请教一个select语句的写法

[LinuxCard]

表结构如下：fee(仓库编号，生效日期，费率)


仓库编号 生效日期 费率
1 2015-01-01 0.1
1 2015-02-02 0.2
2 2015-01-01 0.4

现在想查询每个仓库的最新的费率，想得到的如下的效果
仓库编号 生效日期 费率
1 2015-02-02 0.2
2 2015-01-01 0.4


请问，这样的语句应该怎么写比较好呢？

[Ekun_sky]

with fee(仓库编号,生效日期,费率) as (
select 1,'2015-01-01',0.1 union all
select 1,'2015-02-02', 0.2 union all
select 2,' 2015-01-01', 0.4)

select 仓库编号,生效日期,费率 from 
(select  ROW_NUMBER()over(partition by 仓库编号 order by 生效日期 desc) as aid,* from fee) as a
where a.aid=1

/*
仓库编号 生效日期 费率
1	2015-02-02	0.2
2	 2015-01-01	0.4
*/

[山巅客]

select * from free where (仓库编号，生效日期) in ( select 仓库编号，max(生效日期) from free group by 仓库编号 )

[吉普赛的歌]

;with as t (
	SELECT ROW_NUMBER() OVER (PARTITION BY [仓库编号] ORDER BY [生效日期] DESC) as rid,* FROM fee
)
SELECT 仓库编号,生效日期,费率 FROM t WHERE rid=1