Database Table Inheritance

Question

Is it possible for a table to inherit on-to-many sub tables? (I think thats how its meant to be worded :P) In others words:

 PersonBase can be PersonA and/or PersonD and/or PersonC

However in this particular case it needs to be possible for PersonBase to exist multiple times as PersonD (there are reasons for it), could I do it this way? Or should I create another table say TableD such that PersonBase is a PersonD which has a one to many relationship with TableD. However I would prefer to be able to do it so that PersonBase can be multiple PersonDs if possible.

Thanks All

P.S. I apologize if my question seems naive.

• user166390: SQL has no such concept itself. However, many ORMS add such mappings, as do OORDMBS. Looking at how, say, this is handled in both PostgreSQL and Hibernate may be beneficial.
• Heinrich: @Matthew Cox, Sorry I don't think so, multiple inheritance allows one to inherit from multiple tables, yes? What I need is for PersonBase to exists multiple times in PersonD, in other words say we have John Dow, what I would need is for John Dow to be able to exists more than once in PersonD, that if I search for John Dow(ID 5) it might possibly return two entries from PersonD. Sorry I should probably rephrase the question a bit :)
• Damir Sudarevic: This seems to me like duplicating rows? If they were all in one table John D. would exists in two rows?

Answer 1

postgresql has actual table inheritance just like OOP. A Base table columns are inherited by "sub-tables" it also supports even multiple base classes.

Answer 2

I think what you describe in the first case, between PersonBase (supertype) and PersonA, PersonC (subtype), are 1:1 relationships (supertype/subtype), while in the second case, between PersonBase and PersonD, is a 1:n relationship.