oracle 分页查询

oracle分页查询方式一:
select * from (select e.*,rownum rn from (select * from emp ) e where rownum <=3) A where A.rn >=1;

oracle分页查询方式二:
select * from (select e.*,rownum rn from (select * from emp) e) A where A.rn between 1 and 3;