SQLÓï¾äÇó½â

select * from tb

²éѯ½á¹û
c1  c2  c3
------------
1  aa  aa
1  bb  bb
1  cc  cc
2  dd  dd
2  ee  ee
2  ff  ff
3  gg  gg


ÎÒÏÖÔÚÏë¸ù¾Ýc1ÁУ¬²éѯ³ö¸ù¾Ýc1·Ö×éµÄÊý¾ÝµÄÇ°2Ìõ
(c1Ϊ1ÓÐ3Ìõ£¬ÄÇÎÒÖ»Òª2Ìõ  c1Ϊ2µÄÒ²ÓÐ3Ìõ£¬Ò²Ö»Òª2Ìõ  ¾ÍÊÇÕâÑù×Ó)
½á¹ûÓ¦¸ÃÊÇ
c1  c2  c3
------------
1  aa  aa
1  bb  bb
2  dd  dd
2  ee  ee
3  gg  gg

---

SQL code:
select * from [tb] t
where [c2]+[c3] in(select top 2 [c2]+[c3] from [tb] where [c1]=t.[c1])

---

SQL code:
select *
from tb a
where 2>(select count(*) from tb where c1=a.c1 and c2<a.c2)

---

SQL code:
---------------------------------
-- Author: liangCK СÁº
-- Title : ²éÿ¸ö·Ö×éÇ°NÌõ¼Ç¼
-- Date : 2008-11-13 17:19:23
---------------------------------

--> Éú³É²âÊÔÊý¾Ý: #T
IF OBJECT_ID('tempdb.dbo.#T') IS NOT NULL DROP TABLE