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 | varchar (20) | 否 | 学号（主码） |
| Sname | varchar (20) | 否 | 学生姓名 |
| Ssex | varchar (20) | 否 | 学生性别 |
| Sbirthday | datetime | 可 | 学生出生年月 |
| Class | varchar (20) | 可 | 学生所在班级 |
表（二）Course（课程表）
| 属性名 | 数据类型 | 可否为空 | 含 义 |
| Cno | varchar (20) | 否 | 课程号（主码） |
| Cname | varchar (20) | 否 | 课程名称 |
| Tno | varchar (20) | 否 | 教工编号（外码） |
表（三）Score(成绩表)
| 属性名 | 数据类型 | 可否为空 | 含 义 |
| Sno | varchar (20) | 否 | 学号（外码） |
| Cno | varchar (20) | 否 | 课程号（外码） |
| Degree | Decimal(4,1) | 可 | 成绩 |
| 主码：Sno+ Cno | |||
表（四）Teacher(教师表)
| 属性名 | 数据类型 | 可否为空 | 含 义 |
| Tno | varchar (20) | 否 | 教工编号（主码） |
| Tname | varchar (20) | 否 | 教工姓名 |
| Tsex | varchar (20) | 否 | 教工性别 |
| Tbirthday | datetime | 可 | 教工出生年月 |
| Prof | varchar (20) | 可 | 职称 |
| Depart | varchar (20) | 否 | 教工所在部门 |
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 |
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 |
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
| 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 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 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 Cno,sno 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 AVG(Degree) from Score group by cno having count(cno)>=5 and Cno like '3%'
select AVG(Degree) from Score where Cno like '3%' group by cno having count(cno)>=5
13、查询分数大于70，小于90的Sno列。
Select Sno from Score where Degree between 70 and 90
Select Sno from Score where Degree>70 and Degree<90
14、查询所有学生的Sname、Cno和Degree列。
select Sname,Cno,Degree from Student join Score on Student.Sno=Score.Sno
15、查询所有学生的Sno、Cname和Degree列。
select Cname,Sno,Degree from course join Score on course.cno=Score.cno
16、查询所有学生的Sname、Cname和Degree列。
select Cname,Sname,Degree from course , Score ,Student where Student.Sno=Score.Sno and Course.cno=Score.Cno
select Cname,Sname,Degree from course join Score on Course.cno=Score.Cno join Student on Student.Sno=Score.Sno
17、 查询“95033”班学生的平均分。
select avg(degree) from score,student where score.sno=student.sno and class='95033'
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 join grade on score.Degree between grade.low and grade.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 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 a where sno in (Select sno from score group by sno having count(*)>1) and degree<(select max(degree) from score b where b.cno=a.cno)
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 Degree from score where cno in( Select cno from course where tno in(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 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。
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 distinct 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'))
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 = '计算机系'and prof in (select prof from teacher where depart ='电子工程系'))
union
select Tname,Prof from teacher where prof not in (select prof from teacher where depart = '电子工程系'and prof in (select prof from teacher where depart ='计算机系'))
select Tname,Prof from teacher a where prof not in (select prof from teacher b where a.depart !=b.depart)
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>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 Cno,Sno,Degree 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.
select sname as name,ssex as sex,sbirthday as birthday 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 as name,ssex as sex,sbirthday as birthday 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 degree 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(*)>=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(GETDATE())-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 ASC
41、查询“男”教师及其所上的课程。
Select tname,cname from teacher join course on teacher.tno=course.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)
select top 1 Sno,Cno,Degree from score order by degree desc
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 wheresname='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 degree 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')