Self-Referential PK-FK

[Jenna Klein]

Is it possible to create foreign keys that reference primary keys in the 
same table?

Here's why: I want to create a Staff table and, obviously, some of our 
staff are managers to other people, eventually reaching the CEO. I want to 
create a staff ID that is the PK and then create a manager column that is 
an FK pointing back to that PK.

The only problem would be the CEO but I supposed I could make him have a 
manager of himself.

Thanks for any input.

Jenna