数据库45个题

create database test
go
use test
go
create table student
(
    --学号
    sno varchar(3) not null primary key,
    --姓名
    sname varchar(4) not null,
    --性别
    ssex varchar(2) not null,
    --出生年月
    sbirthday datetime,
    --所在班级
    class varchar(5)
)
go
create table teacher
(
    --教工编号
    tno varchar(3) not null primary key,
    --教工姓名
    tname varchar(4) not null,
    --教工性别
    tsex varchar(2) not null,
    --教工出生日期
    tbirthday datetime,
    --职称
    prof varchar(6),
    --所在部门
    depart varchar(10)
)
go
create table course
(
    --课程号
    cno varchar(5) not null primary key,
    --课程名称
    cname varchar(10) not null,
    --教工编号
    tno varchar(3) references teacher(tno)
)
go
create table score
(
    --学号
    sno varchar(3) not null references student(sno),
    --课程号
    cno varchar(5) not null references course(cno),
    --成绩
    degree decimal(4,1)
)
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 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','1958-08-14','助教','电子工程系')

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')

select * from student
select * from teacher
select * from course
select * from score



--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。
--4、查询Score表中成绩在到之间的所有记录。
select * from score where degree  between 60 and 80
--5、查询Score表中成绩为，或的记录。
select * from score where degree in(85,86,88)
--6、查询Student表中“”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“”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。
select * from score
select MAX(degree) from score   --92
select sno,cno from score where degree=(select MAX(degree) from score)
--11、查询‘-105’号课程的平均分。
select AVG(degree) from score where cno='3-105'
--12、查询Score表中至少有名学生选修的并以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(*)>=5

--13、查询最低分大于，最高分小于的Sno列。--假定按学生算。
select sno,MAX(degree),MIN(degree) from score group by sno having MAX(degree)<90 and MIN(degree)>70

--14、查询所有学生的Sname、Cno和Degree列。
select * from student
select * from score

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 * from course
select * from score

select sno,cname,degree from course join score on course.cno = score.cno
--16、查询所有学生的Sname、Cname和Degree列。
select * from student
select * from course
select * from score

select sname,cname,degree from student
    join score on student.sno = score.sno
    join course on course.cno = score.cno

--17、查询“”班所选课程的平均分。
select * from student
select * from score
select sno from student where class='95033'   --101,107,108
select * from score where sno in(101,107,108)
select AVG(degree) from score where sno in(select sno from student where class='95033' )

select AVG(score.degree) from student join score on student.sno = score.sno where student.class='95033'

--18、假设使用如下命令建立了一个grade表：
create table grade(low  int,upp  int,rank  varchar(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 * from grade
select * from score
select sno,cno,rank from grade join score on score.degree>=grade.low and score.degree<=grade.upp
--19、查询选修“-105”课程的成绩高于“”号同学成绩的所有同学的记录。
select * from score
select * from score where cno='3-105'  and degree>(select degree from score where cno='3-105' and sno='109')

select degree from score where cno='3-105' and sno='109'   --76

--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。


--21、查询成绩高于学号为“”、课程号为“-105”的成绩的所有记录。
delete from score
select*from score where sno='109'
select sno ,cno from score 
--22、查询和学号为的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
--23、查询“张旭“教师任课的学生成绩。
select  *from course   -- 6-166
select *from teacher
select*from score     --101 107 108
select tname from teacher  join course on teacher.tno=course.tno
join score on course.cno=score.cno
select degree from score where cno in (select cno from score where cno='6-166')

--24、查询选修某课程的同学人数多于人的教师姓名。

select*from teacher
select*from score

select cno from score group by cno  having COUNT(cno)>=5
--25、查询班和班全体学生的记录。
select*from student  --王丽曾华李军
select sname,class from student where class='95033'
select  sname ,class from student where  class='95031'
--26、查询存在有分以上成绩的课程Cno.
select*from score 
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
select*from course
select*from teacher
select tno from teacher where depart='计算机系'-- 804 825
select cno from course where tno='804'   --3-105 3-245
select degree from score where cno='3-105'

--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
select  distinct prof  from teacher 
--29、查询选修编号为“-105“课程且成绩至少高于选修编号为“-245”的
--同学的Cno、Sno和Degree,并按Degree从高到低次序排序。

select degree from score where cno in('3-105')--degree92 88 6 64 91 78
select degree from score where cno in('3-245')--86 75 68

select sno,cno ,degree from score order by degree desc

--30、查询选修编号为“-105”且成绩高于选修编号为“-245”课程的同学的Cno、Sno和Degree.

select degree from score where cno in('3-105')--degree92 88 6 64 91 78
select degree from score where cno in('3-245')--86 75 68

--31、查询所有教师和同学的name、sex和birthday.
select*from teacher
select *from course

select*from score
 select*from student 
select tname,tbirthday,tsex,sname,sbirthday ,ssex from teacher
 join course on teacher.tno=course.tno
join score on course.cno=score.cno
join student on score.sno=student.sno

--32、查询所有“女”教师和“女”同学的name、sex和birthday.
select tname ,tsex,tbirthday from teacher,student where tsex in('女')
select sname ,ssex,sbirthday from teacher,student where ssex in('女')

--33、查询成绩比该课程平均成绩低的同学的成绩表。//相关子查询

select avg(degree)from score 
--34、查询所有任课教师的Tname和Depart.
select *from teacher
select *from course
select*from score
select tname ,depart from teacher

--35  查询所有未讲课的教师的Tname和Depart.
 
select distinct cno from score
select  distinct tname ,depart from teacher
join course on teacher.tno=course.tno
join score on score.cno=course.cno
--insert into teacher values('888','aaa','v','2005.1.1','a','a')
--36、查询至少有名男生的班号。
--insert into student values('110','aaa','a','2005.1.1','95000')
select * from student  --95033  95031
select class from student group by class having COUNT(ssex)>=2

--37、查询Student表中不姓“王”的同学记录。
select*from student
select * from student where sname like'王%'
--38、查询Student表中每个学生的姓名和年龄。
select sname, sbirthday 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 desc

--41、查询“男”教师及其所上的课程。
select* 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 in (select max(degree)from score)
--43、查询和“李军”同性别的所有同学的Sname.
select*from student 
select ssex from student where sname='李军'
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 class from student where sname='李军'
select sname ,Class from student where 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 student
select*from score
select*from course
select *from student where ssex='男'
select*from course where cname='计算机导论'
select DEGREE,cname,ssex from student where
join score on student.sno=score.sno
join course on score.cno=course.cno
ssex in(select * from student where ssex='男')
,cname in(select * from course where cname='计算机导论')

--Exists的用法.
--查询带课的老师的信息，
--查询没有带课的老师的信息.