app/models/spree/product_resource.rb
module Spree
class ProductResource < ActiveRecord::Base
self.table_name = 'spree_product_resources'
belongs_to :product, class_name: 'Spree::Product', :foreign_key => :product_id
belongs_to :resource, class_name: 'Refinery::Resource', :foreign_key => :resource_id
end
end