emp员工表
(empno员工号/ename员工姓名/job工作/mgr上级编号/hiredate受雇日期/sal薪金/comm佣金/deptno部门编号)
------1.选择部门30中的所有员工.
select ename
from emp
where deptno = 30;
------2.列出所有办事员(CLERK)的姓名，编号和部门编号.
select ename,empno,deptno
from emp
where job='CLERK';
------3.找出佣金高于薪金的员工.
select *
from emp
where nvl(comm,0)>sal;
------4.找出佣金高于薪金的60%的员工.
select *
from emp
where nvl(comm,0)>sal*0.6;
------5.找出部门10中所有经理(MANAGER)和部门20中所有办事员(CLERK)的详细资料
select *
from emp
where deptno=10 and job ='manager'
or deptno=20 and job ='CLERK';
------6.找出部门10中所有经理(MANAGER),部门20中所有办事员(CLERK),既不是经理又不是办事员但其薪金大于或等于2000的所有员工的详细资料.
select *
from emp
where deptno=10 and job ='manager'
or deptno=20 and job ='CLERK'
or deptno not in ('manager','CLERK') and sal >=2000;
------7.找出收取佣金的员工的不同工作.
select distinct job
from emp
where comm>0;
------8.找出不收取佣金或收取的佣金低于100的员工.
select *
from emp
where sal between 0 and 100
or sal is null;
------9.找出各月倒数第3天受雇的所有员工.
select *
from emp
where hiredate=last_day(hiredate)-2;
------10.找出早于12年前受雇的员工.
select *
from emp
where hiredate<add_months(sysdate,-12*12);
------11.以首字母大写的方式显示所有员工的姓名.
select initcap(ename)
from emp;
------12.显示正好为5个字符的员工的姓名.
select *
from emp
where ename like '_____';
------13.显示不带有"R"的员工的姓名.
select initcap(ename)
from emp;
where ename not like '%R%';
------14.显示所有员工姓名的前三个字符
select substr(ename,1,3)
from emp
------15.显示所有员工的姓名,用a替换所有"A"
select translate(ename,'A','a')
from emp;
------16.显示满10年服务年限的员工的姓名和受雇日期.
select ename,hiredate
from emp
where hiredate>add_months(sysdate,-12*10);
------17.显示员工的详细资料,按姓名排序.
select *
from emp
order by ename;
------18.显示员工的
