How can I use Mongoid and ActiveRecord in parallel in Rails 3?

Question

I\'m using rails 3, and began my application with ActiveRecord. Now, I have many models, and the relations are starting to get complicated, and some could be more simply expres

Answer 1

i created a module for spoofing the relation in active record models.

module MongoRelations
  def belongs_to_mongo(name, options = {})
    id_name = "mongo_#{name}_id".to_sym
    mongo_model = options[:through] || "Mongo::#{name.to_s.camelize}".constantize

    define_method(name) do
      id = send(id_name)
      mongo_model.find(id) if id.present?
    end

    define_method("#{name}=") do |value|
      send("#{id_name}=".to_sym, value.try(:id).to_s)
    end
  end
end

In my SQL table, I name my mongo relations using the convention mongo_XXX_id, instead of XXX_id

I also namespace all my mongo models under Mongo::

in my active record model

class Foo < ActiveRecord::Base
    belongs_to_mongo :XXX
end

which allows

Foo.new.XXX = Mongo.find('123')
Foo.XXX

or

Foo.new.XXX_id = '123'
Foo.XXX