--读取数据库中的m行到n行的数据


--sql2005
select * 
from (select *, ROW_NUMBER() over (order by username) as row_number from users) as temp 
where temp.row_number>=m and temp.row_number<=n;


--sql2000
select top (n-m+1) * from users where username not in 
(select top (m-1) username from users order by username) order by username;


--oracle
Select a.*  From  (Select b.*,Rownum r From （Select * from bbs Order By addtime desc） b bbs  ) a Where a.r<15 ;