Question

我有参与者可以参加的调查：

调查has_many：has_many：答案

的问题

参与者应该能够将他的投票添加到每个答案中（值为[-1,0,1]）

一个问题如下：

Question 1
 - Answer1 -> Please vote -1 / 0 / 1 (Checkbox field)
 - Answer2 -> Please vote -1 / 0 / 1 (Checkbox field)
 - Answer3 -> Please vote -1 / 0 / 1 (Checkbox field)
 - Participant Comment               (Text Field)
 - Participant Average               (Rating Field)

如何正确保存投票？我想保持participant_id, answer_id AND voting_value得到保存。

增加了解释：

（用户将得到答案）

User < ActiveRecord::Base
  has_and_belongs_to_many :surveys
  has_many :participants
end

Survey < ActiveRecord::Base
  belongs_to :user
  has_many :questions
end

Question < ActiveRecord::Base
  belongs_to :survey
  has_many :answers
end

Answers < ActiveRecord::Base
  belongs_to :question
  has_many :votings
end

Voting < ActiveRecord::Base
  belongs_to :answer
  belongs_to :participant
  attr_accessible :value
end

Participant < ActiveRecord::Base
  has_many :votings
  belongs_to :user
end

Answer 1

我认为您的participant和user模型需要合并为一个，因为不是participant和user？我不明白为什么Participant模型在这里是必要的。

说，我们将User和Participant合并到User，User和Voting之间的关联将是：

User < ActiveRecord::Base
  has_and_belongs_to_many :surveys
  has_many :votings 
end

Voting < ActiveRecord::Base
  belongs_to :answer
  belongs_to :user
  attr_accessible :value
end

现在从你的第一个代码块开始：

Question 1
 - Answer1 -> Please vote -1 / 0 / 1 (Checkbox field)
 - Answer2 -> Please vote -1 / 0 / 1 (Checkbox field)
 - Answer3 -> Please vote -1 / 0 / 1 (Checkbox field)
 - Participant Comment               (Text Field)
 - Participant Average               (Rating Field)

用户的答案是否未完成投票？在那种情况下，我们需要user has_many :votings关系吗？我认为发出的关联是User需要很多Surveys，Survey有很多Questions，Question有很多Answers而答案有很多Votings。可以检查每个投票。因此，我不认为User和Voting之间的直接关联是解决方案。

以下内容已更新User，Answer和Voting型号，并附有更新关联：

User < ActiveRecord::Base
  has_and_belongs_to_many :surveys
end

Answer < ActiveRecord::Base
  belongs_to :question
  has_many :votings
end

Voting < ActiveRecord::Base
  belongs_to :answer
  attr_accessible :value
end

最后还有一些其他小错别字错误，例如Answers < ActiveRecord::Base，其中班级Answer不应该是复数。

第二个问题是你有User has_and_belongs_to_many Surveys。您正在定义many to many和User之间的Survey关系，因此您需要在Survey模型中定义相同的内容：

Survey < ActiveRecord::Base
  has_and_belongs_to_many :users
  has_many :questions
end

通过所有这些更新，您的模型以及关系将如下所示（注意：我还在模型中添加了accepts_nested_attributes_for，以便在您提交表单时无需手动构建每个关联对象）：

User < ActiveRecord::Base
  has_and_belongs_to_many :surveys
end

Survey < ActiveRecord::Base
  has_and_belongs_to_many :users
  has_many :questions

  accepts_nested_attributes_for :questions
end

Question < ActiveRecord::Base
  belongs_to :survey
  has_many :answers

  accepts_nested_attributes_for :answers
end

Answers < ActiveRecord::Base
  belongs_to :question
  has_many :votings

  accepts_nested_attributes_for :votings
end

Voting < ActiveRecord::Base
  belongs_to :answer
  attr_accessible :value     
end

使用上述模型关系，您可以构建SurveysController的{{1}}和new操作看起来类似于以下内容：

create

另外，我建议您调查# app/controllers/surveys_controller.rb class SurveysController < ApplicationController def new @survey = current_user.surveys.build do @question = @survey.questions.build @answer = @question.answers.build # Build three different votings for answer with default value. [-1, 0, 1].each do |voting_value| @answer.votings.build(value: voting_value) end end def create @survey = current_user.surveys.build(params[:survey]) @survey.save # Of course you would check if save succeeded or failed and take action accordingly. end end而不是has_many...through来定义has_and_belongs_to_many关系。

has_many：通过Survey属性

1 个答案: