Re: Relating Tables if Auto Increment Interger is Primary Key

[Peter Brawley]

> PK and the FK must be the same

Not quite. FK must exactly type-match the PK it references. For example ...

drop table if exists b,a;
create table a(
  aid int unsigned primary key auto_increment 
);
create table b(
  bid int unsigned primary key auto_increment, 
  aid int unsigned,
  foreign key(aid) references a(aid) on delete cascade on update cascade
);