select * from 表 a where 发表时间=(select max(发表时间) from 表 where 类型=a.类型)

------解决方案--------------------
SQL code
--原始数据：@T
declare @T table(id int,类型 varchar(8),内容 int,发表时间 datetime)
insert @T
select 1,'&brvbarA',12344455,'2007-9-10' union all
select 2,'&brvbarB',34223424,'2007-9-12' union all
select 3,'&brvbarC',11111111,'2007-9-13' union all
select 1,'&brvbarA',12344455,'2007-10-10' union all
select 2,'&brvbarB',34223424,'2007-10-12'

select *

------解决方案--------------------
SQL code
--可以使用cross apply
create function dbo.myfunc(@id as int)
returns table
as
return 
select top(1) *  
from dbo.test
where id=@id
order by 发表时间 desc;
go

select b.id,b.类型,b.内容,b.发表时间
from dbo.test  a cross  apply dbo.myfunc(a.id) as b
group by b.id,b.类型,b.内容,b.发表时间;
go

-------------------
id          类型       内容          发表时间
----------- -------- ----------- -----------------------
1           A        12344455    2007-10-10 00:00:00.000
2           B        34223424    2007-10-12 00:00:00.000
3           C        11111111    2007-09-13 00:00:00.000

(3 row(s) affected)

------解决方案--------------------
create table T(id int,类型 varchar(8),内容 int,发表时间 datetime)
insert T
select 1,'&brvbarA',12344455,'2007-9-10' union all
select 2,'&brvbarB',34223424,'2007-9-12' union all
select 3,'&brvbarC',11111111,'2007-9-13' union all
select 1,'&brvbarA',12344455,'2007-10-10' union all
select 2,'&brvbarB',34223424,'2007-10-12'

select a.* from T a
inner join  
(
 select 类型,max(发表时间)as 发表时间 from T group by 类型  
)b  on a.类型=b.类型 and a.发表时间=b.发表时间
order by a.类型

--result:
1     &brvbarA	12344455	2007-10-10 00:00:00.000	
2     &brvbarB	34223424	2007-10-12 00:00:00.000	
3     &brvbarC	11111111	2007-09-13 00:00:00.000	


------解决方案--------------------
SQL code
select * from 表 a where 发表时间=(select top 1 发表时间 from 表 where 类型=a.类型 order by 发表时间)

------解决方案--------------------
create table tb (id  int ,lx char(2), lr char(20),fbsj datetime)
insert tb select 1 ,'A',     '12344455',   '2007-9-10' union all select  
2,'B',     '34223424',   '2007-9-12' union all select  
3,'C',     '11111111',   '2007-9-13' union all select  
1,'A',     '12344455',   '2007-10-10' union all select  
2,'B',     '34223424',   '2007-10-12'  
//最新的一条记录.
select * from tb a where   not exists (select * from tb where id=a.id and fbsj>a.fbsj )
//最早的一条记录
select * from tb a where   not exists (select * from tb where id=a.id and fbsj<a.fbsj )

------解决方案--------------------
declare @T table(id int,type varchar(8),text int,sdate datetime)
insert @T
select 1,'&brvbarA',12344455,'2007-9-10' union all
select 2,'&brvbarB',34223424,'2007-9-12' union all
select 3,'&brvbarC',11111111,'2007-9-13' union all
select 1,'&brvbarA',12344455,'2007-10-10' union all
select 2,'&brvbarB',34223424,'2007-10-12'


select id,type,text,max(sdate) sdate from (select id,type,text,sdate from @t group by type,id,text,sdate) a  group by id,type,text