的has_many：通過調查屬性

Question

我有一個可以代表參加的調查顯示：

調查的has_many：問題其中的has_many：答案

參與者應該能夠給他投票添加到每個回答的（值是[1,0,1]）

一個問題是這樣的：

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) 

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

添加了解釋：

（用戶會得到答案）

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

我覺得你participant和user模型需要被合併成一個，因爲不是participant的user？我不明白爲什麼Participant模型在這裏是必要的。

說，我們合併User和Participant逼到User，User和Voting之間的關聯將被：

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 

從你的第一個代碼塊

現在：

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) 

是不是投票用戶的答案完成？那麼我們是否需要user has_many :votings關係？我認爲協會口語會是User需要很多Surveys,Survey有很多Questions,Question有很多Answers和答案有很多Votings。每個投票都可以被檢查。所以對於這個我不認爲User和Voting之間的直接聯繫是解決方案。

以下是更新User，Answer和Voting機型更新的關聯：

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 

最後有一對夫婦的其他小錯別字像Answers < ActiveRecord::Base其中類Answer不應該是複數。

第二個問題是你有Userhas_and_belongs_to_manySurveys。要定義many to many關係Survey之間User，所以你需要定義同在Survey型號還有：

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

與所有這些更新與關係沿着您的模型將如下所示（注：我也在模型中加入accepts_nested_attributes_for所以，當你的表單提交你不需要手工打造每一個相關聯的對象）：

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relationshp你可以建立你的SurveysController的new和create行動將類似於如下：

# 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 

此外，我建議你看看has_many...through而不是has_and_belongs_to_many定義many to many關係。