A key question: Can more than one company supply the same product or is each record in Products always unique to a given company that supplies it?
Thanks for the links, David. I'll read them this evening.
Phil: the product can only be supplied by one company. How does this affect the use of fields? Thanks!
It affects the relationships that you might set up between products and companies. In many businesses, a company can supply many products and a given product can be supplied by more than one company. Such is called a many to many relationship. But you do not have that, you have one company to possibly many products, a one to many relationship:
Companies::__pkCompanyID = Products::_fkCompanyID
For an explanation of the notation that I am using, see the first post of: Common Forum Relationship and Field Notations Explained