select a.name,a.context,b.name,a.dateandtime from article a, type c
where a.id in (select top 3 id  from article b where a.typeid=b.typeid order by dateandtime desc)
and  a.typeid=b.typeid

------解决方案--------------------
SQL code
select m.name,m.context,n.name , m.dateandtime from
(
  select t.* from article t where dateandtime in (select top 3 dateandtime from article where typeid = t.typeid order by dateandtime desc) 
) m , type n
where m.typeid = t.id

------解决方案--------------------
SQL code
create table article(id int,name varchar(10),context varchar(20),typeid int,dateandtime datetime)
insert into article values(1 , 'test1', '<long text>', 1 , '2008/03/24 18:00:00') 
insert into article values(2 , 'test2', '<long text>', 1 , '2008/03/24 18:01:00') 
insert into article values(3 , 'test3', '<long text>', 2 , '2008/03/24 18:00:00') 
insert into article values(4 , 'test4', '<long text>', 2 , '2008/03/24 18:02:00') 
insert into article values(5 , 'test5', '<long text>', 2 , '2008/03/24 18:03:00') 
insert into article values(6 , 'test6', '<long text>', 2 , '2008/03/24 18:04:00')
create table type(Id int , name varchar(10))
insert into type values(1 ,'国际新闻') 
insert into type values(2 ,'国内新闻')
go

select m.name,m.context,n.name , m.dateandtime from
(
  select t.* from article t where dateandtime in (select top 3 dateandtime from article where typeid = t.typeid order by dateandtime desc) 
) m , type n
where m.typeid = n.id

drop table article, type

/*
name       context              name       dateandtime                                            
---------- -------------------- ---------- ------------------------------------------------------ 
test1      <long text>          国际新闻       2008-03-24 18:00:00.000
test2      <long text>          国际新闻       2008-03-24 18:01:00.000
test4      <long text>          国内新闻       2008-03-24 18:02:00.000
test5      <long text>          国内新闻       2008-03-24 18:03:00.000
test6      <long text>          国内新闻       2008-03-24 18:04:00.000

（所影响的行数为 5 行）
*/

------解决方案--------------------
sql2005

SQL code
select row_number() over (partition by a order by b)as row ,*
from(select 'a' a,'b' b union select 'a','c' union select 'b','a')a
/*
row                  a    b
-------------------- -