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authorSteve Klabnik <steve@steveklabnik.com>2012-09-17 22:03:34 +0300
committerSteve Klabnik <steve@steveklabnik.com>2012-09-17 22:03:34 +0300
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Add note about inheretance and poly associations.
This note came about due to discussion in #6786.
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!images/polymorphic.png(Polymorphic Association Diagram)!
+Polymorphic associations can get tricky with inheritance. If you need
+an inheritance relationship in your ActiveRecord models, you should use
+Single Table Inheritance instead.
+
h4. Self Joins
In designing a data model, you will sometimes find a model that should have a relation to itself. For example, you may want to store all employees in a single database model, but be able to trace relationships such as between manager and subordinates. This situation can be modeled with self-joining associations: