SQL语句练习45题（从第11题开始）

CREATE TABLE student
(sno VARCHAR(3) NOT NULL,
sname VARCHAR(4) NOT NULL,
ssex VARCHAR(2) NOT NULL,
sbirthday DATETIME,
class VARCHAR(5));

CREATE TABLE course
(cno VARCHAR(5) NOT NULL,
cname VARCHAR(10) NOT NULL,
tno VARCHAR(10) NOT NULL
);

CREATE TABLE score(
sno VARCHAR(3) NOT NULL,
cno VARCHAR(5) NOT NULL,
degree NUMERIC(10, 1) NOT NULL
);

CREATE TABLE teacher
(tno VARCHAR(3) NOT NULL,
tname VARCHAR(4) NOT NULL, tsex VARCHAR(2) NOT NULL,
tbirthday DATETIME NOT NULL, prof VARCHAR(6),
depart VARCHAR(10) NOT NULL);

INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (108 ,'曾华' ,'男' ,'1977-09-01',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (105 ,'匡明' ,'男' ,'1975-10-02',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (107 ,'王丽' ,'女' ,'1976-01-23',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (101 ,'李军' ,'男' ,'1976-02-20',95033);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (109 ,'王芳' ,'女' ,'1975-02-10',95031);
INSERT INTO STUDENT (SNO,SNAME,SSEX,SBIRTHDAY,CLASS) VALUES (103 ,'陆君' ,'男' ,'1974-06-03',95031);

INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-105' ,'计算机导论',825);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('3-245' ,'操作系统' ,804);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('6-166' ,'数据电路' ,856);
INSERT INTO COURSE(CNO,CNAME,TNO)VALUES ('9-888' ,'高等数学' ,100);

INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-245',86);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-245',75);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-245',68);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (103,'3-105',92);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (105,'3-105',88);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (109,'3-105',76);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'3-105',64);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'3-105',91);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'3-105',78);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (101,'6-166',85);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (107,'6-106',79);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'6-166',81);

INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (804,'李诚','男','1958-12-02','副教授','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (856,'张旭','男','1969-03-12','讲师','电子工程系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (825,'王萍','女','1972-05-05','助教','计算机系');
INSERT INTO TEACHER(TNO,TNAME,TSEX,TBIRTHDAY,PROF,DEPART) VALUES (831,'刘冰','女','1977-08-14','助教','电子工程系');

创建好的表如下：
table.student

table.course

table.teacher

table.score

11、查询‘3-105’号课程的平均分

select AVG(score.degree)
from score
where score.cno = '3-105';

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(score.degree)
from score
where score.cno in (
select score.cno
from score
where score.cno like '3-%'
group by score.cno
having count(score.cno) >= 5);

13、查询最低分大于70，最高分小于90的Sno列

select score.sno
from score
group by score.sno
having MAX(score.degree) < 90 and MIN(score.degree) > 70;

14、查询所有学生的Sname、Cno和Degree列

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

15、查询所有学生的Sno、Cname和Degree列

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

16、查询所有学生的Sname、Cname和Degree列

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

17、查询“95033”班所选课程的平均分

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

18、假设使用如下命令建立了一个grade表：
create table grade(low INTEGER,upp INTEGER,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');
commit;
现查询所有同学的Sno、Cno和rank列

创建表如下：

第一种方法：
select sno,cno,degree,rank
from score join grade
where degree between low and upp;
第二种方法：
select *
from score join grade
on degree > low
and degree <= 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 score.cno = '3-105' and degree >
(select degree
from score
where sno = '109'and cno = '3-105');

20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录

select sno,score.cno,degree,cmax
from score join (
select cno,max(degree) as cmax
from score
group by cno
) as mc
on degree < cmax and mc.cno = score.cno
where sno in (
select sno
from score
group by sno
having count(*) > 1);

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 degree,sname
from score join course
on score.cno = course.cno
join teacher
on course.tno = teacher.tno
join student
on score.sno = student.sno
where teacher.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 score join course
on score.cno = course.cno
join teacher
on course.tno = teacher.tno
group by score.cno
having COUNT(*) > 5;

25、查询95033班和95031班全体学生的记录

select *
from score join student
on score.sno = student.sno
where class = '95033' || class = '95031';

26、查询存在有85分以上成绩的课程Cno

select score.cno
from score
where degree > 85
group by cno;

27、查询出“计算机系“教师所教课程的成绩表

select sname,cname,degree
from score join course
on score.cno = course.cno
join teacher
on course.tno = teacher.tno
join student
on score.sno = student.sno
where depart = '计算机系';

28、查询在“计算机系”中, 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

29和30差不多 就写一个了

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 a
where cno = '3-105'
and a.degree > (
select b.degree
from score b
where b.cno = '3-245' and a.sno = b.sno
);

31、查询所有教师和同学的name、sex和birthday

select sname,ssex,sbirthday
from student union (select tname,tsex,tbirthday
from teacher);

32、查询所有“女”教师和“女”同学的name、sex和birthday

select sname,ssex,sbirthday
from student
where ssex = '女'
union (select tname,tsex,tbirthday
from teacher
where tsex = '女');

33、查询成绩比该课程平均成绩低的同学的成绩表

第一种方法：
select student.sname,course.cname,score.degree
from student join score
on student.sno = score.sno
join course
on score.cno = course.cno
where score.degree< any (select AVG(score.degree)
from score
group by score.cno
having AVG(score.degree));
第二种方法：
select *
from score a
where a.degree<(
select avg(degree) from score b
where a.cno = b.cno
);

34、查询所有任课教师的Tname和Depart

select tname,depart
from teacher join course
on 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 tname not in (select tname
from teacher join course
on teacher.tno = course.tno);

36、查询至少有2名男生的班号

select class
from student
group by class
having count(ssex = '男') >= 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,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) as 最小 ,min(sbirthday) as 最大
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 asc;

41、查询“男”教师及其所上的课程

select course.cname,tname
from course join teacher
on course.tno = teacher.tno
where tsex = '男';

42、（1）查询最高分同学的Sno、Cno和Degree列

select sno,cno,degree
from score
where score.degree in (select MAX(degree)
from score
group by cno);

42、（2）查询每门课的前三名

select a.sno,a.cno,a.degree
from score a left join score b
on a.cno = b.cno and a.degree < b.degree
group by a.sno,a.cno,a.degree
HAVING COUNT(b.sno)❤️
ORDER BY a.cno,a.degree desc ;

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')
and sname not in ('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')
and sname not in ('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 sname,degree
from student join score
on score.sno = student.sno
join course
on course.cno = score.cno
where cname = '计算机导论' and ssex = '男';