[jonboy582]

I am having an issue with normalisation.

Pretty much the problem is, I have a table which has customer details and a PK of customer ID.

A customer could be both a seller or a buyer as the database is being made for a middle man (in this case an auction house).

The invoice displays the buyer ID and seller ID. Can I have the same foreign key twice in the same table?

i.e.
Lot_ID *PK
~all the details of item~
customer_ID
customer_ID

and just give them different aliases?

Thanks Jon