6.5数据库练习题

一、            设有一数据库，包括四个表：学生表（Student）、课程表（Course）、成绩表（Score）以及教师信息表（Teacher）。四个表的结构分别如表1-1的表（一）~表（四）所示，数据如表1-2的表（一）~表（四）所示。用SQL语句创建四个表并完成相关题目。

                 表1-1数据库的表结构 

表（一）Student (学生use)                         

表（二）Course（课程表）

表（三）Score(成绩表)

表（四）Teacher(教师表)

表1-2数据库中的数据

表（一）Student

表（二）Course

表（三）Score

表（四）Teacher

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 depart from teacher group by depart;

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 = 85 or degree = 86 or degree = 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。

Select * from student order by class desc;

8  以Cno升序、Degree降序查询Score表的所有记录。

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。（子查询或者排序）

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

11   查询每门课的平均成绩。

Select cno，avg(degree) from score group by cno

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

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

13查询分数大于70，小于90的Sno列。

Select sno from score where degree>70 and degree<90;

14查询所有学生的Sname、Cno和Degree列。

Select a.sname,b.cno,b.degree from student as a,score as b where a.sno=b.sno

15、查询所有学生的Sno、Cname和Degree列。

Select  a.sno,b.cname,a.degree from score as a, course as b where a.cno=b.cno;

16、查询所有学生的Sname、Cname和Degree列。

select student.Sname,course.Cname,score.Degree from student,course,score where student.sno=score.sno and course.cno=score.cno;

17、 查询“95033”班学生的平均分。

select avg(degree) from score where sno in(select sno from student where class="95033");

18  查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录。

select * from score where cno="3-105" and degree > (select degree from score where cno="3-105" and sno="109");

20、查询score中选学多门课程的同学中分数为非最高分成绩的记录。

select * from score where  sno in (select sno from score  group by sno having count(sno)>1)and degree not in (select max(degree) from score);

21、 查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。

select * from score where degree > (select degree from score where sno="109" and cno="3-105");

22、查询和学号为108的同学同年出生的所有学生的Sno、Sname和Sbirthday列。

Select sno, sname,sbirthday from student where year(sbirthday)=(select year(sbirthday) from student where sno= 108);

23、查询“张旭“教师任课的学生成绩（姓名）。

1、从成绩表 查询学生成绩  

2、条件是这个课程是 “张旭“教师任课

A)从老师表 中查名字叫 张旭 编号

B)根据老师编号 在课程表中找到对应的 课程号

Select degree from score where score .cno=(select course.cno from course where

Course.tno =(select teacher.tno from teacher where teacher.tname="张旭"));

查询考计算机导论的学生成绩

Select degree from score where cno =(Select course.cno from course where cname ="计算机导论")

查询 所有的列/字段 从 成绩表(score) 条件是

课程编号是：课程表(course)中 课程名(cname)称为计算机导论 的课程编号

课程表(course)中 课程名(cname)称为计算机导论 的课程编号===3-105

查询 所有的列/字段 从 成绩表(score) 条件是 课程编号是：3-105

查询李诚老师教的课程名称

Select cname from course where tno = (Select tno from teacher where tname ="李诚"）;

教高等数学的老师是哪个系的

Select depart from teacher where tno =(select tno from course where cname = "高等数学");

24、查询选修某课程的同学人数多于5人的教师姓名。

Select tname from teacher where tno=(select tno from course where cno=

(Select cno from score group by cno having count(cno)>5));

25、查询95033班和95031班全体学生的记录。

Select * from student where class = "95033" or class ="95031";

26、  查询存在有85分以上成绩的课程Cno.

Select cno from course where cno in(select cno from score where degree>85);

27、查询出“计算机系“教师所教课程的成绩表。

Select degree from score where cno in

(Select cno from course where tno in (Select tno from teacher where depart = "计算机系"));

29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学 的Cno、Sno和Degree,并按Degree从高到低次序排序。

select cno,sno,degree from score where cno="3-105"and degree > (select max(degree) from score where cno="3-245")order by degree desc;

30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的 Cno、Sno和Degree.

select cno,sno,degree from score where cno="3-105"and degree > (select max(degree) from score where cno="3-245");

31、 查询所有教师和同学的name、sex和birthday.

select teacher.Tname ,teacher.Tsex ,teacher.Tbirthday  from teacher
union
select student.Sname,student.Ssex ,student.Sbirthday  from student;

32查询所有“女”教师和“女”同学的name、sex和birthday.

Select tname,tsex,tbirthday from teacher where tsex ="女"

Union

Select sname,ssex,sbirthday from student where ssex ="女"

33、 查询成绩比该课程平均成绩低的同学的成绩表。

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

       Where b. cno = a.cno 限制每门课的平均成绩。

34、 查询所有任课教师的Tname和Depart.

select tname,depart from teacher where tno in(select tno from course where cno in(select cno from score));

35、查询所有未讲课的教师的Tname和Depart.

 select tname,depart from teacher where tno in(select tno from course where cno not in(select cno from score));

36、查询至少有2名男生的班号。

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

37 查询Student表中不姓“王”的同学记录。

Select * from  student  where sname not like "王%";

38、查询Student表中每个学生的姓名和年龄。

select sname,(year(now())-year(sbirthday)) as age  from student;

39、查询Student表中最大和最小的Sbirthday日期值。

Select max(sbirthday),min(sbirthday) from student;

40、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,sbirthday asc;

41、查询“男”教师及其所上的课程。

Select cname from course where tno in (Select tno from teacher where tsex = "男");

select teacher.tname,course.cname from teacher, course  where course.tno=teacher.tno and teacher.tsex="男";

42、查询最高分同学的Sno、Cno和Degree列。

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

43、查询和“李军”同性别的所有同学的Sname.

Select sname from student where ssex =(select ssex from student where sname = "李军")

44、查询和“李军”同性别并同班的同学Sname.

select sname from student as a where ssex=(select ssex from student as b where  sname="李军"and a.class=b.class); 

45、查询所有选修“计算机导论”课程的“男”同学的成绩表。

select * from score where cno=(select cno from course where cname="计算机导论") and sno in (select sno from student where ssex="男");

6.5数据库练习题

原文：https://www.cnblogs.com/sunhao1987/p/9142271.html