Rails Model "random_record" Helper

random_record.rb

class ApplicationRecord

  def self.random
    max = maximum(primary_key)

    return if max.nil?

    find_random = lambda do
      order(primary_key).find_by(primary_key => (rand(max)..))
    end

    record = find_random.call
    record = find_random.call until record.present?
    record
  end

end

I've only ever used this as a toy method in dev/test environments, but I could see it being useful in production environments that have buttons like "Play a Random Song".