求sql 语句 group by a 后选择每个分组里的第一条

[可小乐]

有两个列
id mytime
在group by id
后，如何选择每个ID 的第一条mytime?

[dearbinge]

SELECT * FROM TABLE
WHERE (SELECT COUNT(1) FROM TABLE T
       WHERE T.ID=ID AND mytime<T.mytime)<1

[dawugui]

[Quote=引用楼主 alonsov3v 的回复:]
有两个列
id mytime
在group by id
后，如何选择每个ID 的第一条mytime?
[/Quote]
select t.* from tb t where mytime = (select top 1 mytime from tb where id = t.id)

[--小F--]

select 
  a.mytime
from
  tb a
cross apply
  (select top 1 mytime from tb where id=a.id )b

[cuthbert_007]

select [id],(select top 1 mytime from #tb where [id] = a.[id] order by mytime ) as mytime
from #tb a
group by [id]