Referential Integrity

[Lani2000]

Can a DB table have a foreign key and not a primary key? I have a key in one table that references a primary key in another table.

[Lani2000]

Also can you have a primary key that references a primary key in another table?

Thank you

[slimdave]

A foreign key can only exist if there is a primary key to reference. The PK referenced by the FK can be on a different table (as is usually the case), but could be on the same table as the FK (so the table is "self-referential").

A table does not need to have a PK in order to have FK's (this is often the case with data warehouse fact tables).

A PK does not reference another PK -- PK's don't reference other contrainsts at all, in the way that FK's do.