查询
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 (学生表)
|
属性名 |
数据类型 |
可否为空 |
含 义 |
|
Sno |
Char(3) |
否 |
学号（主码） |
|
Sname |
Char(8) |
否 |
学生姓名 |
|
Ssex |
Char(2) |
否 |
学生性别 |
|
Sbirthday |
datetime |
可 |
学生出生年月 |
|
Class |
Char(5) |
可 |
学生所在班级 |
create table Student(
Sno char (3) not null primary key,
Sname char(8) not null ,
Ssex char(2) not null ,
Sbirthday datetime ,
Class char(5)
);
表（二）Course（课程表）
|
属性名 |
数据类型 |
可否为空 |
含 义 |
|
Cno |
Char(5) |
否 |
课程号（主码） |
|
Cname |
Varchar(10) |
否 |
课程名称 |
|
Tno |
Char(3) |
否 |
教工编号（外码） |
create table Course(
Cno char (5)not null primary key,
Cname varchar(10) not null ,
Tno char(3) not null
);
表（三）Score(成绩表)
|
属性名 |
数据类型 |
可否为空 |
含 义 |
|
Sno |
Char(3) |
否 |
学号（外码） |
|
Cno |
Char(5) |
否 |
课程号（外码） |
|
Degree |
Decimal(4,1) |
可 |
成绩 |
|
主码：Sno+ Cno |
|||
create table Score(
Sno char(3) not null ,
Cno char(5) not null,
Degree decimal(4,1)
);
表（四）Teacher(教师表)
|
属性名 |
数据类型 |
可否为空 |
含 义 |
|
Tno |
Char(3) |
否 |
教工编号（主码） |
|
Tname |
Char(4) |
否 |
教工姓名 |
|
Tsex |
Char(2) |
否 |
教工性别 |
|
Tbirthday |
datetime |
可 |
教工出生年月 |
|
Prof |
Char(6) |
可 |
职称 |
|
Depart |
Varchar(10) |
否 |
教工所在部门 |
create table Teacher (
Tno char(3) not null primary key ,
Tname char(4) not null ,
Tsex char(2) not null ,
Tbirthday datetime,
Prof char(6),
Depart varchar(10) not null
);
表1-2数据库中的数据
表（一）Student
|
Sno |
Sname |
Ssex |
Sbirthday |
class |
|
108 |
曾华 |
男 |
1977-09-01 |
95033 |
|
105 |
匡明 |
男 |
1975-10-02 |
95031 |
|
107 |
王丽 |
女 |
1976-01-23 |
95033 |
|
101 |
李军 |
男 |
1976-02-20 |
95033 |
|
109 |
王芳 |
女 |
1975-02-10 |
95031 |
|
103 |
陆君 |
男 |
1974-06-03 |
95031 |
insert into student values('108','曾华','男','1977-09-01','95033');
insert into student values('105','匡明','男','1975-10-02','95031');
insert into student values('107','王丽','女','1976-01-23','95033');
insert into student values('101','李军','男','1976-02-20','95033');
insert into student values('109','王芳','女','1975-02-10','95031');
insert into student values('103','陆君','男','1974-06-03','95031');
表（二）Course
|
Cno |
Cname |
Tno |
|
3-105 |
计算机导论 |
825 |
|
3-245 |
操作系统 |
804 |
|
6-166 |
数字电路 |
856 |
|
9-888 |
高等数学 |
831 |
insert into Course values('3-105','计算机导论','825');
insert into Course values('3-245','操作系统','804');
insert into Course values('6-166','数字电路','856');
insert into Course values('9-888','高等数学','831');
表（三）Score
|
Sno |
Cno |
Degree |
|
103 |
3-245 |
86 |
|
105 |
3-245 |
75 |
|
109 |
3-245 |
68 |
|
103 |
3-105 |
92 |
|
105 |
3-105 |
88 |
|
109 |
3-105 |
76 |
|
101 |
3-105 |
64 |
|
107 |
3-105 |
91 |
|
108 |
3-105 |
78 |
|
101 |
6-166 |
85 |
|
107 |
6-166 |
79 |
|
108 |
6-166 |
81 |
表（四）Teacher
insert into Teacher values('804','李诚','男','1958-12-02','副教授','计算机系');
insert into Teacher values('856','张旭','男','1969-03-12','讲师','电子工程系');
insert into Teacher values('825','王萍','女','1972-05-05','助教','计算机系');
insert into Teacher values('831','刘冰','女','1977-08-14','助教','电子工程系');
|
Tno |
Tname |
Tsex |
Tbirthday |
Prof |
Depart |
|
804 |
李诚 |
男 |
1958-12-02 |
副教授 |
计算机系 |
|
856 |
张旭 |
男 |
1969-03-12 |
讲师 |
电子工程系 |
|
825 |
王萍 |
女 |
1972-05-05 |
助教 |
计算机系 |
|
831 |
刘冰 |
女 |
1977-08-14 |
助教 |
电子工程系 |
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='85' or degree='86' or degree='88'
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。
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 ,Degree desc
9、 查询“95031”班的学生人数。
select count(class) 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=(select max(degree) from Score )
11、 查询每门课的平均成绩。
select avg(degree) ,cno 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 cno,avg(degree) from score where cno =(select cno from score group by cno having count(sno) > =5 and cno like'3%' ) group by cno
Select avg(degree) from score where cno like '3%' and cno in (select cno from score group by cno having count(*)>=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 student.Sname,score.Cno,score.degree from student,score where student.Sno=score.Sno
Select sname, cno,degree from score join student on student.sno=score.sno
15、查询所有学生的Sno、Cname和Degree列。
select Score.sno,Course.Cname,Score.degree from Score,Course where Score.cno=Course.cno
Select sno,cname,degree from score join course on course.cno=score.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 score.Cno=course.Cno
Select sname,cname,degree from score join student on student.sno=score.sno join course on course.cno=score.cno
17、 查询“95033”班学生的平均分。
select student.class,avg(degree) from student ,score where student.sno=score.sno and student.class='95033' group by student.class;
Select avg(degree) from score where sno in (select sno from student where class='95033')
18、 假设使用如下命令建立了一个grade表：
create table grade(low int(3),upp int(3),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’);
现查询所有同学的Sno、Cno和rank列。
select Sno,Cno,rank from score,grade where degree between low and upp order by rank
Select sno,cno,rank from score join grade on degree between low and upp
19、 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 a where a.cno='3-105'and a.degree > (select degree from score b where b.cno='3-105' and b.sno='109' );
Select * from score where cno='3-105'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 b where degree <(select max(degree) from score a where a.cno=b.cno);
Select * from score where degree not in (Select max(degree) from score group by sno having count(*)>1) and sno in (select sno from score group by sno having count(*)>1 )
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 a where a.cno='3-105'and a.degree > (select degree from score b where b.cno='3-105'and b.sno='109');
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 degree from score where cno=(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 tname from teacher where tno =(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。
Select * from student where class in (select class from student where class='95033' or class='95031')
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 where 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') )
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 tname,prof from teacher where prof not in (select prof from teacher where depart='电子工程系')
Select tname ,prof 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'))
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 min(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 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
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(*)>=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 '年龄' 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
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 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 in (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 in (select ssex from student where sname='李军') and class in(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=(select cno from course where cname='计算机导论')
