Combine MongoDB and Postgresql in Rails?

Is it possible to co开发者_如何学编程mbine AR with MongoMapper/MongoID?

If so, are there tutorials/documentations for this?

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Yes, it is a piece of cake. There really isn't anything special you need to do, just make models with the different adapters accordingly. This is an example Mongoid document:

class Project
  include Mongoid::Document
end

For comparison, here is activerecord:

class BillingEntry < ActiveRecord::Base
end

Just make sure not to mix them up. For example, don't include mongoid on a class that inherits from ActiveRecord::Base. I recommend Rails 3, as it's probably going to release this week, and the RCs have been really solid so far.

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Yes it's possible. Can you please be more specific on what you want to achieve? It's even easier if you use Rails 3 because mongoid and ActiveRecords uses ActiveModel as the interface.