问个SQL问题

Question

表结构ID. CreatedOn 　　　　　　　　　　　　　　Pid1    2013-09-26 16:24:52.250                  11　　2013-09-26 16:24:52.327                 21　　2013-09-26 16:24:52.343                 32　　2013-09-27 15:09:07.703                 42　　2013-09-27 15:09:07.720                  52　　2013-09-27 15:09:07.720                  63　　2013-09-28 15:09:07.703                 73　　2013-09-28 15:09:07.720                  83　　2013-09-28 15:09:07.720                  9我想知道  如果按照ID来分组  按照CrteateOn作为条件我想取出最新更改的记录 该怎么SQL语句?注意可能不止3条ID为1或者2或者3的记录。但是CreateOn日期都是一样的

Answer 1

select * from TableA where id in (select id from TableA where CreatedON=(select Max(createdOn)  as createdon from TableA))

Answer 2

USE tempdbGOIF EXISTS(SELECT * FROM SYSOBJECTS WHERE NAME='TEMP')    DROP TABLE TEMPCREATE TABLE TEMP(
ID INT,
CREATED DATETIME,
PID INT)GOINSERT INTO TEMPVALUES(1,'2013-01-01 11:11:11',1),
(1,'2013-01-01 11:11:12',2),
(1,'2013-01-01 11:11:13',3),
(2,'2013-01-01 11:11:11',1),
(2,'2013-01-01 11:11:12',2),
(2,'2013-01-01 11:11:13',3),
(2,'2013-01-01 11:11:14',4),
(3,'2013-01-01 11:11:11',1),
(3,'2013-01-01 11:11:12',2),
(3,'2013-01-01 11:11:13',3),
(3,'2013-01-01 11:11:14',4)GOSELECT * FROM TEMP AS AWHERE NOT EXISTS(SELECT 0 FROM TEMP AS B WHERE A.ID=B.ID AND A.CREATED<B.CREATED)

Answer 3

select a.*

from table as a

        inner join (select id, max(CreatedOn) as CreatedOn

                        from table

                        group by id) as b on a.id=b.id and a.CreatedOn=b.CreatedOn