创建外键的MySQL语法 [英] MySQL Syntax in creating Foreign Key

问题描述

$ b

 创建表部门
（
 departmentID int not null auto_increment主键，
 name varchar（30）
）type = InnoDB; 
 
创建表员工
（
 employeeID int not null auto_increment主键，
名称varchar（80），$ b $ job varchar（30），
 departmentID int not null引用department（departmentID）
）type = InnoDB; 
  

解决方案

MySQL接受它（不抱怨关于语法），但实际上并没有创建外键。

要创建这个外键，运行这个命令：

  ALTER TABLE雇员ADD CONSTRAINT fk_department FOREIGN KEY（departmentID）REFERENCES department（departmentID）; 
  

Is this syntax correct in creating a Foreign Key?

create table department
(
  departmentID int not null auto_increment primary key,
  name varchar(30)
) type=InnoDB;

create table employee
(
  employeeID int not null auto_increment primary key,
  name varchar(80),
  job varchar(30),
  departmentID int not null references department(departmentID)
) type=InnoDB;

解决方案

It looks like MySQL accepts it (doesn't complain about the syntax) but the foreign key is not actually created.

To create this foreign key, run this command:

ALTER TABLE employee ADD CONSTRAINT fk_department FOREIGN KEY (departmentID) REFERENCES department (departmentID);

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