多表查询练习第 9 题|学习笔记

列：*

表：emp e

条件：gal>(查询出公司的平均工资)

SELECT e.*, d.dname, m.ename, s.grade

FROM emp e, dept d, exp m, salgrade s

WHERE e.sal>(SELECT AVG(sal) FROM emp) AND e.deptno=d.deptno ANVD e.mgr=m.empno ANVD e.sal BETWEEN s.losal AND s.hisal

SELECT e.*, d.dname, m.ename, s.grade

FROM

emp e LEFT OUTER JOIN depton

 ON e.deptno=d.deptno

LEFT OUTER JOIN emp m ON e.ngrem.empno

LEFT OUTER JOIN salgrade s ON e.sal BETNEEN s.losal AND s.hisal

NHERE e.sal>(SELECT AVG(sal) FROM emp)

SELECT *FROM emp;

SELECT FROM dept;

SELECT FROM salgrade;