Learn SQL | 基础操作综合练习

Posted 2021-02-11 uusystem

一、创建表

• 创建表student，特征包括学生编号、姓名、性别、出生年月及班级。

create table student
(
SNO VARCHAR(3) NOT NULL, 
SNAME VARCHAR(4) NOT NULL,
SSEX VARCHAR(2) NOT NULL,
SBIRTHDAY DATETIME,
CLASS VARCHAR(5)
);

• 创建表course，特征包括课程编号、课程名称和教师编号。

create table course
(
CNO VARCHAR(5) NOT NULL, 
CNAME VARCHAR(10) NOT NULL,
TNO VARCHAR(10) NOT NULL
);

• 创建表score，特征包括学生编号、课程编号与分数。

create table score
( 
SNO VARCHAR(3) NOT NULL, 
CNO VARCHAR(5) NOT NULL, 
DEGREE NUMERIC(10, 1) NOT NULL
);

• 创建表teacher，特征包括教师编号、姓名、性别、出生年月、职称及所属院系。

create table teacher
( 
TNO VARCHAR(3) NOT NULL, 
TNAME VARCHAR(4) NOT NULL, 
TSEX VARCHAR(2) NOT NULL, 
TBIRTHDAY DATETIME NOT NULL, 
PROF VARCHAR(6), 
DEPART VARCHAR(10) NOT NULL
);

---

二、插入表数据

接下来依次向创建好的四张表插入数据，操作如下：

• 向student表插入6条学生信息数据

insert into student (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,‘曾华‘ 
,‘男‘ ,1977-09-01,95033);
insert into student (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,‘匡明‘ 
,‘男‘ ,1975-10-02,95031);
insert into student (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,‘王丽‘ 
,‘女‘ ,1976-01-23,95033);
insert into student (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,‘李军‘ 
,‘男‘ ,1976-02-20,95033);
insert into student (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,‘王芳‘ 
,‘女‘ ,1975-02-10,95031);
insert into student (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,‘陆君‘ 
,‘男‘ ,1974-06-03,95031);

• 向course表插入4条课程数据

insert into course (CNO,CNAME,TNO)VALUES (‘3-105‘ ,‘计算机导论‘,825)
insert into course (CNO,CNAME,TNO)VALUES (‘3-245‘ ,‘操作系统‘ ,804);
insert into course (CNO,CNAME,TNO)VALUES (‘6-166‘ ,‘数据电路‘ ,856);
insert into course (CNO,CNAME,TNO)VALUES (‘9-888‘ ,‘高等数学‘ ,100);

• 向score表插入12条得分数据

insert into score (SNO,CNO,DEGREE)VALUES (103,‘3-245‘,86);
insert into score (SNO,CNO,DEGREE)VALUES (105,‘3-245‘,75);
insert into score (SNO,CNO,DEGREE)VALUES (109,‘3-245‘,68);
insert into score (SNO,CNO,DEGREE)VALUES (103,‘3-105‘,92);
insert into score (SNO,CNO,DEGREE)VALUES (105,‘3-105‘,88);
insert into score (SNO,CNO,DEGREE)VALUES (109,‘3-105‘,76);
insert into score (SNO,CNO,DEGREE)VALUES (101,‘3-105‘,64);
insert into score (SNO,CNO,DEGREE)VALUES (107,‘3-105‘,91);
insert into score (SNO,CNO,DEGREE)VALUES (108,‘3-105‘,78);
insert into score (SNO,CNO,DEGREE)VALUES (101,‘6-166‘,85);
insert into score (SNO,CNO,DEGREE)VALUES (107,‘6-106‘,79);
insert into score (SNO,CNO,DEGREE)VALUES (108,‘6-166‘,81);

• 向teacher表插入4条教师信息数据

insert into teacher (TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 
VALUES (804,‘李诚‘,‘男‘,‘1958-12-02‘,‘副教授‘,‘计算机系‘);
insert into teacher (TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 
VALUES (856,‘张旭‘,‘男‘,‘1969-03-12‘,‘讲师‘,‘电子工程系‘);
insert into teacher (TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART)
VALUES (825,‘王萍‘,‘女‘,‘1972-05-05‘,‘助教‘,‘计算机系‘);
insert into teacher (TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) 
VALUES (831,‘刘冰‘,‘女‘,‘1977-08-14‘,‘助教‘,‘电子工程系‘);

---

三、题目

1. 查询Student表中的所有记录的sname、ssex和class列

select sname,ssex,class from student;

2. 查询教师所有的单位（即不重复的depart列）

select distinct depart from teacher;

3. 查询student表的所有记录

select * from student;

4. 查询score表中成绩在60到80之间的所有记录

select * from score where degree between 60 and 80;

5. 查询score表中成绩为85，86或88的记录

select * from score where degree in (85,86,88);

6. 查询student表中"95031"班或性别为"女"的同学记录

select * from student where class = ‘95031‘ or ssex = ‘女‘;

7. 以class降序查询student表的所有记录
8. 以cno升序、degree降序查询score表的所有记录

select * from student order by class desc;
select * from score order by cno asc,degree desc;

9. 查询"95031"班的学生人数

select count(*) from student where class = ‘95031‘;  

10. 查询score表中的最高分的学生学号和课程号

select sno,cno from score where degree in (
select max(degree) from score
);

11. 查询"3-105"号课程的平均分

select avg(degree) from score where cno = ‘3-105‘;

12. 查询score表中至少有5名学生选修的并以3开头的课程的平均分数

select avg(degree) from score 
where cno like ‘3%‘ 
group by cno having count(*) >= 5;

13. 查询最低分大于70，最高分小于90的sno列

select sno from score 
group by sno 
having min(degree) > 70 and max(degree) < 90;

14. 查询所有学生的sname、cno和degree列
15. 查询所有学生的sno、cname和degree列
16. 查询所有学生的sname、cname和degree列

# 14
select a.sname,b.cno,b.degree from student as a 
join score as b on a.sno = b.sno
# 15
select a.cname,b.sno,b.degree from course as a
join score as b on a.cno = b.cno
# 16
select a.sname,b.cname,c.degree from student as a
join course as b
join score as c
on a.sno = c.sno and b.cno = c.cno;
# 第二种解法
select a.sname,b.cname,c.degree from student as a
join (course b,score c)
on a.sno = c.sno and b.cno = c.cno;

17. 查询"95033"班所选课程的平均分

select avg(degree) from score 
where sno in (
select sno from student where class = ‘95033‘
);
# 进阶解法
select avg(a.degree) from score a
join student b 
on a.sno = b.sno where b.class = ‘95033‘;

18. 假设使用如下命令建立了一个grade表，现查询所有同学的Sno、Cno和rank列，并按照rank列排序

create table grade
(
low numeric(3,0),
upp numeric(3,0),
rank char(1)
);
insert into grade values (90,100,‘A‘);
insert into grade values (80,89,‘B‘);
insert into grade values (70,79,‘C‘);
insert into grade values (60,69,‘D‘);
insert into grade values (0,59,‘E‘);

解法如下：

select a.sno,a.cno,b.rank from score a 
join grade b 
where a.degree between b.low and b.upp
order by rank;

19. 查询score表中选修"3-105"课程的成绩高于"109"号同学成绩的所有同学的记录

# 解法一
select * from score where cno = ‘3-105‘
and degree > (
select degree from score where sno = 109 and cno = ‘3-105‘
);
# 解法二
select a.* from score a 
where a.cno = ‘3-105‘ and a.degree > all(select degree from score b 
where b.sno = ‘109‘ and b.cno = ‘3-105‘);

20. 查询score中选学一门以上课程的同学中分数为非最高分成绩的记录

select A.sno from score as A where A.degree not in (
select max(B.degree) from score as B group by B.sno )
group by A.sno
having count(A.sno) > 1;

21. 查询和学号为107的同学同年出生的所有学生的sno、sname和sbirthday列

考察日期与时间函数的运用

select sno,sname,sbirthday from student where year(sbirthday) in 
(
select year(sbirthday) from student wehre sno = 107
);

22. 查询"张旭"教师任课的学生成绩

select degree from score where cno in (
select cno from course where tno in (
select tno from teacher where teacher = ‘张旭‘));
# 进阶解法
select a.degree from score a 
join (teacher b,course c)
on a.cno = c.cno and b.tno = c.tno
where b.tname = ‘张旭‘;

23. 查询选修某课程的同学人数多于5人的教师姓名

select a.tname from teacher a 
join(course b,score c)
on a.tno = b.tno and b.cno = c.cno
group by c.cno having count(*) > 5;

24. 查询所有表中关于"95033"班和"95031"班全体学生的信息记录

select * from student a inner join score b 
on a.sno = b.sno inner join course c
on b.cno = c.cno inner join teacher d
on c.tno = d.tno 
where a.class = ‘95033‘ or a.class = ‘95031‘;

25. 查询存在有85分以上成绩的课程cno

# 解法一：
select distinct cno from score where degree > 85;
# 解法二：
select cno from score group by cno having max(degree) >85;

26. 查询出"计算机系"教师所教课程的成绩表

select a.*,b.cname,c.tname,c.depart from score a
join (course b, teacher c)
on a.cno = b.cno and b.tno = c.tno
where c.depart = ‘计算机系‘;

27. 查询"计算机系"中与"电子工程系"没有相同职称的教师的tname和prof

select tname,prof from teacher where depart = ‘计算机系‘ and prof not in
(select prof from teacher where depart = ‘电子工程系‘);

28. 查询选修编号为"3-105"课程且成绩高于选修编号为"3-245"的同学的cno、sno和degree,并按degree从高到低次序排序。

select * from score as a,score as b
where a.cno = ‘3-105‘ and b.cno = ‘3-245‘
and a.sno = b.sno
and a.degree > b.degree
order by a.degree desc;

29. 查询所有教师和同学的name、sex和birthday
30. 查询所有女教师和女同学的name、sex和birthday

# 29
select sname as name, ssex as sex, sbirthday as birthday from student
union
select tname as name, tsex as sex, tbirthday as birthday from teacher;
# 30
select sname as name, ssex as sex, sbirthday as birthday from student
where ssex = ‘女‘
union
select tname as name, tsex as sex, tbirthday as birthday from teacher
where tsex = ‘女‘;

31. 查询成绩比该课程平均成绩低的同学的成绩表

select a.* from score a where degree < (
select avg(degree) from score b 
where a.cno = b.cno );

32. 查询所有任课教师的tname和depart
33. 查询所有未讲课的教师的tname和depart

# 32
# 解法一
select a.tname,a.depart from teacher a 
join course b 
on a.tno = b.tno;
# 解法二
select a.tname,a.depart from teacher a
where exists (
select * from course b where a.tno = b.tno
);
# 33
select a.tname,a.depart from teacher a
where not exists (
select * from course b where a.tno = b.tno
);

34. 查询至少有2名男生的班号

select class from student where ssex = ‘男‘ 
group by class 
having count(ssex) >= 2;

35. 查询Student表中不姓“王”的同学记录

select * from student where sname not like ‘王%‘;

36. 查询student表中每个学生的姓名和年龄

# 解法一
select sname, year(curdate())-year(sbirthday) age from student;
# 解法二
select sname, year(now())-year(sbirthday) age from student;

37. 查询student表中最大和最小的sbirthday日期值

select sname,max(sbirthday) birthday from student
where sbirthday in (
select max(sbirthday) from student )
union
select sname,min(sbirthday) birthday from student
where sbirthday in (
select min(sbirthday) from student );

38. 以班号和年龄从大到小的顺序查询student表中的全部记录

select * from student 
order by class desc,
year(now())-year(sbirthday()) desc;

39. 查询"男"教师及其所上的课程

select a.tname,b.cname from teacher a 
join course b
on a.tno = b.tno
where a.tsex = ‘男‘;

40. 查询和“李军”同性别并同班的同学sname

select sname from student where ssex in (
select ssex from student where sname = ‘李军‘)
and class in (
select class from student where sname = ‘李军‘)
and sname != ‘李军‘;

41. 查询所有选修“计算机导论”课程的“男”同学的成绩表

# 解法一
select a.* from score a join (course b,student c)
on a.cno = b.cno and a.sno = c.sno
where c.ssex = ‘男‘ and a.cno in (
select cno from course where cname = ‘计算机导论‘
);
# 解法二
select a.* from score a join (course b,student c)
using (sno,cno)
where c.ssex = ‘男‘ and b.cname = ‘计算机导论‘;

 

 

References：

1. 深入浅出MySQL (豆瓣)
2. MySQL必知必会 (豆瓣)
3. 经典SQL练习题 - CSDN博客

转自于：https://zhuanlan.zhihu.com/p/29413183?utm_source=qq&utm_medium=social