請教distinct select 問題

[henryzhanglz]

有一表a ,此表有a1,a2,a3,a4,a5欄位，其中a2的值是唯一的，但因其它欄位不同此表會有很多重復的a2記錄，我現在想找此表的所有欄位但a2是唯一的記錄，請高手幫忙

[lansquenet]

select a2,min(a1) a1,min(a3) a3,min(a4) a4,min(a5) a5 from tablename group by a2

看你取大还是取小:)

[maoyesky]

select identity(int,1,1) as nowid,* into #temp from tablename
go
select * from tablename where nowid in
(select min(nowid) from tablename group by a2)

[maoyesky]

上面寫錯了
select identity(int,1,1) as nowid,* into #temp from tablename
go
select * from tablename where nowid in
(select min(nowid) from #temp group by a2)

[CrazyFor]

select * from a aa where not exists (select 1 from a bb where aa.a2=bb.a2 and aa.a1<bb.a1)

[sdhdy]

--用集合函数
select a2,max(a1) a1,max(a3) a3,max(a4) a4,max(a5) a5 from tablename group by a2