MySQL面试题
1、取得每个部门最高薪水的人员的名称
select ename from emp e,(
select deptno,max(sal) max_sal from emp group by deptno
) each_dept_max_sal
where e.deptno=each_dept_max_sal.deptno and
e.sal=each_dept_max_sal.max_sal;2、哪些人的薪水在部门的平均薪水之上
select ename,sal from emp e,(
select deptno,avg(sal) avg_sal from emp group by deptno
) d where e.deptno=d.deptno and
e.sal>d.avg_sal;3、取得部门中（所有有人的）评价薪水等级
select ename,grade from emp e,salgrade s
where e.sal between s.losal and s.hisal;4、不准用组函数（max），取得最高薪水
select sal from emp order by sal desc limit 0,1;5、取得平均薪水最高的部门的部门编号（至少给出两种解决方案）
select deptno from emp group by deptno order by avg(sal) desc limit 0,1;select deptno from emp group by deptno having avg(sal) = (
select max(avg_sal) from (
select avg(sal) avg_sal from emp group by deptno
) d
);6、取得平均薪水最高的部门的部门名称
select dname from dept where deptno =(
select deptno from emp group by deptno order by avg(sal) desc limit 0,1
);7、求平均薪水的等级最低的部门的部门名称
select dname from dept where deptno =(
select deptno from emp group by deptno order by avg(sal) limit 0,1
);8、取得比普通员工（员工代码没有在mgr字段上出现的）的最高薪水还要高的领导人姓名
select ename,sal from emp where empno in(
select ifnull(mgr,0) mgr from emp
) and sal > (
select max(sal) from emp where empno not in (
select ifnull(mgr,0) mgr from emp
)
);9、取得薪水最高的前五名员工
select ename,sal from emp order by sal desc limit 0,5;10、取得薪水最高的第六到第十名员工
select ename,sal from emp order by sal desc limit 5,5;11、取得最后入职的五名员工
select ename,hiredate from emp order by hiredate desc limit 0,5;12、取得每个薪水等级有多少员工
select grade,count(ename) from (
select ename,grade from emp e,salgrade s
where e.sal between s.losal and s.hisal
) t group by grade;13、使用资料2的题：
有三个表，表S（学生表），C（课程表），SC（学生选课表）
S（SNO，SNAME）代表（学号，姓名）
C（CNO,CNAME,CTEACHER）代表（课号，课名，老师）
SC（SNO,CNO,SCGRADE）代表（学号，课号，成绩）
问题：
1.找出没有选过’‘黎明’'老师的所有学生姓名
select sname from s where sno not in(
select sno from s where sno in(
select sno from sc where cno in(
select cno from c where cteacher='黎明'
)
)
);2.列出2门以上（含2门）不及格学生姓名及平均成绩
select sname,sc.avg_scgrade from s,(
select sno,avg(scgrade) avg_scgrade from sc where scgrade<60 group by sno
having count(cno)>=2
) sc where s.sno=sc.sno;3.既学过1号课程又学过2号课程的所有的学生姓名
select sname from s where sno in (
select sc1.sno from sc sc1,sc sc2 where sc1.sno=sc2.sno
and sc1.cno=1 and sc2.cno=2
);14、列出所有员工及领导的名字
select e1.ename 员工,e2.ename 领导 from emp e1 left join emp e2
on e1.mgr=e2.empno;15、列出受雇日期早于其直接上级的所有员工的编号姓名
select e1.ename 员工,e2.ename 领导 from emp e1, emp e2
where e1.mgr=e2.empno and e1.hiredate16、列出部门名称和这些部门的员工信息，同时列出那些没有员工的部门
select dname,e.* from dept d left join emp e on e.deptno=d.deptno;17、列出只是有5个员工的所有部门
select d.deptno from dept d,emp e
where e.deptno=d.deptno
group by d.deptno
having count(empno)>=5;18、列出薪水比"SMITH"多的所有员工的信息
select ename,sal from emp where ename!='SMITH' and sal > (
select sal from emp where ename='SMITH'
);19、列出所有"CLERK"（办事员）的姓名及其部门名称，部门的人数
select ename,dname,count from emp e,dept d,(
select deptno,count(empno) count from emp
group by deptno
) c
where e.deptno=d.deptno and d.deptno=c.deptno and JOB='CLERK';20、列出最低薪水大于1500的各种工作及从事此工作的全部雇员人数
select job,count(empno) count from emp group by job having min(sal)>1500;21、列出在部门"SALES"（销售部）工作的员工的姓名，假设不知道销售部的部门编号
select ename from emp where deptno =(
select deptno from dept where dname='SALES'
);22、列出薪水高于公司平均薪水的所有员工，所在部门，上级领导，雇员的工资等级
select e.ename,dname,m.ename mgr_ename,grade from
emp e left join emp m on e.mgr=m.empno
join dept d on e.deptno=d.deptno
join salgrade s on e.sal between s.losal and s.hisal
where e.sal > (
select avg(sal) avg_sal from emp
);23、列出与"SCOTT"从事相同工作的所有员工及部门名称
select ename,dname from emp e,dept d where e.deptno=d.deptno and ename!='SCOTT'
and job in (
select job from emp where ename='SCOTT'
);24、列出薪水等于部门30中员工的薪水的其他员工的姓名和薪水
select ename,sal from emp where deptno!=30 and sal in (
select distinct sal from emp where deptno=30
);25、列出薪水高于在部门30工作的所有员工的薪水的员工的姓名和薪水及部门名
select ename,sal,dname from emp e,dept d
where e.deptno=d.deptno and sal > all(
select distinct sal from emp where deptno=30
);26、列出在每个部门工作的员工数量，平均工作和平均服务期限，没有员工的部门，部门人数是0
select d.deptno,count(empno) count,ifnull(avg(sal),0) avg_sal,
TimeStampDiff(YEAR,ifnull(hiredate,now()),now()) avg_time
from dept d left join emp e on e.deptno=d.deptno
group by d.deptno;27、列出所有员工的姓名、部门名称和工资
select ename,dname,sal from emp e left join dept d
on e.deptno=d.deptno;28、列出所有部门的详细信息和人数
select d.*,ifnull(temp.count,0) 人数 from dept d left join (
select deptno,count(empno) count from emp group by deptno
) temp on d.deptno=temp.deptno;29、列出各种工作的最低工资及从事此工作的雇员名称
select e.* from emp e,(
select job,min(sal) min_sal from emp group by job
) j where e.job=j.job and e.sal=j.min_sal;30、列出各个部门的MANAGER（领导）的最低薪水
select deptno,min(sal) from emp where empno in (
select mgr from emp
) group by deptno;31、列出所有员工的年工资，按年薪从低到高排序
select ename,sal*12+ifnull(comm,0) year_sal from emp order by year_sal;32、求出员工领导的薪水超过3000的员工名称和领导名称
select e.ename,m.ename from emp e,(
select empno,ename from emp where empno in (
select mgr from emp
) and sal > 3000
) m where e.mgr=m.empno;33、求出部门名称中，带'S'字符的部门员工的工资合计、部门人数
select dname,ifnull(sum(sal),0) sum_sal,count(empno) from dept d left join emp e
on e.deptno=d.deptno where dname like '%S%'
group by dname;34、给任职日期超过30年的员工加薪10%
update emp set sal=sal+sal*0.1 where TimeStampDiff(YEAR,ifnull(hiredate,now()),now())>30;资料1：
DROP TABLE IF EXISTS EMP;
DROP TABLE IF EXISTS DEPT;
DROP TABLE IF EXISTS SALGRADE;
CREATE TABLE DEPT
(DEPTNO int(2) not null ,
DNAME VARCHAR(14) ,
LOC VARCHAR(13),
primary key (DEPTNO)
);
CREATE TABLE EMP
(EMPNO int(4) not null ,
ENAME VARCHAR(10),
JOB VARCHAR(9),
MGR INT(4),
HIREDATE DATE DEFAULT NULL,
SAL DOUBLE(7,2),
COMM DOUBLE(7,2),
primary key (EMPNO),
DEPTNO INT(2)
)
;
CREATE TABLE SALGRADE
( GRADE INT,
LOSAL INT,
HISAL INT );
INSERT INTO DEPT ( DEPTNO, DNAME, LOC ) VALUES (
10, 'ACCOUNTING', 'NEW YORK');
INSERT INTO DEPT ( DEPTNO, DNAME, LOC ) VALUES (
20, 'RESEARCH', 'DALLAS');
INSERT INTO DEPT ( DEPTNO, DNAME, LOC ) VALUES (
30, 'SALES', 'CHICAGO');
INSERT INTO DEPT ( DEPTNO, DNAME, LOC ) VALUES (
40, 'OPERATIONS', 'BOSTON');
commit;
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7369, 'SMITH', 'CLERK', 7902, '1980-12-17'
, 800, NULL, 20);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7499, 'ALLEN', 'SALESMAN', 7698, '1981-02-20'
, 1600, 300, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7521, 'WARD', 'SALESMAN', 7698, '1981-02-22'
, 1250, 500, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7566, 'JONES', 'MANAGER', 7839, '1981-04-02'
, 2975, NULL, 20);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7654, 'MARTIN', 'SALESMAN', 7698, '1981-09-28'
, 1250, 1400, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7698, 'BLAKE', 'MANAGER', 7839, '1981-05-01'
, 2850, NULL, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7782, 'CLARK', 'MANAGER', 7839, '1981-06-09'
, 2450, NULL, 10);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7788, 'SCOTT', 'ANALYST', 7566, '1987-04-19'
, 3000, NULL, 20);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7839, 'KING', 'PRESIDENT', NULL, '1981-11-17'
, 5000, NULL, 10);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7844, 'TURNER', 'SALESMAN', 7698, '1981-09-08'
, 1500, 0, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7876, 'ADAMS', 'CLERK', 7788, '1987-05-23'
, 1100, NULL, 20);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7900, 'JAMES', 'CLERK', 7698, '1981-12-03'
, 950, NULL, 30);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7902, 'FORD', 'ANALYST', 7566, '1981-12-03'
, 3000, NULL, 20);
INSERT INTO EMP ( EMPNO, ENAME, JOB, MGR, HIREDATE, SAL, COMM,
DEPTNO ) VALUES (
7934, 'MILLER', 'CLERK', 7782, '1982-01-23'
, 1300, NULL, 10);
commit;
INSERT INTO SALGRADE ( GRADE, LOSAL, HISAL ) VALUES (
1, 700, 1200);
INSERT INTO SALGRADE ( GRADE, LOSAL, HISAL ) VALUES (
2, 1201, 1400);
INSERT INTO SALGRADE ( GRADE, LOSAL, HISAL ) VALUES (
3, 1401, 2000);
INSERT INTO SALGRADE ( GRADE, LOSAL, HISAL ) VALUES (
4, 2001, 3000);
INSERT INTO SALGRADE ( GRADE, LOSAL, HISAL ) VALUES (
5, 3001, 9999);
commit;资料2：
drop table if exists s;
drop table if exists c;
drop table if exists sc;
create table s(
sno int(10) primary key,-- 学号
sname varchar(14)-- 姓名
);
create table c(
cno int(10) primary key,-- 课号
cname varchar(14),-- 课名
cteacher varchar(14)-- 成绩
);
create table sc(
sno int(10),-- 外键，学号
cno int(10),-- 外键，课号
scgrade int(10),-- 成绩
primary key(sno,cno),-- 联合主键
CONSTRAINT sc_s_fk FOREIGN KEY(sno) REFERENCES s(sno),-- 外键约束
CONSTRAINT sc_c_fk FOREIGN KEY(cno) REFERENCES c(cno)-- 外键约束
);
insert into s(sno,sname) values(1,'a');
insert into s(sno,sname) values(2,'b');
insert into s(sno,sname) values(3,'c');
insert into s(sno,sname) values(4,'d');
insert into c(cno,cname,cteacher) values(1,'java','王老师');
insert into c(cno,cname,cteacher) values(2,'C++','张老师');
insert into c(cno,cname,cteacher) values(3,'C#','李老师');
insert into c(cno,cname,cteacher) values(4,'mysql','周老师');
insert into c(cno,cname,cteacher) values(5,'oracle','黎明');
insert into sc(sno,cno,scgrade) values(1,1,50);
insert into sc(sno,cno,scgrade) values(1,2,50);
insert into sc(sno,cno,scgrade) values(1,3,50);
insert into sc(sno,cno,scgrade) values(2,2,80);
insert into sc(sno,cno,scgrade) values(2,3,70);
insert into sc(sno,cno,scgrade) values(2,4,59);
insert into sc(sno,cno,scgrade) values(3,1,60);
insert into sc(sno,cno,scgrade) values(3,2,61);
insert into sc(sno,cno,scgrade) values(3,3,99);
insert into sc(sno,cno,scgrade) values(3,4,100);
insert into sc(sno,cno,scgrade) values(3,5,52);
insert into sc(sno,cno,scgrade) values(4,3,82);
insert into sc(sno,cno,scgrade) values(4,4,99);
insert into sc(sno,cno,scgrade) values(4,5,40);
select * from s;
select * from c;
select * from sc;