Primary -- foreign keys

Hi

I am trying to understand why would anyone want to create the following:

create table abc
(

    x integer primary key,
    y char(20),
    foreign key (x) references abc(x)
);

What's being accomplished by creating a forein key which references a primary key of the same table??? Primary and foreign keys are on the same column of the same table????

Thanks

Keith Received on Fri Aug 10 2001 - 08:50:44 CDT