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关于MySQL语句建表的总结

2022-09-17 来源:保捱科技网


在写代码之前,需要注意的一个问题是,使用命令行模式写MySQL语句,如果涉及到中文,最好利用 mysql>charset GBK;命令将客户端字符集设置为GBK,这样能保证正确插入和读取中文(数据库端字符集可以是gb2312,GBK,utf8等支持中文的字符集).

如果是利用Mysql 提供的 MySQL Query Browser 工具来写脚本,建议先在ultra edit等文本工具(最好别用记事本,因为可能有字符编码问题,推荐ultra edit)将代码写好,然后再粘贴到QueryBrowser 的Script Tab 中一并执行,因为QueryBrowser对中文的支持有bug,无法正确的输入中文,因此要先在别处写好。

写了几个表,里面包括外键主键的设置,建表语句如下:

USE testdatabase;

CREATE TABLE class (

class_id INTEGER UNSIGNED AUTO_INCREMENT PRIMARY KEY,

class_name VARCHAR(40)

);

CREATE TABLE student (

student_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,

PRIMARY KEY(student_id),

student_name varchar(40),

class_id INTEGER UNSIGNED,

CONSTRAINT FK_student_class FOREIGN KEY(class_id) REFERENCES

class(class_id) ON DELETE CASCADE ON UPDATE CASCADE

);

CREATE TABLE lession(

lession_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,

PRIMARY KEY (lession_id),

lession_name varchar(40)

);

CREATE TABLE core(

core_id INTEGER UNSIGNED AUTO_INCREMENT,

lession_id INTEGER UNSIGNED NOT NULL,

student_id INTEGER UNSIGNED NOT NULL,

core FLOAT,

close_status INTEGER DEFAULT 0,

CONSTRAINT PK_core PRIMARY KEY(

core_id

),

CONSTRAINT FK_core_lession FOREIGN KEY(lession_id) lession(lession_id),

CONSTRAINT FK_core_student FOREIGN KEY(student_id) student(student_id)

ON DELETE CASCADE

);

CREATE TABLE teacher(

teacher_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,

PRIMARY KEY(teacher_id),

REFERENCES

REFERENCES

teacher_name varchar(40)

);

CREATE TABLE teachlession(

teachlession_id INTEGER PRIMARY KEY AUTO_INCREMENT,

lession_id INTEGER UNSIGNED,

teacher_id INTEGER UNSIGNED,

CONSTRAINT FK_teachlession_lession FOREIGN KEY(lession_id) REFERENCES lession(lession_id)

ON DELETE CASCADE,

CONSTRAINT FK_teachlession_teacher FOREIGN KEY(teacher_id) REFERENCES teacher(teacher_id)

ON DELETE CASCADE

);

CREATE TABLE sySUSEr(

sySUSEr_id INTEGER UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,

sySUSEr_name VARCHAR(40),

sySUSEr_password VARCHAR(40),

sySUSEr_role INTEGER,

foreign_id INTEGER

);

/*这是指定表和列的字符集方式创建表*/

use testdatabase;

drop table if exists chartable;

create table chartable(

name varchar(30) character set utf8 collate utf8_general_ci

)character set latin1 collate latin1_danish_ci;

insert into chartable values('我们的世界');

一点总结:

1. 建表语句的顺序必须符合各个表之间的关系,比如主表应该在与之有外键关系的表之前建立。

2.关于外键的声明,两个字段的类型必须相同。

3.注意代码的编码格式和数据库字符集项符合。

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