日期:2014-05-17 浏览次数:20961 次
select distinct t.a,t.b
from
(select '1' as a,'A' as b from dual
union all
select '1','A' from dual
union all
select '2','B' from dual
union all
select '2','B' from dual )t
--------------------------------
A B
1 1 A
2 2 B