找回密码
 立即注册

QQ登录

只需一步,快速开始

搜索
查看: 2334|回复: 0
收起左侧

数据库内连接

[复制链接]
ID:60076 发表于 2014-4-26 13:23 | 显示全部楼层 |阅读模式
1、select "E".ename,"E".deptno,"E".sal,"S".grade
from emp "E"
join salgrade "S"
on "E".sal between "S".losal and "S".hisal

2、select "T".*,"S".grade
from
(select "E".deptno, avg("E".sal) "avg_sal"
from emp "E"
join dept "D"
on "E".deptno = "D".deptno
group by "E".deptno) "T"
join salgrade "S"
on "T"."avg_sal" between "S".losal and "S".hisal

3、select "T".*, "D".dname, "S".grade
from
(select deptno, avg(sal) "avg_sal"
from emp "E"
group by "E".deptno) "T"
join dept "D"
on "T".deptno = "D".deptno
join salgrade "S"
on "T"."avg_sal" between "S".losal and "S".hisal

4、select empno from emp where empno in (select mgr from emp)

select  top 1"E".deptno, avg("E".sal) "avg_sal"
from emp "E"
group by "E".deptno
order by "avg_sal" desc

5、select top 3  "T".*, "D".dname,"S".grade
from
(select  ename, sal, deptno
from emp
where sal > (select min(sal) from emp)
) "T"
join dept "D"
on "T".deptno = "D".deptno
join salgrade "S"
on "T".sal between "S".losal and "S".hisal
order by sal asc

回复

使用道具 举报

您需要登录后才可以回帖 登录 | 立即注册

本版积分规则

小黑屋|51黑电子论坛 |51黑电子论坛6群 QQ 管理员QQ:125739409;技术交流QQ群281945664

Powered by 单片机教程网

快速回复 返回顶部 返回列表