建点表,填点数

Posted direwolf22

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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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