Table Design Advice - normalizing

I have potentially 4 entities which are all of the same "master entity" type (if you can call it that). Each entity shares the same subset of 6 fields, but 3 of the entities have additional fields.

ex. Entity SimpleFP : fields - LongDesc,ShortDesc,ActID,Qty,Year,Month Entity ComplexFP: fields -
LongDesc,ShortDesc,ActID,Qty,Year,Month,UnitPrice, ISDate.

The proper thing to do, I believe, is to create 4 tables, one for each entity. However since they share so much in common, I was wondering if there was an efficient way that I could create 1 table for all entities? It seems like a waste to have four tables.

Could anyone provide suggestions on this issue?

Thank you,
April Received on Mon Oct 22 2001 - 21:44:29 CEST