比较实用的Oralce语句
基本伪列查询：
select * from (select rownum, e.* from emp e order by empno) where rownum < 11;
select * from (select rownum r, e.* from emp e order by empno) where r > 5 and r < 11;
汇总排名：
select emp.*, rank() over(order by sal desc) "工资排名" from emp;
select emp.*, rank() over(partition by deptno order by sal desc) "工资排名" from emp;
select * from (select e.*, rank() over(order by empno) emp_rank from emp e) where emp_rank = 3;
