mysql操作-外键

1.创建外键,关联两个表

create table score(
    id int not null auto_increment,
    subject char(32) not null,
    stu_id int not null,
    primary key(id),
    key fk_stu_key (stu_id),
    constraint fk_stu_key foreign key (stu_id) references student (stu_id));