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There are three kinds of entity inheritance that represent different ways to map a table or tables to an entity or entities.

Single-Table Inheritance

In single-table inheritance, a single table can be used for more than one entity. The most sure way to do this is to use a column, or a set of columns, that have ordinal values.


When instances of the Cars or the Planes entity are created, one must make sure to set the objType attribute. It is often simplest to have custom EO classes for the entities that can handle the initiation reliably.

Horizontal Inheritance

Vertical Inheritance