睡觉前最后一问：求一个多表查询SQL语句！
表A
字段：
UID PID
1 1
1 2
2 1
3 2

表B
字段：
PID Des
1 'admin '
2 'super '

怎么实现取得UID=1的记录，即：Des既等于 'admin '，又等于 'super '的记录。

我知道用where exists (...where Des=) and exists (...where Des=)可以实现。
可是感觉效率不是很高的。怕数据量大了，速度慢。
那位大哥能给个优化的查询语句啊？谢谢~

(明天结帖)

[解决办法]
declare @ta table(UID int,PID int)
insert @ta
select 1, 1 union all
select 1, 2 union all
select 2, 1 union all
select 3, 2
declare @tb table(PID int,Des varchar(20))
insert @tb
select 1, 'admin ' union all
select 2, 'super '

SELECT UID FROM (select UID from @ta group by UID,PID) as t
group by UID having count(*)=(select count(*) from @tb)

/*
UID
-----------
1
*/
[解决办法]
select distinct uid from @ta a where
not exists
(select * from @tb where pid
not in (select pid from @ta b where a.uid=b.uid ))