mysql方案：select * from t order by idlimit 30,10
select * from t order by idlimit (pageNo-1)*pageSize, pageSize
oracle方案：select * from (select rownum r,* from t where r<=40) wherer>30
select * from (select rownum r,* from t where r<= pageNo* pageSize) wherer>( pageNo -1)* pageSize