At 11:19 PM 6/08/2008, you wrote:

>Each supplier owns many farms. One farm can only be owned by one supplier

Ah, so suppliers OWN farms, not supply them. ;-) And farms PRODUCE products, not get them from suppliers.

>> I think SUPP_CODE does not belong in the FARM record at all, but in
>> a separate intersection table between FARM and SUPPLIER, that has
>> FKs to both tables.
>>
>This is a one-to-many relationship and I have a direct relationship
>using the supplier code as the key in the farm table.
>
>supplier
>supp_code
> 1
>farm
>supp_code farm_code
>1 101
>1 102
>1 103
>supplier
>supp_code
> 2
>farm
>supp_code farm_code
>2 201
>2 202
>2 203
>
>It doesn't make sense to have a third table referencing these two,
>does it?

Not with that relationship. From the names of the entities I thought that this should be MANY:MANY (farms as consumers of suppliers' products).

But do think about that PK on farm. It should be FARM_CODE on its own and SUPP_CODE should be a FK to SUPPLIER. (This smells like inherited Paradox hierarchical keys....) The two fields should be constrained to be unique - as a UNIQUE constraint if you need to refer to the combination as a key; otherwise a unique index would suffice.

./heLen