VPM recognizes only relations between Foreign Keys and Primary Keys. As does xCase, the ERD tool we use). As do VFP persistent relations (http://support.microsoft.com/kb/130243).

Of course, Chris Date (who with Codd created relational theory) does point out that Primary Key is actually not part of relational theory. Technically, it's an implementation specific. Oh well, I live in the world of implementation.

Hank

>>http://en.wikipedia.org/wiki/Unique_key
>>
>>From the entry: "Depending on its design, a table may have arbitrarily many unique keys but at most one primary key."
>>
>Thanks a lot for the link. From this link I see also
>
>Unique keys as well as primary keys can be referenced by foreign keys.
>
>In any case, now I'm not clear what to do - I can not change all existing tables, but using name as a PK doesn't sound like a good idea to me.