--查询50到80行数据

--oracle
select * from(
select rownum r,t.* from (select * from testtable)t where rownum<80
)where r>=50;

--sqlserver
select * from (
select ROW_NUMBER() over(order by id) as rownum,*from ATTENCE
)a
where rownum between 50 and 80

--mysql
SELECT * FROM test LIMIT 50,80;