SQL实现分组查询取前几条记录

 select b.OrderNumber,b.creationtime,b.remark  FROM 
 (
    SELECT a.OrderNumber,a.CreationTime,a.Remark 
    FROM [FortuneLabFord].[dbo].[SO_Log] a
    where a.SysId   IN
        (
         select TOP 3 SysId  from [FortuneLabFord].[dbo].[SO_Log] 
         where a.OrderNumber = SO_Log.OrderNumber ORDER BY a.CreationTime DESC
        )
) b  
group BY b.OrderNumber,b.creationtime,b.remark
ORDER BY b.OrderNumber