Union Query in AR

union_queries.rb

module UnionQuery
  extend ActiveSupport::Concern
  
  included do
    
    def self.union(query1, query2, params={}, type='all')
      find_by_sql "#{query1.to_sql} UNION #{type} #{query2.to_sql}", params
    end
    
    def self.unite_with(query2)
      union scoped, query2 
    end
  end
  
end

class Thing1 < ActiveRecord::Base
  scope :unite_me, lambda { select('name') }
  include UnionQuery
end

class Thing2 < ActiveRecord::Base
  scope :also_unite_me, lambda { select('name') }
end

Thing1.union(Thing1.unite_me, Thing2.also_unite_me)
Thing2.select('name').unite_with Thing2.select('name')