create database kaoshi 
go
use kaoshi
go
create table Student
(
 Sn char(3) primary key,
 Sname char(8),
 Ssex char(2),
 Sbirthday datetime,
 class char(5),
 )
 create table Course
 (
 Cno char(5) primary key,
 Cname varchar(10),
 Tno char(3),
 )
 create table Score
 (
 Sno char(3),
 Cno char(5),
 Degree Decimal(4,1),
 )
 create table Teacher
 (
 Tno Char(3) primary key,
 Tname Char(4),
 Tsex Char(2),
 Tbirthday    datetime,
 Prof    Char(6),
 Depart    Varchar(10),
 )
 go
 
 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)
 
 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)
 
 insert into Score values(103,‘3-245‘,86)
 insert into Score values(105,‘3-245‘,75)
 insert into Score values(109,‘3-245‘,68)
 insert into Score values(103,‘3-105‘,92)
 insert into Score values(105,‘3-105‘,88)
 insert into Score values(109,‘3-105‘,76)
 insert into Score values(101,‘3-105‘,64)
 insert into Score values(107,‘3-105‘,91)
 insert into Score values(108,‘3-105‘,78)
 insert into Score values(101,‘6-166‘,85)
 insert into Score values(107,‘6-166‘,79)
 insert into Score values(108,‘6-166‘,81)
 
 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‘)
 
--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
--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
 select *from Student where 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=(select MAX(Degree) from score)
--11、 查询每门课的平均成绩。
 select avg(Degree) from Score where Cno=‘3-245‘
 select avg(Degree) from Score where Cno=‘3-105‘
 select avg(Degree) from Score where Cno=‘6-166‘
--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 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 Student.Sname,Score.Cno,Degree from Student join Score on Student.Sn= Score.Sno
--15、查询所有学生的Sno、Cname和Degree列。
 select Sno,Degree,Cname from Score join Course on Score.Cno=Course.Cno
--16、查询所有学生的Sname、Cname和Degree列。
 select Sname,Cname,Degree from score join student on Score.Sno=Student.Sn join Course on Score.Cno=Course.Cno
--17、 查询“95033”班学生的平均分。
 select * from Student where class=95033 select AVG(Degree) from Score
--18、 假设使用如下命令建立了一个grade表：
create table grade
(
low  int,
upp  int,
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 Score.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 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 where sno in (select sno from score group by sno having count(*)>1) and degree <(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 Cno=‘3-105‘ and  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 datediff(year,sbirthday,getdate())=(select datediff(year,sbirthday,getdate()) 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 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 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 depart=‘计算机系‘ and prof not in (select prof from teacher where depart=‘电子工程系‘)
  union
  select tname,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>(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 Tname,Tsex,Tbirthday from Teacher
  union
  select Sname,Ssex,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 where Degree<(select avg(Degree) from Score)
--34、 查询所有任课教师的Tname和Depart.
 select Tname,Depart from Teacher,Course where Teacher.Tno=Course.Tno
--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 as 姓名,datediff(year,sbirthday,getdate()) as 年龄 from student
--39、查询Student表中最大和最小的Sbirthday日期值。
 select Sname,Sbirthday as 大 from Student where Sbirthday =(select min(Sbirthday) from Student)
 union
 select Sname,Sbirthday as 小 from Student where Sbirthday =(select max(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,Sname,Sbirthday from Student order by class desc,Sbirthday;
--41、查询“男”教师及其所上的课程。
 select Tname,Cname from Teacher ,Course  where Teacher.Tno=Course.Tno and Tsex=‘男‘
--42、查询最高分同学的Sno、Cno和Degree列。
 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=(select Cno from Course where Cname=‘计算机导论‘)