github.com/matrixorigin/matrixone@v1.2.0/test/distributed/cases/union/union.sql (about) 1 drop table if exists t1; 2 drop table if exists t2; 3 create table t1(a int, b int); 4 insert into t1 values (1, 10),(2, 20); 5 create table t2(aa int, bb varchar(20)); 6 insert into t2 values (11, "aa"),(22, "bb"); 7 8 (select a from t1) order by b desc; 9 (((select a from t1) order by b desc)); 10 (((select a from t1))) order by b desc; 11 (((select a from t1 order by b desc) limit 1)); 12 (((select a from t1 order by b desc))) limit 1; 13 (select a from t1 union select aa from t2) order by a desc; 14 15 (select a from t1 order by a) order by a; 16 (((select a from t1 order by a))) order by a; 17 (((select a from t1) order by a)) order by a; 18 (select a from t1 limit 1) limit 1; 19 (((select a from t1 limit 1))) limit 1; 20 (((select a from t1) limit 1)) limit 1; 21 (select a from t1 union select aa from t2) order by aa; 22 select a from t1 union select a from t1; 23 drop table if exists t3; 24 create table t3( 25 a tinyint 26 ); 27 insert into t3 values (20),(10),(30),(-10); 28 drop table if exists t4; 29 create table t4( 30 col1 smallint, 31 col2 smallint unsigned, 32 col3 float, 33 col4 bool 34 ); 35 insert into t4 values(100, 65535, 127.0, 1); 36 insert into t4 values(300, 0, 1.0, 0); 37 insert into t4 values(500, 100, 0.0, 0); 38 insert into t4 values(200, 35, 127.0, 1); 39 insert into t4 values(200, 35, 127.44, 1); 40 select a from t3 union select col3 from t4 order by a; 41 drop table if exists t7; 42 CREATE TABLE t7 ( 43 a int not null, 44 b char (10) not null 45 ); 46 insert into t7 values(1,'a'),(2,'b'),(3,'c'),(3,'c'); 47 select * from (select * from t7 union all select * from t7 limit 2) a; 48 drop table if exists t2; 49 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); 50 INSERT INTO t2 (id, id_master, text1, text2) VALUES("1", "1", "foo1", "bar1"); 51 INSERT INTO t2 (id, id_master, text1, text2) VALUES("2", "1", "foo2", "bar2"); 52 INSERT INTO t2 (id, id_master, text1, text2) VALUES("3", "1", NULL, "bar3"); 53 INSERT INTO t2 (id, id_master, text1, text2) VALUES("4", "1", "foo4", "bar4"); 54 SELECT 1 AS id_master, 1 AS id, NULL AS text1, 'ABCDE' AS text2 UNION SELECT id_master, id, text1, text2 FROM t2 order by id; 55 DROP TABLE IF EXISTS t1; 56 DROP TABLE IF EXISTS t2; 57 CREATE TABLE t1(id INT NOT NULL, name CHAR(20) NOT NULL, sex CHAR(4) NOT NULL, PRIMARY KEY (id)); 58 CREATE TABLE t2(id VARCHAR(10) NOT NULL, name VARCHAR(20) NOT NULL, nation VARCHAR(20) NOT NULL, PRIMARY KEY(id)); 59 INSERT INTO t1() VALUES(1,'ronaldo','F'), (2,'kante','M'), (3,'noyer','F'),(4,'modrici','M'); 60 INSERT INTO t2() VALUES(1,'ronaldo','American'), (2,'kante','Franch'), (3,'noyer','Germany'),(4,'modrici','UK'); 61 (SELECT * FROM t1 WHERE id BETWEEN 1 AND 2 ORDER BY name) UNION ALL (SELECT * FROM t2 WHERE nation BETWEEN 'A' AND 'F' ORDER BY id DESC); 62 select * from (SELECT * FROM t1 UNION ALL SELECT * FROM t2) a where id > 1 and sex > 'F' order by id;