摘要: select empno,ename,r from (select empno,ename,rownum r from emp) where r4 select empno,ename,r from (select empno,ename,rownum r from emp where rownum4 阅读全文
posted @ 2017-08-26 21:01 danawill 阅读(386) 评论(0) 推荐(0) 编辑