sql练习题

--第一题 查询Student表中的所有记录的Sname、Ssex和Class列。
select Sname,Ssex,Class from student

--第二题 查询教师所有的单位即不重复的Depart列。
select distinct Depart from Teacher

--第三题 查询Student表的所有记录。
select * from student

--第四题 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

--第五题 查询Score表中成绩为85，86或88的记录。
select * from Score where Degree in (‘85‘,‘86‘,‘88‘)

--第六题 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‘

--第七题 以Class降序查询Student表的所有记录。
select * from student order by Class desc

--第八题 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

--第九题 查询“95031”班的学生人数。
select count(*) from student where Class=‘95031‘ --*可以换成主键值

--第十题 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)

--第十一题 查询每门课的平均成绩。
select Cno,AVG(Degree) as 平均分 from Score group by Cno

select Cname from Course where Cno in (select Cno a from Score group by Cno) 
union
select Cno,AVG(Degree) from Score group by Cno

--第十二题 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 where Cno like ‘3%‘ group by Cno having COUNT(Cno)>4

--第十三题 查询分数大于70，小于90的Sno列。
select sno from Score where Degree between 70 and 90

--第十四题 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

--第十五题 查询所有学生的Sno、Cname和Degree列。
select Sno,Cname,degree from Score join Course on Course.Cno=Score.Cno

--第十六题 查询所有学生的Sname、Cname和Degree列。
select student.Sname,Cname,degree from student join Score on student.Sno=Score.Sno join Course on Course.Cno=Score.Cno

--第十七题 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‘)

select AVG(Degree) from Score,student where student.Sno=Score.Sno and Class=‘95033‘

--第十八题 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,Degree,[RANK] from grade join Score on Score.Degree between low and upp

select Sno,Cno,Degree,[RANK] from Score,grade where Degree between low and upp

--第十九题 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 student,Score where Score.Cno=‘3-105‘ and student.Sno=Score.Sno and Score.Degree>

(select Degree from Score where Cno=‘3-105‘ and Sno=‘109‘)

--第二十题 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。
-- 理解1
  select * from Score a where Sno in

(select Sno from Score group by Sno having count(*)>1 ) and Degree not in

(select max(Degree) from Score b where   b.Cno = a.Cno) 
-- 理解2
  select * from Score a where Sno in

(select Sno from Score group by Sno having count(*)>1 ) and Degree not in

(select max(Degree) from Score a where   Sno in (select Sno from Score group by Sno having count(*)>1 ))

--第二十一题 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‘)

--第二十二题 查询和学号为107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(student.Sbirthday)=

(select year(Sbirthday) from student where Sno=‘107‘)

--第二十三题 查询“张旭“教师任课的学生成绩。
-- select Degree from Score,Teacher,Course where Teacher.Tname=‘张旭‘ and Teacher.Tno=Course.Tno and Course.Cno=Score.Cno

select Sno,Cno,Degree from Score where Cno in (select Cno from Course where Tno in 
(select Tno from Teacher where Tname=‘张旭‘))

--第二十四题 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) )

--第二十五题 查询95033班和95031班全体学生的记录。
select * from student where Class=‘95033‘ or Class=‘95031‘

--第二十六题 查询存在有85分以上成绩的课程Cno.
select distinct cno from Score where Degree>85

--第二十七题 查询出“计算机系“教师所教课程的成绩表。
select sno,Cno ,Degree from Score where Cno in 
(select Cno from Course where Tno in (select tno from Teacher where Depart=‘计算机系‘))

--第二十八题 查询“计算机系”与“电子工程系“不同职称的教师的Tname和Prof。使用相关子查询
select Tname,Prof from Teacher a where Prof not in(select Prof from Teacher b where a.Depart!=b.Depart)

--第二十九题 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”课程的同学的Cno、Sno和Degree,并按Degree从高到低次序排序。
select Cno,Sno,Degree from Score a where (select Degree from Score b where Cno=‘3-105‘ and b.Sno=a.Sno)>=
(select Degree from Score c where Cno=‘3-245‘ and c.Sno=a.Sno) order by Degree desc


select * from Score where Cno=‘3-105‘ and Degree >any(select Degree from Score where Cno=‘3-245‘)

--第三十题 查询选修编号为“3-105”课程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 a where (select Degree from Score b where Cno=‘3-105‘ and b.Sno=a.Sno)>
(select Degree from Score c where Cno=‘3-245‘ and c.Sno=a.Sno)


select * from Score where Cno=‘3-105‘ and Degree>all(select Degree from Score where Cno =‘3-245‘) 
--第三十一题 查询所有教师和同学的name、sex和birthday.
select distinct Sname as name,Ssex as sex,Sbirthday as birthday from student
union
select distinct Tname as name,Tsex as sex,Tbirthady as birthday from Teacher

--第三十二题 查询所有“女”教师和“女”同学的name、sex和birthday.
select distinct Sname as name,Ssex as sex,Sbirthday as birthday from student where Ssex=‘女‘
union
select distinct Tname as name,Tsex as sex,Tbirthady as birthday from Teacher where Tsex=‘女‘

--第三十三题 查询成绩比该课程平均成绩低的同学的成绩表。
select Sno,Cno,Degree from Score a where a.Degree<(select AVG(Degree) from Score b where a.Cno=b.Cno)

--第三十四题 查询所有任课教师的Tname和Depart.
select Tname,Depart from Teacher where Tname in 
(select distinct Tname from Teacher,Course,Score where Teacher.Tno=Course.Tno and Course.Cno=Score.Cno)

select Tname,Depart from Teacher where tno in 
(select tno from course where Cno in (select distinct Cno from Score))

--第三十五题 查询所有未讲课的教师的Tname和Depart. 
select Tname,Depart from Teacher where Tname not in 
(select distinct Tname from Teacher,Course,Score where Teacher.Tno=Course.Tno and Course.Cno=Score.Cno)
--第三十六题 查询至少有2名男生的班号。
select Class FROM student where Ssex=‘男‘ group by Class having COUNT(*)>1

--第三十七题 查询Student表中不姓“王”的同学记录。
select * from student where Sname not like (‘王%‘)

--第三十八题 查询Student表中每个学生的姓名和年龄。
select Sname,YEAR(GETDATE())-year(Sbirthday) from student

--第三十九题 查询Student表中最大和最小的Sbirthday日期值。
select MAX(Sbirthday) as 最大,MIN(Sbirthday) as 最小 from student

--第四十题 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

--第四十一题 查询“男”教师及其所上的课程。
select Tname,Cname from Teacher,Course where Tsex=‘男‘ and Teacher.Tno=Course.Tno


--第四十二题 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* from Score order by Degree desc

--第四十三题 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‘) and Sname not in (‘李军‘)

--第四十四题 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 Sname not in (‘李军‘) 

and Class=(select Class from student where Sname=‘李军‘)

--第四十五题 查询所有选修“计算机导论”课程的“男”同学的成绩表。
select Sno,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‘)