Rails5表单:遍历集合以获取问题列表，但更新不同的模型

# app/models/question.rb
class Question < ApplicationRecord
  has_many :answers, dependent: :destroy
  accepts_nested_attributes_for :answers, reject_if: :all_blank, allow_destroy: true
end

# app/models/answer.rb
class Answer < ApplicationRecord
  belongs_to :question
end

# app/controllers/questions_controller.rb
class QuestionsController < ApplicationController
  def new
    @question = Question.new
    3.times { @question.answers.build }
  end

  def create
    @question = Question.new(question_params)
    if @question.save
      redirect_to @question
    else
      render :new
    end
  end

  private

  def question_params
    params.require(:question).permit(:title, answers_attributes: [:id, :content, :_destroy])
  end
end

<!-- app/views/questions/new.html.erb -->
<%= form_with(model: @question, local: true) do |form| %>
  <%= form.label :title %>
  <%= form.text_field :title %>

  <%= form.fields_for :answers do |answer_fields| %>
    <%= answer_fields.label :content %>
    <%= answer_fields.text_field :content %>
    <%= answer_fields.check_box :_destroy %>
    <%= answer_fields.label :_destroy, 'Remove' %>
  <% end %>

  <%= form.submit %>
<% end %>

# app/controllers/questions_controller.rb
class QuestionsController < ApplicationController
  # ...

  def update
    @question = Question.find(params[:id])
    if @question.update(question_params)
      redirect_to @question
    else
      render :edit
    end
  end

  # ...
end