数据库查询练习题

mysql查询练习题

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）。表结构及数据如下，请完成题目。

#建学生信息表student
sno varchar(20) not null primary key,
sname varchar(20) not null,
ssex varchar(20) not null,
sbirthday datetime,
class varchar(20)
#建立教师表

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
#建立课程表course

cno varchar(20) not null primary key,
cname varchar(20) not null,
tno varchar(20) not null,
foreign key(tno) references teacher(tno)
#建立成绩表

sno varchar(20) not null,
foreign key(sno) references student(sno),
cno varchar(20) not null,
foreign key(cno) references course(cno),
degree decimal,
primary key(sno,cno)
#添加学生信息
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
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
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
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('103','6-166','85');
insert into score values('105','6-166','79');
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。

	SELECT student.sname, student.ssex, student.class FROM student;

2、 查询教师所有的单位即不重复的Depart列。

	SELECT teacher.depart FROM teacher GROUP BY teacher.depart;
	
	SELECT DISTINCT teacher.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 score.degree >= 60 AND score.degree <= 80;

5、 查询Score表中成绩为85，86或88的记录。

	SELECT * FROM score WHERE score.degree = 85 OR score.degree = 86 OR score.degree = 88;

6、 查询Student表中“95031”班或性别为“女”的同学记录。
	
	SELECT * FROM student WHERE student.class = 95031 OR student.ssex = 女;
	
7、 以Class降序查询Student表的所有记录。

	SELECT * FROM student ORDER BY student.class DESC;

8、 以Cno升序、Degree降序查询Score表的所有记录。

	SELECT * FROM score ORDER BY score.cno ASC, score.degree DESC;

9、 查询“95031”班的学生人数。
	
	SELECT student.class, count(*) FROM student GROUP BY student.class HAVING student.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
	score.sno,
	score.cno
FROM
	score
WHERE
	score.degree = (SELECT MAX(degree) FROM score)

11、 查询每门课的平均成绩。

	SELECT Avg(score.degree), score.cno FROM score GROUP BY score.cno;

12、查询Score表中至少有2名学生选修的并以3开头的课程的平均分数。
	
SELECT
	Avg(score.degree),
	Count(score.cno),
	score.cno
FROM
	score
GROUP BY
	score.cno
HAVING
	Count(score.cno) >= 2
AND score.cno LIKE '3%'

13、查询分数大于70，小于90的Sno列。

	SELECT score.sno FROM score WHERE score.degree > 70 AND score.degree < 90;

14、查询所有学生的Sname、Cno和Degree列。

	 SELECT student.sname, course.cno, score.degree FROM student LEFT JOIN score ON score.sno = student.sno LEFT JOIN course ON score.cno = course.cno;
	 
	 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 student.sno, course.cname, score.degree FROM student LEFT JOIN score ON score.sno = student.sno LEFT JOIN course ON score.cno = course.cno;
	
	select Sno,Cname,degree from Score join Course on Course.Cno=Score.Cno;
	
16、查询所有学生的Sname、Cname和Degree列。 

	SELECT student.sname, course.cname, score.degree FROM student LEFT JOIN score ON score.sno = student.sno LEFT JOIN course ON score.cno = course.cno;

17、查询“95033”班学生的平均分。

	SELECT Avg(score.degree) FROM student INNER JOIN score ON score.sno = student.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(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’)

现查询所有同学的Sno、Cno和rank列。

	SELECT score.sno, score.cno, grade.rank FROM score INNER JOIN grade ON score.degree >= grade.low AND score.degree <= 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 student INNER JOIN score ON score.sno = student.sno INNER JOIN course ON score.cno = course.cno 
	AND course.cno = '3-105' AND score.degree > (SELECT score.degree FROM score WHERE score.sno=109 AND score.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
	student,
	Score
WHERE
	student.Sno = Score.Sno
AND Score.Degree > (
	SELECT
		Degree
	FROM
		Score
	WHERE
		Cno = '3-105'
	AND Sno = '109'
);

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
	student.sno,
	student.sname,
	student.sbirthday
FROM
	student
WHERE
	YEAR (sbirthday) = (
		SELECT
			YEAR (sbirthday)
		FROM
			student
		WHERE
			student.sno = 108
		OR student.sno = 101
	)

23、查询“张旭“教师任课的学生成绩。
		
	SELECT score.degree FROM score INNER JOIN teacher ON teacher.tname = '张旭' INNER JOIN course ON course.tno = teacher.tno AND score.cno = course.cno;
	

24、查询选修某课程的同学人数多于5人的教师姓名。

	SELECT teacher.tname, Count(teacher.tno) FROM teacher INNER JOIN course ON course.tno = teacher.tno 
	INNER JOIN score ON score.cno = course.cno GROUP BY course.cno HAVING Count(teacher.tno) > 5;

25、查询95033班和95031班全体学生的记录。

	SELECT * FROM student WHERE student.class = 95033 OR student.class = 95031;

26、 查询存在有85分以上成绩的课程Cno。

	SELECT score.cno FROM score where score.degree > 85;

27、查询出“计算机系“教师所教课程的成绩表。

SELECT
	score.sno,
	score.cno,
	score.degree
FROM
	score
INNER JOIN course ON score.cno = course.cno
INNER JOIN teacher ON course.tno = teacher.tno
AND teacher.depart = '计算机系';
	
	
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'
			)
	)

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 a
WHERE
	Prof NOT IN (
		SELECT
			Prof
		FROM
			Teacher b
		WHERE
			a.Depart != b.Depart
	);

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。

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;

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
	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
	);

31、 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,tbirthday as birthday from Teacher

32、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,tbirthday as birthday 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。

SELECT
	Sno,
	Cno,
	Degree
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
WHERE
	Tname IN (
		SELECT DISTINCT
			Tname
		FROM
			Teacher,
			Course,
			Score
		WHERE
			Teacher.Tno = Course.Tno
		AND Course.Cno = Score.Cno
	)

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 DISTINCT
			Tname
		FROM
			Teacher,
			Course,
			Score
		WHERE
			Teacher.Tno = Course.Tno
		AND Course.Cno = Score.Cno
	)

36、查询至少有2名男生的班号。

	SELECT student.class FROM student WHERE student.ssex = '男' GROUP BY student.class HAVING count(*) >= 2;

37、查询Student表中不姓“王”的同学记录。

	SELECT * FROM student WHERE student.sname NOT LIKE '王%';

38、查询Student表中每个学生的姓名和年龄。

SELECT
	student.sname,
	YEAR (NOW()) - YEAR (sbirthday) as age
FROM
	student;

39、查询Student表中最大和最小的Sbirthday日期值。

	SELECT Max(student.sbirthday), Min(student.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
	student.class DESC,
	YEAR(NOW())-YEAR(sbirthday)DESC;

41、查询“男”教师及其所上的课程。

	SELECT course.cname FROM teacher LEFT JOIN course ON course.tno = teacher.tno WHERE teacher.tsex = '男';
	
42、查询最高分同学的Sno、Cno和Degree列。

	SELECT score.sno, score.cno, score.degree FROM score WHERE score.degree = (SELECT Max(score.degree) FROM score);

43、查询和“李军”同性别的所有同学的Sname。

	SELECT student.sname FROM student WHERE student.ssex = (SELECT ssex FROM student WHERE sname='李军') AND '李军' NOT IN ( student.sname);

44、查询和“李军”同性别并同班的同学Sname。

	SELECT student.sname FROM student WHERE student.ssex = (SELECT ssex FROM student WHERE sname='李军') AND student.class=(SELECT class FROM student WHERE sname='李军')
	AND '李军' NOT IN ( student.sname);

45、查询所有选修“计算机导论”课程的“男”同学的成绩表。

	SELECT score.sno,score.cno,score.degree FROM score INNER JOIN course ON score.cno = course.cno INNER JOIN student ON score.sno = student.sno 
	WHERE student.ssex = '男' AND course.cname =  '计算机导论';	

46、查询学习过3-105并且也学过3-245的同学学号、姓名。

SELECT
	student.sno,
	student.sname
FROM
student
WHERE
student.sno in
(
		SELECT
			score.sno
		FROM
			score
		WHERE
			score.cno = '3-105'
	)
and student.sno in(
	SELECT
		score.sno
	FROM
		score
	WHERE
		score.cno = '3-245'
)

	
47、查询所有课程成绩均小于85分的学生学号、姓名。

	SELECT student.sno, student.sname FROM student INNER JOIN score ON score.sno =student.sno WHERE score.degree < 85 
	GROUP BY score.sno HAVING count(student.sno) = 2;
	
	SELECT student.sno, student.sname FROM student INNER JOIN score ON score.sno =student.sno
	GROUP BY score.sno HAVING  MAX(score.degree) < 85 ;