建点表,填点数
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一、建数据表
学生表Student:学号、姓名、性别、出生年月日、班级
mysql> create database selectTest; mysql> show databases; mysql> use selectTest; Database changed mysql> create table student( -> stu_num varchar(20) primary key, -> stu_name varchar(20) not null, -> stu_sex varchar(10) not null, -> stu_birth datetime, -> class varchar(20) -> );
教师表Teacher:教师编号、教师名字、教师性别、出生年月日、职称、所在部门
mysql> create table teacher( -> tea_num varchar(20) primary key, -> tea_name varchar(20) not null, -> tea_sex varchar(10) not null, -> tea_birth datetime, -> tea_prof varchar(20) not null, -> department varchar(20) not null -> );
课程表Course:课程号、课程名称、教师编号
mysql> create table course( -> cour_num varchar(20) primary key, -> cour_name varchar(20) not null, -> tea_num varchar(20) not null, -> foreign key(tea_num) references teacher(tea_num) -> );
成绩表Score:学号、课程号、成绩
mysql> create table score( -> stu_num varchar(20) primary key, -> cour_num varchar(20) not null, -> degree decimal, -> foreign key(stu_num) references student(stu_num), -> foreign key(cour_num) references course(cour_num) -> );
mysql> show tables; +----------------------+ | Tables_in_selecttest | +----------------------+ | course | | score | | student | | teacher | +----------------------+
二、向表中插入数据
mysql> INSERT INTO student VALUES(‘11422‘,‘Baker‘,‘F‘,‘1999-09-22‘,‘114‘); mysql> INSERT INTO student VALUES(‘11423‘,‘Bob‘,‘M‘,‘1998-04-25‘,‘114‘); mysql> INSERT INTO student VALUES(‘11424‘,‘LinJie‘,‘M‘,‘1994-06-12‘,‘114‘); mysql> INSERT INTO student VALUES(‘11425‘,‘XieZhou‘,‘M‘,‘1995-03-11‘,‘114‘); mysql> INSERT INTO student VALUES(‘11426‘,‘MingHui‘,‘F‘,‘1998-08-09‘,‘114‘); mysql> INSERT INTO student VALUES(‘11427‘,‘NanNan‘,‘F‘,‘1995-10-20‘,‘114‘); mysql> INSERT INTO student VALUES(‘11328‘,‘DingQi‘,‘F‘,‘1994-08-15‘,‘113‘); mysql> INSERT INTO student VALUES(‘11215‘,‘JiaWei‘,‘F‘,‘1993-07-28‘,‘112‘);
mysql> INSERT INTO teacher VALUES(‘0435‘,‘LiMei‘,‘F‘,‘1983-02-24‘,‘prof‘,‘Computer‘); mysql> INSERT INTO teacher VALUES(‘0436‘,‘MaDi‘,‘F‘,‘1984-01-23‘,‘assist‘,‘Bio‘); mysql> INSERT INTO teacher VALUES(‘0437‘,‘LiZhe‘,‘F‘,‘1974-01-23‘,‘prof‘,‘Econ‘); mysql> INSERT INTO teacher VALUES(‘0438‘,‘ShaoGuoYing‘,‘F‘,‘1985-06-17‘,‘prof‘,‘Math‘);
mysql> INSERT INTO course VALUES(‘3-105‘,‘OS‘,‘0435‘); mysql> INSERT INTO course VALUES(‘1-245‘,‘Math‘,‘0438‘); mysql> INSERT INTO course VALUES(‘2-271‘,‘Circuit‘,‘0435‘); mysql> INSERT INTO course VALUES(‘4-321‘,‘Bio‘,‘0436‘);
mysql> INSERT INTO score VALUES(‘11422‘,‘3-105‘,‘92‘); mysql> INSERT INTO score VALUES(‘11423‘,‘1-245‘,‘84‘); mysql> INSERT INTO score VALUES(‘11424‘,‘4-321‘,‘75‘); mysql> INSERT INTO score VALUES(‘11425‘,‘2-271‘,‘89‘); mysql> INSERT INTO score VALUES(‘11426‘,‘1-245‘,‘61‘); mysql> INSERT INTO score VALUES(‘11427‘,‘1-245‘,‘78‘); Query OK, 1 row affected (0.07 sec) mysql> INSERT INTO score VALUES(‘11426‘,‘2-271‘,‘82‘); ERROR 1062 (23000): Duplicate entry ‘11426‘ for key ‘PRIMARY‘ mysql> INSERT INTO score VALUES(‘11423‘,‘2-271‘,‘75‘); ERROR 1062 (23000): Duplicate entry ‘11423‘ for key ‘PRIMARY‘
修改表score中的主键为联合主键:
mysql> drop table score;
mysql> create table score( -> stu_num varchar(20) not null, -> cour_num varchar(20) not null, -> degree decimal, -> foreign key(stu_num) references student(stu_num), -> foreign key(cour_num) references course(cour_num), -> primary key(stu_num,cour_num) -> );
插入数据后:
mysql> select * from score; +---------+----------+--------+ | stu_num | cour_num | degree | +---------+----------+--------+ | 11422 | 3-105 | 92 | | 11423 | 1-245 | 84 | | 11423 | 2-271 | 75 | | 11424 | 4-321 | 75 | | 11425 | 2-271 | 89 | | 11426 | 1-245 | 61 | | 11426 | 2-271 | 82 | | 11427 | 1-245 | 78 | +---------+----------+--------+
04‘08‘‘
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