--2005以上版本
select item,price,sdate,edate from(
select *,row_number()over(partition by item order by edate desc)as id from tbl
) a where id=1
--2000版本
select * from tbl a where edate=(select max(edate) from tbl b where a.item=b.item)

------解决方案--------------------
SQL code
if object_id('[TB]') is not null drop table [TB]
go
create table [TB] (item int,price numeric(11,10),sdate datetime,edate datetime)
insert into [TB]
select 5930,2.6053800000,'2011-06-30 00:00:00.000','2011-07-12 16:40:55.873' union all
select 5930,2.8989900000,'2011-09-17 00:00:00.000','2011-09-23 10:54:09.357' union all
select 5930,2.4201600000,'2012-02-26 00:00:00.000','2012-02-20 12:00:40.543' union all
select 5936,0.1962000000,'2010-07-01 00:00:00.000','2010-07-14 00:00:00.000' union all
select 5936,0.2009400000,'2010-08-25 00:00:00.000','2010-09-21 13:45:53.140' union all
select 5936,0.2071600000,'2010-09-26 00:00:00.000','2010-10-26 13:53:33.390' union all
select 5936,0.2071630000,'2010-09-26 00:00:00.000','2010-11-04 14:47:27.357' union all
select 5936,0.2277860000,'2010-10-21 00:00:00.000','2010-12-10 18:15:51.373' union all
select 12200,1.4949600000,'2010-07-01 00:00:00.000','2010-07-14 00:00:00.000' union all
select 12200,1.4983400000,'2010-08-25 00:00:00.000','2010-09-21 13:45:53.140' union all
select 12200,1.5636100000,'2010-09-26 00:00:00.000','2010-10-26 13:53:33.390' union all
select 12200,1.5636050000,'2010-09-26 00:00:00.000','2010-11-04 14:47:27.357'

select * from [TB]



select distinct B.item,b.price,b.sdate,b.edate
from TB A
cross apply(select top 1 item,price,sdate,edate from TB where item = A.item order by edate desc) B


/*
5930    2.4201600000    2012-02-26 00:00:00.000    2012-02-20 12:00:40.543
5936    0.2277860000    2010-10-21 00:00:00.000    2010-12-10 18:15:51.373
12200    1.5636050000    2010-09-26 00:00:00.000    2010-11-04 14:47:27.357*/

------解决方案--------------------
SQL code

select a.* 
from tab a
inner join
(select item,max(edate) maxedate
from tab group by item) b
on a.item=b.item and a.edate=b.maxedate

------解决方案--------------------
SQL code

selct distinct item,max(edate) from 表 gourp by item

------解决方案--------------------