比较难写的SQL语句

[jlduwei]

有一表A 字段F1,F2,F3,F4,F5

现在想把F1,F2,F3三个字段联合做主键后，导入另一相同结构的B表中，但是按三个字段联合做主键后有重复记录，
如何用一条SQL语句把不重复的记录选出来，再加上重复记录，并且重复记录选第一条。
类似
insert into b
(F1,F2,F3,F4,F5)
select


FROM A

[shaken]

insert into b
(F1,F2,F3,F4,F5)
select
distinct F1,F2,F3

FROM A

[shaken]

麻烦可以把我的回复删除吗，写错了！
55555……

[magnetmoon]

select a.* from 表A a
join (select distinct F1,F2,F3 from 表A b) as b
on a.f1=b.f1 and a.f2=b.f2 and a.f3=b.f3

[victorycyz]

select identity(int,1,1) as id,* into #t from A

insert into B
select a.f1,a.f2,a.f3,a.f4,a.f5
from #t a join
( select min(id) as nid
from #t
group by f1,f2,f3
) T
on a.id=T.id

drop table #t