MySQL笔试题整理（一）

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原创 2022-05-15 23:51:16 686 阅读 AI 写同款· GEO 优化 ›

mysql笔试题目 1、学生表 1.1、有学生表student和班级表class，写出一条sql语句查询出得分在最高的学生 select `Name`,Score from stu_1 where Score = (select MAX(Score) from stu_1) 1.2、写一条sql语句查询出一班、二班的人数和平均分，并且按照由高到低排序 select COUNT(*),avg(a.Score) from stu_1 as a,class as b where a.C_id = b.ID grou 阅读详情

一、题目参考

mysql经典面试题之学生成绩表 - 年轻人——001 - 博客园

MySQL经典练习题及答案，常用SQL语句练习50题_我疯的博客-优快云博客_mysql50题

找了这两篇文来做题，可是发现一些运行不了，一些又太难了，对于小白的我看不懂呀，所以自己又整理了一遍，发出来巩固巩固，有更方便的解法也希望大佬指点~

二、表格准备

1、学生表Student

2、成绩表SC

3、课程表Course

4、教师表Teacher

--学生表
create table Student(SID varchar(10),Sname nvarchar(10),Sage datetime,Ssex nvarchar(10));
insert into Student values('01' , '赵雷' , '1990-01-01' , '男');
insert into Student values('02' , '钱电' , '1990-12-21' , '男');
insert into Student values('03' , '孙风' , '1990-05-20' , '男');
insert into Student values('04' , '李云' , '1990-08-06' , '男');
insert into Student values('05' , '周梅' , '1991-12-01' , '女');
insert into Student values('06' , '吴兰' , '1992-03-01' , '女');
insert into Student values('07' , '郑竹' , '1989-07-01' , '女');
insert into Student values('08' , '王菊' , '1990-01-20' , '女');


--成绩表
create table SC(SID varchar(10),CID varchar(10),score decimal(18,1));
insert into SC values('01' , '01' , 80);
insert into SC values('01' , '02' , 90);
insert into SC values('01' , '03' , 99);
insert into SC values('02' , '01' , 70);
insert into SC values('02' , '02' , 60);
insert into SC values('02' , '03' , 80);
insert into SC values('03' , '01' , 80);
insert into SC values('03' , '02' , 80);
insert into SC values('03' , '03' , 80);
insert into SC values('04' , '01' , 50);
insert into SC values('04' , '02' , 30);
insert into SC values('04' , '03' , 20);
insert into SC values('05' , '01' , 76);
insert into SC values('05' , '02' , 87);
insert into SC values('06' , '01' , 31);
insert into SC values('06' , '03' , 34);
insert into SC values('07' , '02' , 89);
insert into SC values('07' , '03' , 98);


--课程表
create table Course(CID varchar(10),Cname nvarchar(10),TID varchar(10));
insert into Course values('01' , '语文' , '02');
insert into Course values('02' , '数学' , '01');
insert into Course values('03' , '英语' , '03');


--教师表
create table Teacher(TID varchar(10),Tname nvarchar(10));
insert into Teacher values('01' , '张三');
insert into Teacher values('02' , '李四');
insert into Teacher values('03' , '王五');

三、题目

题目的序号是按照参考的2篇文章来的，如果想对比可以翻看

我是用的navicat

-- 1、查询"01"课程比"02"课程成绩高的学生的信息及课程分数

-- 1.1、查询同时存在"01"课程和"02"课程的情况
select a.*,b.score 01_sc,c.score 02_sc from Student a,SC b,SC c 
where a.SID=b.SID and a.SID=c.SID and b.CID='01' and c.CID='02' and b.score>c.score;


-- 1.2、查询同时存在"01"课程和"02"课程的情况和存在"01"课程但可能不存在"02"课程的情况
select a.*,b.score 01_sc,c.score 02_sc from Student a
left join SC b on a.SID=b.SID and b.CID='01'
left join SC c on a.SID=c.SID and c.CID='02'
where b.score>IFNULL(c.score,0);




-- 2、查询"01"课程比"02"课程成绩低的学生的信息及课程分数

-- 2.1、查询同时存在"01"课程和"02"课程的情况
select a.*,b.score,c.score from Student a,SC b,SC c
where a.SID=b.SID and a.SID=c.SID and b.CID='01' and c.CID='02' and b.score<c.score;


-- 2.2、查询同时存在"01"课程和"02"课程的情况和不存在"01"课程但存在"02"课程的情况
select a.*,b.score,c.score from Student a
left join SC b on a.SID=b.SID and b.CID='01'
left join SC c on a.SID=c.SID and c.CID='02'
where c.score>IFNULL(b.score,0);




-- 3、查询平均成绩大于等于60分的同学的学生编号和学生姓名和平均成绩
select a.SID,a.Sname,avg(b.score) from Student a
left join SC b on a.SID=b.SID group by a.SID,a.Sname having avg(b.score)>=60;




-- 4、查询平均成绩小于60分的同学的学生编号和学生姓名和平均成绩
select a.SID,a.Sname,avg(b.score) from Student a 
left join SC b on a.SID=b.SID group by a.SID,a.Sname 
having IFNULL(avg(b.score),0)<60;




-- 5、查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩
select a.SID,a.Sname,count(*),sum(b.score) from Student a
left join SC b on a.SID=b.SID group by a.SID,a.Sname;




-- 6、查询"李"姓老师的数量
SELECT count(*) from Teacher where Tname like '李%';




-- 7、查询学过"张三"老师授课的同学的信息
SELECT a.* from Student a,Course b,SC c,Teacher d 
where a.SID=c.SID and b.CID=c.CID and b.TID=d.TID and d.Tname='张三';




-- 8、查询没学过"张三"老师授课的同学的信息
SELECT a.* from Student a where a.SID not in
(SELECT a.SID from Student a,Course b,SC c,Teacher d 
where a.SID=c.SID and b.CID=c.CID and b.TID=d.TID and d.Tname='张三');




-- 9、查询学过编号为"01"并且也学过编号为"02"的课程的同学的信息
select a.* from Student a,SC b,SC c 
where a.SID=b.SID and a.SID=c.SID and b.CID='01' and c.CID='02';




-- 10、查询学过编号为"01"但是没有学过编号为"02"的课程的同学的信息
select * from Student left join SC on Student.SID=SC.SID
where SC.CID='01' and Student.Sname not in
(SELECT Student.Sname from Student,SC where Student.SID=SC.SID and SC.CID='02');




-- 11、查询没有学全所有课程的同学的信息
select Student.* from Student left join SC on Student.SID=SC.SID
group by Student.SID having count(CID)<(SELECT count(CID) from Course);




-- 12、查询至少有一门课与学号为"01"的同学所学相同的同学的信息
select distinct Student.* from Student,SC where Student.SID=SC.SID and CID in 
(select CID from SC where SID='01') and Student.SID!='01';




-- 13、查询和"01"号的同学学习的课程完全相同的其他同学的信息
select Student.* from Student,SC where Student.SID=SC.SID and SC.SID!='01' 
and CID in (select CID from SC where SID='01')
group by SC.SID having count(CID) = (select count(CID) from SC where SID='01');




-- 15、查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩
select a.SID,a.Sname,avg(score) from Student a,SC where a.SID=SC.SID and a.SID in 
(select SID from SC where score<60 GROUP BY SID HAVING count(CID)>=2)
group by a.SID,a.Sname;




-- 16、检索"01"课程分数小于60，按分数降序排列的学生信息
select Student.* from Student INNER JOIN SC on Student.SID=SC.SID
where CID='01' and score<60 ORDER BY score DESC;




-- 17、按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩
select a.Sname,d.Cname,b.score,c.avg from Student a,SC b,Course d,
(select Sname,avg(score) avg from Student inner join SC on Student.SID=SC.SID
GROUP BY Sname) c where a.SID=b.SID and a.Sname=c.Sname and b.CID=d.CID
ORDER BY c.avg DESC;




-- 18、查询各科成绩最高分、最低分和平均分：
以如下形式显示：课程ID，课程name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率
-- --及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90

SELECT b.CID 课程编号,b.Cname 课程名称,
max(score) 最高分,min(score) 最低分,avg(score) 平均分,
(select count(*) from SC where CID=b.CID and score>=60)/
(select count(*) from SC where CID=b.CID)及格率,
(select count(*) from SC where CID=b.CID and score >=70 and score <80)/
(select count(*) from SC where CID=b.CID)中等率,
(select count(*) from SC where CID=b.CID and score >=80 and score <90)/
(select count(*) from SC where CID=b.CID)优良率,
(select count(*) from SC where CID=b.CID and score>=90)/
(select count(*) from SC where CID=b.CID)优秀率
from SC a,Course b where a.CID=b.CID GROUP BY b.CID,b.Cname;




-- 19、按各科成绩进行排序
SELECT a.Cname,b.Sname,c.score from Course a,Student b,SC c
where a.CID=c.CID and b.SID=c.SID
order by a.Cname,c.score desc;




-- 20、查询学生的总成绩并进行排名
select Student.Sname,ifnull(SUM(score),0) from Student
left join SC on Student.SID=SC.SID 
group by Student.Sname order by sum(score) desc;

-- 21、查询不同老师所教不同课程平均分从高到低显示
select a.*,b.CID,b.Cname,avg(score)from Teacher a,Course b,SC c
where a.TID=b.TID and b.CID=c.CID
GROUP BY a.TID,b.CID ORDER BY avg(score) desc;




-- 25、查询各科成绩前三名的记录
--考虑同分成绩并列的情况
select a.* from SC a 
left join (select distinct CID,score from SC) b  
on a.CID=b.CID and a.score<b.score
group by a.SID,a.CID,a.score HAVING COUNT(1)<3
ORDER BY a.CID,a.score DESC;




-- 26、查询每门课程被选修的学生数
select CID,count(SID) from SC GROUP BY CID;




-- 27、查询出只有两门课程的全部学生的学号和姓名
select a.SID,a.Sname from Student a,SC b where a.SID=b.SID 
group by a.SID,a.Sname having count(*)=2;




-- 28、查询男生、女生人数
select Ssex,count(*) from Student GROUP BY Ssex;




-- 29、查询名字中含有"风"字的学生信息
select * from Student where Sname like '%风%';




-- 30、查询同名同姓学生名单，并统计同名人数
select Sname,count(*) from Student GROUP BY Sname having count(*)>1;




-- 31、查询1990年出生的学生名单(注：Student表中Sage列的类型是datetime)
SELECT * from Student where Sage like '%1990%';

SELECT * from Student where YEAR(Sage)='1990';




-- 32、查询每门课程的平均成绩，结果按平均成绩降序排列，平均成绩相同时，按课程编号升序排列
select a.CID,a.Cname,avg(score) from Course a,SC b where a.CID=b.CID 
group by a.Cname,a.CID order by avg(score) desc,a.CID;




-- 33、查询平均成绩大于等于85的所有学生的学号、姓名和平均成绩
select a.SID,a.Sname,avg(score) from Student a,SC where a.SID=SC.SID
GROUP BY a.SID,a.Sname HAVING avg(score)>=85;




-- 34、查询课程名称为"数学"，且分数低于60的学生姓名和分数
select a.Sname,b.score from Student a,SC b,Course c
where a.SID=b.SID and b.CID=c.CID and c.Cname='数学' and b.score<60;




-- 35、查询所有学生的课程及分数情况
-- 可以显示出没有成绩的学生信息
select a.Sname,c.Cname,b.score from Student a
LEFT JOIN SC b on a.SID=b.SID
LEFT JOIN Course c on b.CID=c.CID
ORDER BY a.SID;




-- 36、查询任何一门课程成绩在70分以上的姓名、课程名称和分数
select a.Sname,c.Cname,b.score from Student a
LEFT JOIN SC b on a.SID=b.SID
LEFT JOIN Course c on b.CID=c.CID
where b.score>=70 ORDER BY a.SID;




-- 37、查询不及格课程的学生信息
select a.Sname,c.Cname,b.score from Student a 
left join SC b on a.SID=b.SID 
left join Course c on b.CID=c.CID 
where b.score<60 or b.score is null;




-- 38、查询课程编号为01且课程成绩在80分以上的学生的学号和姓名
select a.SID,a.Sname,b.score from Student a,SC b 
where a.SID=b.SID and b.CID='01' and b.score>=80;



 
-- 39、求每门课程的学生人数
select SC.CID,Course.Cname,count(*) from SC,Course 
where SC.CID=Course.CID group by SC.CID,Course.Cname;




-- 40、查询选修"张三"老师所授课程的学生中，成绩最高的学生信息及其成绩

-- --最高分只有一个时
select a.*,b.score from Student a,SC b,Course c,Teacher d
where a.SID=b.SID and b.CID=c.CID and c.TID=d.TID and d.Tname='张三'
order by b.score desc limit 1;


-- --最高分有多个时
select a.*,b.score from Student a,SC b,Course c,Teacher d
where a.SID=b.SID and b.CID=c.CID and c.TID=d.TID and d.Tname='张三' and b.score=
(select max(score) from SC,Course,Teacher where SC.CID=Course.CID and 
Course.TID=Teacher.TID and Teacher.Tname='张三');




-- 42、查询每门课程成绩最好的前两名
--考虑同分成绩并列的情况
select * from SC a
where (select COUNT(distinct b.score) from SC b 
where b.CID=a.CID and b.score>=a.score)<=2 
ORDER BY a.CID;




-- 43、统计每门课程的学生选修人数（超过5人的课程才统计）
要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列
select b.CID,count(*) from Student a,SC b where a.SID=b.SID group by b.CID 
having count(*)>5 order by count(*) desc,CID;



 
-- 44、检索至少选修两门课程的学生学号
select Student.SID from Student,SC where Student.SID=SC.SID 
group by Student.SID having count(CID)>=2;




-- 45、查询选修了全部课程的学生信息
select a.SID,a.Sname,count(*) from Student a,SC b where a.SID=b.SID 
group by a.SID,a.Sname 
having count(*)=(select count(*) from Course);

select * from Student where SID in
(select SID from SC group by SID having count(1) = (select count(1) from Course));




-- 46、查询各学生的年龄
select *,TIMESTAMPDIFF(year,Sage,CURDATE()) from Student;




-- 49、查询本月过生日的学生
select * from Student where MONTH(Sage)=MONTH(CURDATE());




-- 50、查询下月过生日的学生
select * from Student where MONTH(Sage)=MONTH(CURDATE())+1;




-- 补充：找出平均分最低的学生和分数

-- --平均分只有一个时
select a.SID,a.Sname,avg(score) pj from Student a,SC b 
where a.SID=b.SID group by a.SID,a.Sname order by pj limit 1;


-- --平均分有多个时
select a.SID,a.Sname,avg(score) pj from Student a,SC b where a.SID=b.SID 
group by a.SID,a.Sname
having pj=(select avg(score) from SC group by SID order by avg(score) limit 1);

太难的题就没有写了，有兴趣的可以去看参考的文章

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