select * from salgrade; select * from emp; --显示员工的名字、工资及部门的名字 select e.ename,e.sal,d.dname from emp e,dept d where e.deptno=d.deptno; --显示部门编号为10的部门的员工的名字、工资及部门的名称 select e.ename,dept d where e.deptno=d.deptno and d.deptno=10; --显示员工的名字、工资及部门的名称,并按部门名称升序排序 select e.ename,dept d where e.deptno=d.deptno order by d.deptno; --显示员工的名字、工资及工资级别 select e.ename,g.grade from emp e,salgrade g where e.sal between g.losal and g.hisal; --显示SMITH上级领导的姓名(自连接,对同一张表进行连接查询) select ename from emp where empno=(select mgr from emp where ename='SMITH'); --显示各个员工的姓名和他的上级领导的名字 select e.ename,m.ename from emp e,emp m where e.mgr=m.empno; select e.*,m.* from emp e,emp m where e.mgr=m.empno; --显示SMITH同一部门的所有员工 select * from emp where deptno=(select deptno from emp where ename='SMITH'); select * from emp where deptno in(select deptno from emp where ename='SMITH'); --显示SMITH同一部门的所有员工，但不包含SMITH select * from emp where deptno=(select deptno from emp where ename='SMITH') and ename<>'SMITH'; select * from emp where deptno=(select deptno from emp where ename='SMITH') and ename!='SMITH'; --显示部门平资低于2000的部门号和它的平均工资 select deptno,avg(sal) from emp group by deptno having avg(sal)<2000; --查询部门号为10员工所参加的工作岗位相同的工作岗位的员工名字、岗位、工资、部门号 select * from emp where job in (select job from emp where deptno=10); select * from emp where job in(select job from emp where deptno=10); --查询比30号部门所有员工的工资高的员工姓名、工资、部门号 select * from emp where sal>(select max(sal) from emp where deptno=30); select * from emp where sal >all (select sal from emp where deptno=30); select * from emp where sal >(select max(sal) from emp where deptno=30); select * from emp where sal > all (select sal from emp where deptno=30); --查询比30号部门任意一个员工的工资高的员工姓名、工资、部门号 select * from emp where sal >(select min(sal) from emp where deptno=30); select * from emp where sal > any (select sal from emp where deptno=30); select * from emp where sal>(select min(sal) from emp where deptno=30); select * from emp where sal> any (select sal from emp where deptno=30); --查询与SMITH部门和工作岗位完全相同的所有员工信息(多列子查询) select * from emp where deptno=(select deptno from emp where ename='SMITH') and job=(select job from emp where ename='SMITH'); select * from emp where (deptno,job)=(select deptno,job from emp where ename='SMITH'); select * from emp where deptno=(select deptno from emp where ename='SMITH') and job=(select job from emp where ename='SMITH'); select * from emp where (deptno,job from emp where ename='SMITH'); --如何显示工资高于本部门平均工资的员工的信息(from中使用子查询) select avg(sal),deptno from emp group by deptno; select e.* from emp e,(select avg(sal) avgSal,deptno from emp group by deptno) d where e.deptno=d.deptno and e.sal>d.avgSal; select avg(sal),deptno from emp group by deptno; select * from emp e,deptno from emp group by deptno) d where e.deptno=d.deptno and e.sal>d.avgSal;
