求 sql语句

[smallcrocodile]

表tt
col1 col2 col3 col4
a b 1 2
b a 1 3
c b 2 1
a c 2 2
c a 3 3
a d 4 4
b c 3 2

分组显示
col1 col2 col3 col4
a b 1 2
a c 2 2
a d 4 4
b a 1 3
b c 3 2
c a 3 3
c b 2 1

[xxd_qd]

排序？
select * from tt order by col1, col2

[senlinzhiwang]

select * from tt order by col1,col3;

[yuchongjike]

select * from tt order by cast(col1)