create table student
(
sno varchar(20) not null primary key,
sname varchar(20) not null,
ssex varchar(20) not null,
sbirthday datetime,
class varchar(20)
);
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');
create table teacher
(
tno varchar(20) not null primary key,
tname varchar(20) not null,
tsex varchar(20) not null,
tbirthday datetime,
prof varchar(20),
depart varchar(20) not null
);
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');
create table course
(
cno varchar(20) not null primary key,
cname varchar(20) not null,
tno varchar(20) not null,
foreign key(tno) references teacher(tno)
);
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');
create table score
(
sno varchar(20) not null primary key,
foreign key(sno) references student(sno),
cno varchar(20) not null,
foreign key(cno) references course(cno),
degree decimal
);
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('101','3-105','92');
insert into score values('107','3-105','88');
insert into score values('108','3-105','76');
insert into score values('109','3-105','64');
insert into score values('104','3-105','91');
insert into score values('100','3-105','78');
insert into score values('102','6-166','85');
insert into score values('104','6-166','79');
insert into score values('109','6-166','81');
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。
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 sno,cno from score where degree=(select max(degree) from score)
--方式二
SELECT sno,cno from score ORDER BY degree desc limit 1
11、 查询每门课的平均成绩。
select cno,avg(degree) 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 where cno like '3%' and cno in(
select cno from score group by cno having count(*)>=5)
--方式二：
select avg(degree) from score where cno like '3%' group by cno having count(*)>=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 sname,cno,degree from score,student where score.sno=student.sno
15、 查询所有学生的Sno、Cname和Degree列。
select sno,cname,degree from score s,course c where s.cno=c.cno
16、 查询所有学生的Sname、Cname和Degree列。
select sname,degree from student s,course c,score sc where s.sno=sc.sno and c.cno=sc.cno
--使用join....on方式
select sname,cname,degree from student s join score sc on s.sno=sc.sno join course c on sc.cno=c.cno
17、 查询“95033”班学生的平均分。
select avg(degree) as avgdegree 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：
drop table grade
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');
select * from grade
SELECT * from score
现查询所有同学的Sno、Cno和rank列。
select score.sno,score.cno,grade.rank from score,grade where 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 max(degree) from score where sno='109' and cno='3-105'
)
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、101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 sno,degree from score s,course c where s.cno=c.cno and c.tno=(
select tno from teacher where tname='张旭'
)
--方式二
select degree from score where cno in(
select cno from course where tno=(
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 t,course c where t.tno=c.tno and c.cno=(
select cno from score GROUP BY cno HAVING count(*)>5
)
--方式二
select tname from teacher where tno=(
select tno from course where cno=(
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 course 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'
)
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
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.
all:代表括号中的所有成绩
select cno,sno,degree from score where cno='3-105' and degree>all(
select degree from score where cno='3-245'
)ORDER BY degree desc
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 a where degree<(select avg(degree) from score b where b.cno=a.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
)
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 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(*)>1
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(NOW())-year(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 tname,cname from course c,teacher t where c.tno=t.tno and t.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
)
--排序写法
select sno,cno,degree from score ORDER BY degree desc limit 1
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 sno,cno,degree from score where cno=(
select cno from course where cname='计算机导论'
)and sno in(select sno from student where ssex='男')
兼总条贯 知至知终
