Expanding Possible Entities

I'm working on a personal project problem. It's a donation management model. I need 开发者_如何学运维to link donations to entities. For example, the original set of entities that donate are Families, Companies, and Individuals. I want to link donations to these entities and interrelate entities to each other. Is there an example of designing this model where entities could expand and relationships don't get impacted?

Hope this is self-explanatory.

You need to create an entity for donations, contacts, types in the least. A basic idea:

types { id, TypeName } for families, companies, individuals
contacts { id, first name, last name , typeid, add1, addr2 .....}
donations { id, contactID, amount, other fields....}

You could always store the data in one table as structures and then have lookup tables for metadata, like the last time a donor was contacted, and add new data structures at will