declare @a table(a int ,b int,c int)
insert into @a values(101,1,2002)
insert into @a values(101,1,2003)
insert into @a values(101,2,2004)
insert into @a values(102,1,2002)
insert into @a values(102,2,2003)

select a,b,max(c)as 插入时间
from @a
where b = 1
group by a,b

------解决方案--------------------
SQL code
create table tb(a int,b int,c int)
insert into tb select 101,1,2002
insert into tb select 101,1,2003
insert into tb select 101,2,2004
insert into tb select 102,1,2002
insert into tb select 102,2,2003

select * from (select * from tb where b=1) t where not exists(
select 1 from tb where b=1 and  a=t.a and c>t.c
) 

select a,b,max(c)
from tb
where b=1
group by a,b

select * from tb t
where c in(select max(c) from tb where a=t.a and b=1)

------解决方案--------------------
SQL code
select t.* from tb t where b = 1 and 时间字段 = (select max(时间字段) from tb where b = 1 and a = t.a)

------解决方案--------------------
[Quote=引用:]
SQL code
select t.* from tb t where b = 1 and 时间字段 = (select max(时间字段) from tb where b = 1 and a = t.a)