Rails custom validation - Only one record can be true

Question

I\'m trying to write a validation where only one record can be true. I have a \'game\' model with an \'active\' boolean column, only one game can be active at any time, so if so

Answer 1

Try using the exists? method. Also, add the error using the add method.

validate :active_game
scope :active, where(active: true)

  def active_game
    if active && Game.active.where("id != ?", id).exists?
       errors.add(:name, "a game is already active!")
    end
  end