注:基于(https://blog.csdn.net/xiaosa_kun/article/details/84868547)所修改,修改查询语句的第16,27。
1.新建数据库
CREATE DATABASE school;
设有一个数据库school,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。
创建学生表
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)
) ENGINE = innodb CHARSET = utf8;
创建教师表
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
) ENGINE = innodb CHARSET = utf8;
创建课程表
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)
) ENGINE = innodb CHARSET = utf8;
创建成绩表
CREATE TABLE score (
sno varchar(20) NOT NULL,
FOREIGN KEY (sno) REFERENCES student (sno),
cno varchar(20) NOT NULL,
FOREIGN KEY (cno) REFERENCES course (cno),
degree decimal NOT NULL
) ENGINE = innodb CHARSET = utf8;
2.插入数据库
插入学生表数据
use student;
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);
插入教师表数据
use teacher;
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');
插入课程表数据
use course;
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' ,831);
插入成绩表数据
use score;
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,'9-888',79);
INSERT INTO SCORE(SNO,CNO,DEGREE)VALUES (108,'6-166',81);
3.查询数据
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 depart
FROM teacher
GROUP BY depart;
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。(between)
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。(in)
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。(排序)
SELECT sno, cno
FROM score
ORDER BY degree DESC;
11、查询每门课的平均成绩。(group by)
SELECT cname, AVG(degree)
FROM score
INNER JOIN course
WHERE course.cno = score.cno
GROUP BY course.cname;
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。(group by having)
SELECT cno, AVG(degree)
FROM score
WHERE cno LIKE '3%'
GROUP BY cno
HAVING COUNT(sno) >= 5;
13、查询最低分大于70,最高分小于90的Sno列。
SELECT sno
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 sname, score.cno, degree
FROM student
INNER JOIN score
WHERE student.sno = score.sno;
15、查询所有学生的Sno、Cname和Degree列。
SELECT student.sno, sname, degree
FROM student
INNER JOIN score
WHERE student.sno = score.sno;
16、查询所有学生的Sname、Cname和Degree列。
select sname,cname,degree
from student
inner join score,course
where
course.cno = score.cno and student.sno = score.sno;
17、查询“95033”班学生的平均分。(选)
SELECT AVG(degree)
FROM student
INNER JOIN score
WHERE class = '95033'
AND student.sno = score.sno;
18、假设使用如下命令建立了一个grade表,并查询所有同学的Sno、Cno和rank列。
create table grade(low int(3),high int(3),rank varchar(20));
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;
select sno,cno,rank
from score
inner join grade
where degree < high and degree >low;
19、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。(选)
SELECT *
FROM score
WHERE degree > (
SELECT degree
FROM score
WHERE sno = '109'
AND cno = '3-105'
);
20、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。(选)
SELECT sno, sname, sbirthday
FROM student, (SELECT year(sbirthday) AS birthyear
FROM student
WHERE sno = 108
) s1
WHERE year(sbirthday) = s1.birthyear;
21、查询“张旭“教师任课的学生成绩。(选)
SELECT tname, cname, sname, degree
FROM teacher, course, student, score
WHERE teacher.tno = course.tno
AND course.cno = score.cno
AND score.sno = student.sno
AND teacher.tname = '张旭';
22、查询95033班和95031班全体学生的记录。(in)
SELECT *
FROM student
WHERE class IN ('95033', '95031');
23、查询存在有85分以上成绩的课程cno.
SELECT cno
FROM score
GROUP BY cno
HAVING MAX(degree) >= 85;
24、查询出“计算机系“教师所教课程的成绩表。(选)
SELECT score.sno, sname, degree
FROM teacher, score, course, student
WHERE teacher.tno = course.tno
AND course.cno = score.cno
AND score.sno = student.sno
AND teacher.depart = '计算机系';
25、查询成绩比该课程平均成绩低的同学的成绩表。(选)
SELECT s.sno, s.cno, s.degree
FROM score AS s, (SELECT cno, AVG(degree) AS avgd
FROM score
GROUP BY cno
) avgs
WHERE s.cno = avgs.cno
AND s.degree < avgs.avgd;
26、查询所有任课教师的Tname和Depart.(选)
SELECT tname, depart
FROM teacher;
27、查询至少有2名男生的班号。(group by having)
SELECT class, COUNT(sname)
FROM student
GROUP BY class
HAVING COUNT(sname) >= 2;
28、查询Student表中不姓“王”的同学记录。(not like)
SELECT *
FROM student
WHERE sname NOT LIKE '王%';
29、查询Student表中每个学生的姓名和年龄。
SELECT sname, 2018 - year(sbirthday) AS age
FROM student;
30、查询Student表中最大和最小的Sbirthday日期值。
SELECT MAX(sbirthday), MIN(sbirthday)
FROM student;
31、以班号和年龄从大到小的顺序查询Student表中的全部记录。
下面两种SQL语句一样的效果,年龄大则出生日期小
SELECT *
FROM student
ORDER BY class DESC, sbirthday ASC;
SELECT *
FROM student
ORDER BY class DESC, sbirthday;
32、查询“男”教师及其所上的课程。
SELECT tname, cname
FROM teacher, course
WHERE teacher.tno = course.tno
AND tsex = '男';
33、查询每一门科目最高分同学的Sno、Cno和Degree列。(选)
SELECT sno, cno, MAX(degree)
FROM score
GROUP BY cno;