Sqlserver取最近一分組中最新一條記錄

/* 1 用子查詢 可以過濾掉parentID為NULL的*/
select * from Bid_ProjectPackageAlteredDesignInfo t0
where exists
(
    select 1 from
    (
        select ParentID, max(AlterTime) as AlterTime
        from Bid_ProjectPackageAlteredDesignInfo 
        group by ParentID
    ) x
    where x.ParentID = t0.ParentID and x.AlterTime = t0.AlterTime
)
select a.*
 from Bid_ProjectPackageAlteredDesignInfo a
 inner join
 (select ParentID,
         max(AlterTime) 'AlterTime'
  from Bid_ProjectPackageAlteredDesignInfo 
  group by ParentID) b on a.ParentID=b.ParentID and a.AlterTime=b.AlterTime
 /*不可以過濾掉parentID為NULL的*/
select a.* 
 from Bid_ProjectPackageAlteredDesignInfo a 
 where not exists
 (
    select 1 from Bid_ProjectPackageAlteredDesignInfo b where b.ParentID=a.ParentID and b.AlterTime>a.AlterTime
  )



/* 2 用窗口函數 *//*不可以過濾掉parentID為NULL的*/
select * from
(
select ParentID,AlterTime
, max(AlterTime) over(partition by ParentID) as AlterTimeMax
from Bid_ProjectPackageAlteredDesignInfo
) x
where AlterTimeMax =AlterTime