mysql50题_MySQL练习题
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1-2数据库中的数据 ：
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 (where degree>=60 && degree <=80)
5、查询Score表中成绩为85，86或88的记录。
select * from score where degree==85||degree==86||degree==88 (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 studnt 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)
排序：select Sno,Cno from score order by degree desc limit 0,1
⼦查询：select Sno,Cno from score where degree=(select max (Degree) from score)
11、查询每门课的平均成绩。按照课程分组(group by)，查询每门课平均成绩
select 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。
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查询以3开头的课程 select Cno from score where Cno like “3%”
mysql面试题学生表查询⾄少有5名学⽣选修的课程号 select Cno from score group by Cno having count (*)>=5
select avg(degree),Cno from score where Cno in (selet Cno from score where Cno like "3%" group by Cno having
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13、查询分数⼤于70，⼩于90的Sno列。
select Sno from score where degree>70 and degree (select Degree from score where Sno='109' and Cno='3-105')
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 a where Sno in (select Sno from score group by Sno having count(*)>1) and degree
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。
Select * from score where Cno in (Select Cno from course where Tno=(Select Tno from teacher where Tname='张旭'))
24、查询选修某课程的同学⼈数多于5⼈的教师姓名。
Select *from teacher where Tno in( select Tno from course where Cno in (Select Cno from score group by Cno having count(*)>5))
25、查询95033班和95031班全体学⽣的记录。
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select * from student where Class in ('95033','95031')
26、查询存在有85分以上成绩的课程Cno.
Select Cno from score group by Cno having max(degree)>85
27、查询出“计算机系“教师所教课程的成绩表。
Select * from score where Cno in (select Cno from course where Tno in (Select Tno from teacher where depart ='计算机系')免费的代码资源网站
28、查询“计算机系”与“电⼦⼯程系“不同职称的教师的Tname和Prof。
Select * from teacher where Prof not in (Select Prof from teacher where Depart ='计算机系' and prof in (select prof from teacher where Depart='电⼦⼯程系'))
select * from teacher where prof in (select prof from teacher where depart ='计算机系' and prof not in (select prof from teacher where depart='电⼦⼯程系')) union select * from teacher where prof in (sele
ct prof from teacher where depart ='电⼦⼯程系' and prof not in (select prof 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 * from score where Cno='3-105' and degree> any(select 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 * from score where Cno=’3-105’and degree> all (select degree from score where Cno=’3-245’)
31、 查询所有教师和同学的name、sex和birthday.
values是什么牌子Select Sname, Ssex, Sbirthday from student union select Tname, Tsex, Tbirthday from teacher
32、查询所有“⼥”教师和“⼥”同学的name、sex和birthday.
Select Sname, Ssex, Sbirthday from student where Ssex='⼥' union select Tname, Tsex, Tbirthday from teacher where
Tsex='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 a where degree< (select avg(degree) from score b where a.Cno=b.Cno)
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 distinct 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 not in (Select Tno from course where Cno in (Select distinct 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(Ssex)>=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 Class,year(now())-year(Sbirthday) as age from student order by Class desc, age
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')
42、查询最⾼分同学的Sno、Cno和Degree列。
Select * from score order by degree desc limit0,1 select * 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 where Ssex=( Select Ssex from student where Sname='李军')and Class=( Select Class from student where Sname='李军')
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 Sno in (select Sno from student where Ssex='男') and Cno in (select Cno from course where Cname='计算机导论')
SQL练习题完整(做完你就是⾼⼿)
SQL 练习题答案 ⼀.补充作业⼀.  设有三个关系:                S(SNO, SNAME, AGE, SEX,Sdept)                SC(SNO, CNO ...
50道sql练习题和答案

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