drop table if exists t1,t2,t3,t4;
create table t1(c1 int primary key, c2 int);
create table t2(c1 int primary key, c2 int);
create table t3(c1 int, c2 int primary key);
create table t4(c1 int primary key, c2 int);
insert into t1 values(1,1),(2,2),(3,3),(4,4),(5,5);
insert into t2 values(0,0),(2,2),(4,4),(6,6);
insert into t3 values(1,1),(3,3),(5,5),(7,7);
insert into t4 values(1,0),(2,0),(3,1),(4,1);
select * from t1 except select * from t1;
c1	c2
select * from t1 except all select * from t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select * from t1' at line 1
select * from t1 except select * from t2;
c1	c2
1	1
3	3
5	5
select * from t1 except all select * from t2;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select * from t2' at line 1
select * from t1 except select * from t3;
c1	c2
2	2
4	4
select * from t1 except all select * from t3;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select * from t3' at line 1
select * from t1 except select 1,1 from t1;
c1	c2
2	2
3	3
4	4
5	5
select * from t1 except all select 1,1 from t1;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select 1,1 from t1' at line 1
select * from t2 except select * from t3;
c1	c2
0	0
2	2
4	4
6	6
select * from t2 except all select * from t3;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select * from t3' at line 1
(select * from t2) except (select * from t2 where false);
c1	c2
0	0
2	2
4	4
6	6
(select * from t2) except all (select * from t2 where false);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all (select * from t2 where false)' at line 1
(select * from t2 where false) except (select * from t2);
c1	c2
(select * from t2 where false) except (select * from t2 where false);
c1	c2
select c2  from t4 except select 1 from t4;
c2
0
select c2  from t4 except all select 1 from t4;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select 1 from t4' at line 1
select c2  from t4 except select 0 from t4;
c2
1
select c2  from t4 except select c2  from t4;
c2
select c2  from t4 except select distinct c2  from t4;
c2
select distinct c2  from t4 except select distinct c2  from t4;
c2
select distinct c2  from t4 except all select distinct c2  from t4;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select distinct c2  from t4' at line 1
select distinct c2  from t4 except select c2  from t4;
c2
select distinct c2  from t4 except all select c2  from t4;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select c2  from t4' at line 1
select 0 from t4 except select c2 from t4;
0
select 1 from t4 except select 0 from t4;
1
1
select 1 from t4 except all select 0 from t4;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select 0 from t4' at line 1
(select * from t4 except (select * from t4 where c1=1) )except (select * from t4 where c1=2);
c1	c2
3	1
4	1
select * from t4 except (select * from t4 where c1=1) except (select * from t4 where c1=3);
c1	c2
2	0
4	1
select * from t4 except select 1,0 from t4 except select 3,1 from t4;
c1	c2
2	0
4	1
(select * from t4 where false) except (select * from t4 where false) except select * from t4;
c1	c2
select * from t4 except ((select * from t4 where c1=1) except (select * from t4 where c1=2));
c1	c2
2	0
3	1
4	1
select * from t4 except ((select * from t4 where c1=1) union (select * from t4 where c1=2));
c1	c2
3	1
4	1
drop table if exists t5,t6;
create table t5(c1 int primary key, c2 int);
create table t6(c1 int primary key, c2 int);
insert into t5 values(1,1),(2,2),(3,3),(4,4),(5,5),(6,2),(7,3),(8,6);
insert into t6 values(0,0),(2,2),(4,4),(6,6);
select c2 from t5 except select c2 from t6;
c2
1
3
5
select c2 from t5 except  all select c2 from t6;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your OceanBase version for the right syntax to use near 'all select c2 from t6' at line 1
drop table t1,t2,t3,t4,t5,t6;