Multiple table inheritance Rails and activerecord - ruby-on-rails-3

Question

I'm trying to implement Multiple Table Inheritance with ActiveRecord. Looks like all the available gems are pretty old. Am I missing something? Is there any "native" way to implement this with activerecord?
I'm using Rails 3.2.3 and activerecord 3.2.1

Answer 1

Rails 6.1+ delegated type
Rails 6.1 added a "native" way to implement Multiple Table Inheritance via delegated type.
See the corresponding PR for details.
With this approach, the "superclass" is a concrete class that is represented by its own table, where all the superclass attributes that are shared amongst all the "subclasses" are stored. And then each of the subclasses have their own individual tables for additional attributes that are particular to their implementation. This is similar to what's called multi-table inheritance in Django, but instead of actual inheritance, this approach uses delegation to form the hierarchy and share responsibilities.

Answer 2

Single Table Inheritance (where each Car and Truck share one database)
class Vehicle < ActiveRecord
end
class Car < Vehicle
end
class Truck < Vehicle
end
In your case you are not sharing the database but rather the functions. You should then write a module and include it in each model
class Car < ActiveRecord
extend VehicleFinders
end
class Truck < ActiveRecord
extend VehicleFinders
end
module VehicleFinders
def find_purchased
#...
end
end
So in extend module's method are class method on that calling class.include module's methods are instance method for object of calling class
This might be a good read for you http://raysrashmi.com/2012/05/05/enhance-rails-models