class Street < AR::Base
  belongs_to :city

  def get_county
    self.city.county
  end
end

class City < AR::Base
  has_many :streets
  belongs_to :county
end

class County < AR::Base
  has_many :cities

  def streets_for_city(city_name)
    self.cities.find_by_name(city_name, :include => :streets).streets
  end

  def all_streets
    City.find(:all, :conditions => {:county_id => self.id}, :include => :streets).collect(&:streets).flatten
  end
end