嵌套表单未知属性：question_id

Question

我有两个模型：

class Question < ActiveRecord::Base
  has_many :answers, :dependent => :destroy
  accepts_nested_attributes_for :answers
end

class Answer < ActiveRecord::Base
  belongs_to :question
end

以下控制器：

class QuestionsController < ApplicationController

  def new
    @question = Question.new  
    4.times { @question.answers.build }
  end

end

当我尝试加载new.html.haml视图时，我收到此错误：

Unknown attribute: question_id

视图如下所示：

= simple_form_for @question do |f|
  = f.input :title
  = f.simple_fields_for :answers do |a|
    = a.input :text
  = f.submit

Answer 1

似乎您忘记在Answers表中创建question_id字段。

两个模型Question and Answer之间存在1-M关系。确保Answers表中有foreign_key question_id。