a,b from t1 order by 1 limit 3) order by 2 limit 2;
((select a,b from t1 order by 1 limit 3) order by 2 limit 2) order by 1 limit 1;
((select a,b from t1 order by 1 limit 3) order by 2 limit 2) order by 1;

drop table t1;

--echo #
--echo # MDEV-16359: union with 3 selects in brackets
--echo #

select 1 union select 1 union select 1;
(select 1 union select 1 union select 1);
((select 1) union (select 1) union (select 1));

--echo #
--echo # MDEV-16357: union in brackets with tail
--echo #             union with tail in brackets
--echo #

CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES(1),(2),(3),(4);

CREATE TABLE t2 (a int);
INSERT INTO t2 VALUES (4),(5),(6),(7);

(SELECT a FROM t1  UNION SELECT a FROM t2) LIMIT 1;
(SELECT a FROM t1  UNION SELECT a FROM t2) ORDER BY a DESC;

(SELECT a FROM t1  UNION SELECT a FROM t2 LIMIT 1);

DROP TABLE t1,t2;

--echo #
--echo # MDEV-19324: ((SELECT ...) ORDER BY col ) LIMIT n
--echo #

create table t1 (a int);
insert into t1 values (10),(20),(30);

let $q1=
select a from t1 order by a desc limit 1;
eval $q1;
eval explain extended $q1;
eval explain format=json $q1;

let $q2=
(select a from t1 order by a desc) limit 1;
eval $q2;
eval explain extended $q2;
eval explain format=json $q2;

let $q1=
(select a from t1 where a=20 union select a from t1) order by a desc limit 1;
eval $q1;
eval explain extended $q1;
eval explain format=json $q1;

let $q2=
((select a from t1 where a=20 union select a from t1) order by a desc) limit 1;
eval $q2;
eval explain extended $q2;
eval explain format=json $q2;

drop table t1;

--echo #
--echo # MDEV-19363: ((SELECT ...) ORDER BY col ) LIMIT n UNION ...
--echo #

create table t1 (pk int);
insert into t1 values (5),(4),(1),(2),(3);

let $q=
((select * from t1 order by pk) limit 2) union (select * from t1 where pk > 4);
eval $q;
eval explain extended $q;
eval explain format=json $q;

drop table t1;

--echo #
--echo # MDEV-18689: parenthesis around table names and derived tables
--echo #

select * from ( mysql.db );

create table t1 (a int);
insert into t1 values (7), (2), (7);

select * from (t1);
select * from ((t1));
select * from (t1 t) where t.a > 5;
select * from ((t1 t)) where t.a > 5;

select * from ((select a, sum(a) from t1 group by a) t);
select * from (((select a, sum(a) from t1 group by a) t));

update (t1 t) set t.a=t.a+1;
select * from t1;

drop table t1;

--echo # End of 10.4 tests