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）。用SQL语句创建四个表并完成相关题目。
建表语句
#添加学生信息
drop table if exists Student;
create table if not exists Student(
sno varchar(20) not null primary key comment '学生编号',
sname varchar(20) not null comment '名称',
ssex varchar(20) not null comment '性别',
sbirthday datetime comment '生日',
class varchar(20) comment '班级'
)comment ='学生表';
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');
#添加教师表
drop table if exists Teacher;
create table if not exists Teacher(
tno varchar(20) not null primary key comment '教师编号',
tname varchar(20) not null comment '教师姓名',
tsex varchar(20) not null comment '教师性别',
tbirthday datetime comment '教师生日',
prof varchar(20) comment '课程',
depart varchar(20) not null comment '部门'
)comment '教师表';
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');
#添加课程表
drop table if exists Course;
create table if not exists Course(
cno varchar(20) not null primary key comment '课程编号',
cname varchar(20) not null comment '课程名称',
tno varchar(20) not null comment '执教老师编号',
foreign key(tno) references Teacher(tno)
)comment '课程表';
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');
#添加成绩表
drop table if exists Score;
create table if not exists Score(
sno varchar(20) not null comment '学生编号',
foreign key(sno) references Student(sno),
cno varchar(20) not null comment '课程编号',
foreign key(cno) references Course(cno),
degree decimal(4,1) comment '课程分数',
primary key(sno, cno)
)comment '成绩表';
insert into Score values('101','3-105','64');
insert into Score values('103','3-105','92');
insert into Score values('103','3-245','86');
insert into Score values('103','6-166','85');
insert into Score values('105','3-105','88');
insert into Score values('105','3-245','75');
insert into Score values('105','6-166','79');
insert into Score values('109','3-105','78');
insert into Score values('109','3-245','68');
insert into Score values('109','6-166','81');
1、 查询Student表中的所有记录的Sname、Ssex和Class列。
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1
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select
Sname,Ssex,Class
from S
tudent
|
2、 查询教师所有的单位即不重复的Depart列。
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select
distinct
Depart
from T
eacher
|
3、 查询Student表的所有记录。
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select
*
from S
tudent
|
4、 查询Score表中成绩在60到80之间的所有记录。
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1
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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。
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1
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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。
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1
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select
*
from
Student
where
class=
'95031'
or
Ssex=
'女'
|
7、 以Class降序查询Student表的所有记录。
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select
*
from S
tudent
order
by
class
desc
|
8、 以Cno升序、Degree降序查询Score表的所有记录。
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select
*
from
Score
order
by
cno
asc
,degree
desc
|
9、 查询“95031”班的学生人数。
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1
|
select
count
(*)
from S
tudent
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）
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1
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select
Sno,Cno
from
Score
where
Degree=(
select
max
(Degree)
from
Score)
|
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1
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select
Sno,Cno
from
Score
order
by
Degree
desc
limit 0,1
|
11、 查询每门课的平均成绩。
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1
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select
Cno,
avg
(degree)
from
Score
group
by
Cno
|
12、 查询Score表中至少有4名学生选修的并以3开头的课程的平均分数。
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1
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select
avg
(Degree)
from S
core
where
Cno
like
'3%'
and
Cno
in
(
select
Cno
from S
core
group
by
Cno
having
count
(*)>=4) 用
in
不用= 是因为可能会有多个
|
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简单写法：
select
avg
(Degree)
from S
core
where
Cno
like
'3%'
and
group
by
Cno
having
count
(*)>=4
|
13、 查询分数大于70，小于90的Sno列。
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select
Sno
from
Score
where
degree>70
and
degree<90
|
14、 查询所有学生的Sname、Cno和Degree列。
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select
Sname, Cno,Degree
from
Score , Student
where
Score.Sno=Student.Sno
|
15、 查询所有学生的Sno、Cname和Degree列。
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1
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select
Sno,Cname,Degree
from
Score , Course
where
Score.Cno=Course.Cno
|
16、 查询所有学生的Sname、Cname和Degree列。
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1
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select
Sname,Cname,Degree
from S
tudent,Course,Score
where S
tudent.Sno=Score.Sno
and C
ourse.Cno=Score.Cno
|
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join
..
on
写法：
select
Sname,Cname,Degree
from
student
join
score
on
student.Sno=score.Sno
join
course
on
course.Cno=score.Cno
|
17、 查询“95033”班学生的平均分。
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select
avg
(degree)
as
'class=95033'
from
Score
where
Sno
in
(
select
Sno
from
Student
where
Class=
'95033'
)
|
18、 假设为了区分成绩的ABCDE等级，使用如下命令建立了一个Grade表：
#年级表
drop table if exists Grade;
create table if not exists Grade(
low int(3) not null comment '最低分',
upp int(3) not null comment '最高分',
rrank char(1) not null comment '排名'
)comment '年级排名表';
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rrank列。
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select
Sno,Cno,rrank
from
Score,Grade
where
degree
between
low
and
upp
|
19、查询选修“3-105”课程成绩中，高于“109”号同学所有科目的最高成绩的所有分数记录。
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1
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select
*
from S
core
where
Cno=
'3-105'
and
degree>(
select
max
(degree )
from
Score
where
Sno=
'109'
)
|
20、选了多门课程并且是这个课程下不是最高分的。
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select
*
from S
core a
where
Sno
in
(
select
Sno
from S
core
group
by
Sno
having
count
(*)>1)
and
degree<(
select
max
(degree )
from
Score b
where
b.cno = a.cno)
|
21、查询课程号为“3-105”中，成绩高于109学生的所有记录。
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Select
*
from
score
where
degree>(
select
degree
from
Score
where
Sno=
'109'
and
Cno=
'3-105'
)
|
22、查询和学号为108、101的同学同年出生的所有学生的Sno、Sname和Sbirthday列。
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select
sno,sname,sbirthday
from S
tudent
where
year
(sbirthday) in (
select
year
(sbirthday)
from S
tudent
where
sno in (101,
108
)
|
23、查询“张旭“教师任课的学生成绩。
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1
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select
Sno,degree
from S
core,Course
where S
core.Cno=Course.Cno
and
Course.Tno= (
select
Tno
from
Teacher
where
Tname=
'张旭'
)
|
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1
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select
degree
from S
core
where
Cno
in
(
select
cno
from C
ourse
where
Tno= (
select
Tno
from
Teacher
where
Tname=
'张旭'
) )
|
24、查询选修某课程的同学人数至少4人的教师姓名。
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1
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select
Tname
from
Teacher, Course
where
Teacher.Tno=Course.Tno
and
Course.Cno =(
select
Cno
from
Score
group
by
Cno
having
count
(*)>=4)
|
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1
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select
Tname
from
Teacher
where
tno=(
select
Tno
from
Course
where
cno=(
select
Cno
from
Score
group
by
Cno
having
count
(*)>=4 ))
|
25、查询95033班和95031班全体学生的记录。
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1
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select
*
from S
tudent
where
class
in
(
'95033'
,
'95031'
)
|
26、 查询存在有85分以上成绩的课程Cno.
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select
Cno
from S
core
where
degree>85
|
27、查询出“计算机系“教师所教课程的成绩表。
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1
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select
*
from Score
where
cno
in
(
select
cno
from C
ourse
where
tno
in
(
select
tno
from T
eacher
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。
any:代表括号中任意一个成绩就可以
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select
Cno,Sno,Degree
from S
core
where
cno=
'3-105'
and
degree >
any
(
select
degree
from S
core
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.
all:代表括号中的所有成绩
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1
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select
Cno,Sno,Degree
from S
core
where
cno=
'3-105'
and
degree >
all
(
select
degree
from S
core
where
cno=
'3-245'
)
order
by
degree
desc
|
31、 查询所有教师和同学的name、sex和birthday.
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1
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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.
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1
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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。
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1
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select
*
from S
core a
where
degree < (
select
avg
(degree)
from S
core b
where
b.cno=a.cno)
|
34、 查询所有任课教师的Tname和Depart.
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1
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select
Tname,Depart
from
Teacher
where
tno
in
(
select
tno
from
course )
|
35 、 查询所有未讲课的教师的Tname和Depart.
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1
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select
Tname,Depart
from
Teacher
where
Tno
not
in
(
select
Tno
from
Course
where
cno
in
(
select
cno
from
score ))
|
36、查询至少有2名男生的班号。
|
1
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select
class
from S
tudent
where
ssex=
'男'
group
by
class
having
count
(*)>1
|
37、查询Student表中不姓“王”的同学记录。
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1
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select
*
from
Student
where
Sname
not
like
'王%%'
|
38、查询Student表中每个学生的姓名和年龄。
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1
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select
Sname,
year
(now())-
year
(sbirthday)
from
Student
|
39、查询Student表中最大和最小的Sbirthday日期值。
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1
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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。
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1
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select
*
from
Student
order
by
class
desc
, Sbirthday
|
41、查询“男”教师及其所上的课程。
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1
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select
Tname,Cname
from C
ourse,Teacher
where C
ourse.tno= Teacher.tno
and T
eacher.Tsex=
'男'
|
42、查询最高分同学的Sno、Cno和Degree列。
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1
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select
Sno,Cno,Degree
from S
core
where
degree=(
select
max
(degree)
from S
core)
|
排序写法：
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1
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select
Sno,Cno,Degree
from S
core
order
by
degree
desc
limit 0,1
|
43、查询和“李军”同性别的所有同学的Sname.
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1
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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.
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1
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select
Sname
from
Student
where
Ssex = (
select
Ssex
from
Student
where
Sname=
'李军'
)
and
class=(
select
class
from S
tudent
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。
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1
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select
Sno,Cno,degree
from S
core
where
Cno=(
select
Cno
from C
ourse
where
Cname=
'计算机导论'
)
and
Sno
in
(
select
Sno
from S
tudent
where
Ssex=
'男'
)
|
来源：oschina
链接：https://my.oschina.net/u/4341017/blog/4116022