求一个简的SQL

[rjthinking]

输入如下数据：
num name
1 a
1 b
2 c
2 a
3 a

输出如下结果
num name
1 a
1 b
1 c
2 a
2 b
2 c
3 a
3 b
3 c

[百年树人]

if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([num] int,[name] varchar(1))
insert [tb]
select 1,'a' union all
select 1,'b' union all
select 2,'c' union all
select 2,'a' union all
select 3,'a'
go

select *
from
(select num from tb group by num) a,
(select name from tb group by name) b

/**
num         name
----------- ----
1           a
1           b
1           c
2           a
2           b
2           c
3           a
3           b
3           c

(9 行受影响)
**/

[liyangfd]

if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([num] int,[name] varchar(1))
insert [tb]
select 1,'a' union all
select 1,'b' union all
select 2,'c' union all
select 2,'a' union all
select 3,'a'
go

select * from 
(select distinct num from tb  ) a , 
(select distinct name from tb ) b