允许用户使用accepts_nested_attributes_for选择正确答案？

Question

我有轨道关系：

class Quiz < ActiveRecord::Base
  has_many :questions, dependent: :destroy
  accepts_nested_attributes_for :questions,
                            reject_if: proc { |a| a[:content].blank? },
                            allow_destroy: true
end

class Question < ActiveRecord::Base
  belongs_to :quiz
  has_many :answers, dependent: :destroy
  accepts_nested_attributes_for :answers,
                                reject_if: proc { |a| a[:content].blank? },
                                allow_destroy: true
end

class Answer < ActiveRecord::Base
  belongs_to :question
end

当用户处于Quiz＃edit或Quiz＃new时，如何构建模型，他们可以选择哪个答案（带单选按钮）是正确的答案？

Answer 1

在answers表格中，添加名为＆＃39; is_correct_answer＆＃39;的其他属性。这只适用于一种组合。