class Movie < ActiveRecord::Base
  has_many :reviews
  def inspect ; "#{title} (#{rating}) - #{release_date.strftime('%D')}" ; end
  scope :for_kids, :conditions => ['rating IN (:ratings)', :ratings => %w(G PG)]
  scope :with_good_reviews, lambda { |cutoff|
    joins(:reviews).
      group(:movie_id).
      having("AVG(reviews.potatoes) > #{cutoff}")
  }
end