mysql练习（含答案）

DROP DATABASE IF EXISTS test1;
CREATE DATABASE test1;
USE test1;

##部门表
#DROP IF EXISTS TABLE DEPT;
CREATE TABLE DEPT(
  DEPTNO int  PRIMARY KEY,##部门编号
  DNAME VARCHAR(14) ,  ##部门名称
  LOC VARCHAR(13)    ##部门地址
  ) ;

INSERT INTO DEPT VALUES  (10,'ACCOUNTING','NEW YORK');
INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS');
INSERT INTO DEPT VALUES  (30,'SALES','CHICAGO');
INSERT INTO DEPT VALUES  (40,'OPERATIONS','BOSTON');
  
##员工表  
#DROP IF EXISTS TABLE EMP;
CREATE TABLE EMP(
  EMPNO int  PRIMARY KEY,  #员工编号
  ENAME VARCHAR(10),  #员工姓名
  JOB VARCHAR(9),    #员工工作
  MGR int,     #员工直属领导编号
  HIREDATE DATE,     #入职时间
  SAL double,    #工资
  COMM double,    #奖金
  DEPTNO int    #对应dept表的外键
);  
## 添加 部门 和 员工 之间的主外键关系
ALTER TABLE EMP ADD CONSTRAINT FOREIGN KEY EMP(DEPTNO) REFERENCES DEPT (DEPTNO);
INSERT INTO EMP VALUES(7369,'SMITH','CLERK',7902,"1980-12-17",800,NULL,20);
INSERT INTO EMP VALUES(7499,'ALLEN','SALESMAN',7698,'1981-02-20',1600,300,30);
INSERT INTO EMP VALUES(7521,'WARD','SALESMAN',7698,'1981-02-22',1250,500,30);
INSERT INTO EMP VALUES(7566,'JONES','MANAGER',7839,'1981-04-02',2975,NULL,20);
INSERT INTO EMP VALUES(7654,'MARTIN','SALESMAN',7698,'1981-09-28',1250,1400,30);
INSERT INTO EMP VALUES(7698,'BLAKE','MANAGER',7839,'1981-05-01',2850,NULL,30);
INSERT INTO EMP VALUES(7782,'CLARK','MANAGER',7839,'1981-06-09',2450,NULL,10);
INSERT INTO EMP VALUES(7788,'SCOTT','ANALYST',7566,'1987-07-03',3000,NULL,20);
INSERT INTO EMP VALUES(7839,'KING','PRESIDENT',NULL,'1981-11-17',5000,NULL,10);
INSERT INTO EMP VALUES(7844,'TURNER','SALESMAN',7698,'1981-09-08',1500,0,30);
INSERT INTO EMP VALUES(7876,'ADAMS','CLERK',7788,'1987-07-13',1100,NULL,20);
INSERT INTO EMP VALUES(7900,'JAMES','CLERK',7698,'1981-12-03',950,NULL,30);
INSERT INTO EMP VALUES(7902,'FORD','ANALYST',7566,'1981-12-03',3000,NULL,20);
INSERT INTO EMP VALUES(7934,'MILLER','CLERK',7782,'1981-01-23',1300,NULL,10);

#工资等级表
#DROP IF EXISTS TABLE SALGRADE;
CREATE TABLE SALGRADE( 
  GRADE int,  #等级
  LOSAL double,  #最低工资
  HISAL double );  #最高工资

INSERT INTO SALGRADE VALUES (1,700,1200);
INSERT INTO SALGRADE VALUES (2,1201,1400);
INSERT INTO SALGRADE VALUES (3,1401,2000);
INSERT INTO SALGRADE VALUES (4,2001,3000);
INSERT INTO SALGRADE VALUES (5,3001,9999);

#1、查找部门30中员工的详细信息。
select * from emp where deptno = 30;

#2、找出从事clerk工作的员工的编号、姓名、部门号。
select empno,ename,deptno from emp where job = 'clerk';

#3、检索出奖金多于基本工资的员工信息。
select * from emp where comm > sal;

#4、检索出奖金多于基本工资60%的员工信息。
select * from emp where comm > sal * 0.6;

#5、找出10部门的经理、20部门的职员 的员工信息。
select * from emp where deptno = 10 and job='MANAGER' or deptno = 20 and job = 'CLERK';

#6、找出10部门的经理、20部门的职员 或者既不是经理也不是职员但是工资高于2000元的员工信息。
select * from emp 
  where deptno = 10 and job='MANAGER' 
     or deptno = 20 and job = 'CLERK'
     or job!='MANAGER' and job != 'CLERK' and sal > 2000 ;
## job not in ('MANAGER','CLERK')

#7、找出获得奖金的员工的工作。
select * from emp where comm > 0;

#8、找出奖金少于100或者没有获得奖金的员工的信息。
select * from emp where comm < 100 or comm is null;

#9、找出姓名以A、B、S开始的员工信息。
select * from emp where ename like 'A%' or ename like 'B%' or ename like 'S%';

#10、找到名字长度为6个字符的员工信息。
select * from emp where length(ename) = 6;
#select * from emp where ename like '______';

#11、名字中不包含R字符的员工信息。
select * from emp where ename not like '%R%';

#12、返回员工的详细信息并按姓名排序。
select * from emp order by ename asc;

#13、返回员工的信息并按工作降序工资升序排列。
select * from emp order by job desc , sal asc;

#14、计算员工的日薪(按30天)。
select ename,sal/30 as '日薪' from emp;
select ename,truncate(sal/30,2) '日薪' from emp;

#15、找出姓名中包含A的员工信息。
select * from emp where ename like '%A%';

#1、返回拥有员工的部门名、部门号。
select distinct d.dname, d.deptno from dept d,emp e where d.deptno = e.deptno;

#2、工资水平多于smith的员工信息。
select *from emp where sal > (select sal from emp where ename = 'smith');
  
#3、返回员工和所属经理的姓名。
select e.ename,m.ename from emp e
  left outer join emp m on e.mgr = m.empno;
select e.ename ,(select m.ename from emp m where m.empno  = e.mgr) ename from emp e;
select e.ename , m.ename from emp e , emp m where e.mgr = m.empno;
   
#4、返回雇员的雇佣日期早于其经理雇佣日期的员工及其经理姓名。
select e.ename,m.ename from emp e
inner join emp m on e.mgr = m.empno
where e.hiredate < m.hiredate;

select e.ename,m.ename from emp e,emp m
where e.mgr=m.empno
and e.hiredate < m.hiredate;

#5、返回员工姓名及其所在的部门名称。
select e.ename,d.dname from emp e , dept d where e.deptno = d.deptno;

#6、返回从事clerk工作的员工姓名和所在部门名称。
select e.ename,d.dname 
from emp e , dept d 
where e.deptno = d.deptno and e.job = 'CLERK';

#7、返回部门号及其本部门的最低工资。
select deptno ,min(sal) sal
from emp 
group by deptno

#8、返回销售部(sales)所有员工的姓名。
select e.ename from emp e,dept d
where e.deptno = d.deptno and d.dname = 'sales';

select ename from emp where deptno=(select deptno from dept where dname='sales');

#9、返回工资水平多于平均工资的员工。
select * from emp e
where e.sal > (select avg(sal) from emp);


#10、返回与SCOTT从事相同工作的员工。
select * from emp
where job = (select job from emp where ename = 'scott');

select e1.* from emp e1 , (select empno,job from emp where ename = 'scott') e2
where e1.job = e2.job and e1.empno != e2.empno;


#11、返回与30部门员工工资水平相同的员工姓名与工资。
select ename,sal from emp
where sal in (select sal from emp where deptno = 30);

#12、返回工资高于30部门所有员工工资水平的员工信息。
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);

#13、返回部门号、部门名、部门所在位置及其每个部门的员工总数。  
select dept.deptno,dept.dname,dept.loc,count(emp.deptno) number from dept,emp
where dept.deptno = emp.deptno
group by emp.deptno;

#14、返回员工的姓名、所在部门名及其工资。
select ename,dname,sal from emp ,dept
where emp.deptno = dept.deptno;

#15、返回员工的详细信息。(包括部门名)
select e.* , d.dname from emp e, dept d
where e.deptno = d.deptno;

#16、返回员工工作及其从事此工作的最低工资。
select job , min(sal) sal from emp
group by job 

#17、计算出员工的年薪，并且以年薪排序。
select ename, sal * 12 as ySalary from emp order by ySalary;

#18、返回工资处于第四级别的员工的姓名。
select ename,sal from emp e  ,salgrade s
where e.sal >= s.losal and e.sal <= s.hisal
   and s.grade = 4;

select emp.ename,emp.sal from 
  emp ,(select losal,hisal from salgrade where grade=4) g
  where  emp.sal between g.losal and g.hisal;

#19、返回工资为二等级的职员名字、部门所在地、和二等级的最低工资和最高工资
select ename ,dname ,sal ,losal,hisal from emp,dept,salgrade
where emp.deptno = dept.deptno and grade = 2
    and sal >= losal and sal < hisal;
  

#20.工资等级多于smith的员工信息。
select grade from salgrade s ,emp e
where s.losal < e.sal and s.hisal > e.sal and e.ename = 'smith';

select e.* from emp e, salgrade s 
where s.hisal < e.sal and s.grade = 1;

select e.* from emp e, salgrade s 
where s.hisal < e.sal and s.grade = (select grade from salgrade s ,emp e
where s.losal < e.sal and s.hisal > e.sal and e.ename = 'smith');