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?

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Hope this is self-explanatory.

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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....}

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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