1:查看与CLARK相同职位的员工
select ename,job from emp_xiangyoulu where job=(
select job from emp_xiangyoulu where ename='CLARK');
2:查看低于公司平均工资的员工
select ename,sal from emp_xiangyoulu where sal<(
select avg(sal) from emp_xiangyoulu);
3:查看与ALLEN同部门的员工
select ename,deptno from emp_xiangyoulu where deptno=(
select deptno from emp_xiangyoulu where ename='ALLEN');
4:查看平均工资低于20号部门平均工资的部门平均工资
select avg(sal),deptno from emp_xiangyoulu group by deptno having avg(sal)<(
select avg(sal) from emp_xiangyoulu where deptno=20);
select deptno,avg(sal) from emp_xiangyoulu group by deptno having avg(sal)<(
select avg(sal) from emp_xiangyoulu group by deptno having deptno=20);
5:查看低于自己所在部门平均工资的员工
select e.ename,e.sal from emp_xiangyoulu e join
(select avg(sal) avg_sal,deptno from emp_xiangyoulu group by deptno) m
on e.deptno=m.deptno where e.sal<m.avg_sal;
6:查看公司工资排名的第2-5名
select * from emp_xiangyoulu order by sal desc;
select * from (
select rownum rn,e.* from(
select ename,sal,deptno from emp_xiangyoulu order by sal desc) e)
where rn between 2 and 5;
select * from(
select ename,sal,deptno from emp_xiangyoulu order by sal desc)
where rownum<5;
select * from(
select rownum rn,ename,sal from emp_xiangyoulu order by sal desc)
where rn between 2 and 5;-->有问题,伪列的序号不是按照sal降序排列,而是提前生成好的;
SELECT ROWNUM rn,e.* FROM (
SELECT * FROM emp_xiangyoulu ORDER BY sal desc) e
WHERE rn BETWEEN 2 AND 5;--rn 标识符无效
select rownum,e.* from(
select * from emp_xiangyoulu order by sal desc)e
where rownum between 2 and 5;--无结果
select * from(
select rownum rn,e.* from(
select * from emp_xiangyoulu order by sal desc)e)
where rn between 2 and 5;
--查看公司工资排名的第6-10名
select * from(
select rownum rn,e.* from(
select * from emp_xiangyoulu order by sal desc)e)
where rn between 6 and 10;
--查看公司各部门薪资排名前两名的员工信息?
select * from(
select ename,sal,deptno,row_number() over (partition by deptno order by sal desc)rn
from emp_xiangyoulu)e
where e.rn<3;
7:查看CLERK职位的人数和其他职位的总人数各多少?
select count(job) from emp_xiangyoulu where job='CLERK';
select count(1),decode(
job,'CLERK','职员','其他职位')de from emp_xiangyoulu
group by decode(
job,'CLERK','职员','其他职位');
--统计10号,20部门以及其余别的的部门的员工人数;
select count(1),decode(
deptno,10,'10号部门',20,'20号部门','别的部门')de from emp_xiangyoulu
group by decode(
deptno,10,'10号部门',20,'20号部门','别的部门');
8:查看每个职位的平均工资排名
select job,avg(sal) a_sal from emp_xiangyoulu
group by job order by a_sal desc;
8.2:查看每个职位的员工工资排名
select ename,sal,job,row_number() over(partition by job order by sal desc)rn
from emp_xiangyoulu;
9:查看每个职位的工资排名，若工资一致，排名一致
select ename,sal,job,rank() over(partition by job order by sal desc)rn from emp_xiangyoulu;
10:查看每个职位的工资排名，若工资一致，排名一致，不跳名次。
select ename,sal,job,dense_rank() over (partition by job order by sal desc)rn
from emp_xiangyoulu;
11:分别查看:同部门同职位，同职位，以及所有员工的工资总和
select deptno,job,sum(sal) from emp_xiangyoulu
group by deptno,job;--结果不含工资总和；
select deptno,job,sum(sal) from emp_xiangyoulu
group by rollup(deptno,job);
12:分别查看:同部门同职位，同职位，同部门以及所有员工的工资总和
select deptno,job,sum(sal) from emp_xiangyoulu
group by cube(deptno,job);
13:分别查看同部门同职位和同职位的员工的工资总和
14:查看公司最高工资的员工的名字以及所在部门名称
select e.ename,d.dname from emp_xiangyoulu e
left outer join dept_xiangyoulu d on e.deptno=d.deptno
where e.sal=(select max(sal) from emp_xiangyoulu);
15:查看每个部门的最高工资的员工名字
select e.ename,e.sal,e.deptno from emp_xiangyoulu e join(
select max(sal) max_sal,deptno from emp_xiangyoulu group by deptno)d
on e.deptno=d.deptno and e.sal=d.max_sal;
16:查看有下属的员工信息
select distinct m.* from emp_xiangyoulu e join emp_xiangyoulu m on e.mgr=m.empno;
select * from emp_xiangyoulu where empno in(
select m.empno from emp_xiangyoulu e join emp_xiangyoulu m on e.mgr=m.empno);