怎么在Oracle中查询最后三条数据

Question

表employee 共有n条数据，问怎么查询最后三条数据

Answer 1

select * from (select rownum,ename from emp order by rownum desc)where rownum<=3;
直接复制粘贴就可以求出来 要加记录 加在 ename 后面 不懂再问我

Answer 2

select * from (select rownum a,employee.* from employee order by id desc ) b where b.a>0 and rownum <=3;

Answer 3

先排序再查询
select top3 from employee order by desc
或者直接查询
select * from employee where id in (max(id),max（id)-1,max(id)-2)