数据按条件分组后最前N条

最近遇到一个数据库方面的问题,按要求分组后取前N条记录,如果没有N条则将现有的记录全部取出来,

Create table TopGroup

(

    ID int not null identity(1,1),

    [Type] varchar(128) not null,

    [Value] Numeric(10,2)

)

GO

Insert into TopGroup(Type,Value)

Select &＃39;C&＃39;,34 Union

select &＃39;C&＃39;,45 Union

select &＃39;C&＃39;,88 Union

select &＃39;C&＃43;&＃43;&＃39;,75 Union

select &＃39;C&＃43;&＃43;&＃39;,85 Union

select &＃39;C&＃43;&＃43;&＃39;,95 Union

select &＃39;Java&＃39;,87 Union

select &＃39;Java&＃39;,97 Union

select &＃39;Java&＃39;,63 Union

select &＃39;Java&＃39;,60 Union

select &＃39;Java&＃39;,82

Select * from TopGroup

--分组后取Value值较大的前两条记录

Select A.ID,A.Type,A.Value

From TopGroup A

Where (

       Select Count(*)

       From TopGroup B

       Where A.Type&＃61;B.Type And A.Value<&＃61;B.Value

       )<&＃61;2

GO

Drop Table TopGroup