更新时间:2022-11-08 18:40:57
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;
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);