drop table if exists t;
create table t (c1 int, c2 int);
insert into t values (2, 3), (3, 3), (1, 1), (1, 2), (2, 2), (1, 3), (1,4), (1,5), (null, 2), (null, 3);
select * from t order by c1, c2;
c1	c2
NULL	2
NULL	3
1	1
1	2
1	3
1	4
1	5
2	2
2	3
3	3
select * from t order by c1 desc, c2;
c1	c2
3	3
2	2
2	3
1	1
1	2
1	3
1	4
1	5
NULL	2
NULL	3
select * from t order by c1 asc, c2 desc;
c1	c2
NULL	3
NULL	2
1	5
1	4
1	3
1	2
1	1
2	3
2	2
3	3
select * from t order by c2 desc, c1 desc;
c1	c2
1	5
1	4
3	3
2	3
1	3
NULL	3
2	2
1	2
NULL	2
1	1
select * from t order by c1 desc, c2 desc;
c1	c2
3	3
2	3
2	2
1	5
1	4
1	3
1	2
1	1
NULL	3
NULL	2
select * from t order by 3 desc, c1;
Error 1054: Unknown column '3' in 'order clause'
select c1 as a from t order by a;
a
NULL
NULL
1
1
1
1
1
2
2
3
select c1 as a from t order by c1;
a
NULL
NULL
1
1
1
1
1
2
2
3
select c1 as a from t order by c2, c1;
a
1
NULL
1
2
NULL
1
2
3
1
1
select c1 as a from t order by max(c1), c1;
a
2
select c1 as a from t order by c2, max(c2), c1;
a
2
select c1 from t group by c1 order by c1;
c1
NULL
1
2
3
select c1 from t group by c1 order by count(c1), c1;
c1
NULL
3
2
1
select c1 from t group by c1 order by count(c1) desc, c1;
c1
1
2
3
NULL
select c1 from t group by c1 order by max(c1), c1;
c1
NULL
1
2
3
select c1 from t group by c1 order by max(c1) desc, c1;
c1
3
2
1
NULL
select c1 from t group by c1 order by c2, c1;
c1
1
NULL
2
3
select c1 from t group by c1 order by c2 desc, c1;
c1
2
3
NULL
1
select c1 from t group by c1 order by max(c2), c1;
c1
NULL
2
3
1
select c1 from t group by c1 order by max(c2) desc, c1;
c1
1
NULL
2
3
select * from t group by c2 having c2 > 1 order by c2 desc, c1;
c1	c2
1	5
1	4
2	3
1	2
select c1 from t group by c2 having c2 > 1 order by c2 desc, c1;
c1
1
1
2
1
select * from t group by c2 having c2 > 1 order by c1 desc, c2;
c1	c2
2	3
1	2
1	4
1	5
select c2 from t group by c2 having c2 > 1 order by c1 desc, c2;
c2
3
2
4
5
select * from t having c2 > 1 order by c1 desc, c2;
c1	c2
3	3
2	2
2	3
1	2
1	3
1	4
1	5
NULL	2
NULL	3
select c2 from t having c2 > 1 order by c1 desc, c2;
c2
3
2
3
2
3
4
5
2
3
select c2 from t having count(c2) > 4 order by c1 desc, c2;
c2
3
select * from t group by c2 having c2 > 1 order by c1 desc, c2 desc;
c1	c2
2	3
1	5
1	4
1	2
select * from t group by c2 having c2 > 1 order by max(c1), c2;
c1	c2
1	4
1	5
1	2
2	3
select c2 from t group by c2 having c2 > 1 order by max(c1), c2;
c2
4
5
2
3
select * from t group by c2 having c2 > 1 order by max(c2), c1;
c1	c2
1	2
2	3
1	4
1	5
select * from t group by c2 having c2 > 1 order by 2 desc, c1;
c1	c2
1	5
1	4
2	3
1	2
select * from t group by c2 having c2 > 1 order by max(c2), c2 desc;
c1	c2
1	2
2	3
1	4
1	5
select * from t group by c2 having c2 > 1 order by 2 desc, max(c2), c1;
c1	c2
1	5
1	4
2	3
1	2
drop table if exists t;
create table t (c1 int, c2 int, c3 int);
insert into t SET c1=1, c2=2, c3 = 3;
insert into t SET c1=2, c2=3, c3 = 1;
insert into t SET c1=3, c2=1, c3 = 2;
select c1 as c2 from t order by c2 + c3, c1;
c2
3
2
1
select c1 as a from t order by c2 + c3, c1;
a
3
2
1
select c1 as a from t order by a + c3, c1;
a
2
1
3
select c1 as a from t order by c1 + c3, c1;
a
2
1
3
select c1 as c2 from t order by c2 + 1, c1;
c2
3
1
2
select c1 as c2, c2 from t order by c2, c1;
Error 1052: Column 'c2' in field list is ambiguous
select c1 as c2, c2 from t order by c2 + 1, c1;
c2	c2
3	1
1	2
2	3