Ruby on rails 轨道3.2类和；子类别

实际上，我正在开发一个应用程序，它需要将一个练习链接到许多子类别，这些子类别是父类别的子类别

这是我的代码：

练习.rb属于：子类别

class Exercice < ActiveRecord::Base
attr_accessible :title, :description, :subcategory_id

validates :title, :presence => true

has_many :programmeexercices
has_many :programmes, :through => :programmeexercices
belongs_to  :subcategory

end

类别控制器

def new
    @exercice = Exercice.new
    @subcategories = Subcategory.all 
  end

  def edit
    @exercice = Exercice.find(params[:id])
    @subcategories = Subcategory.all
  end

  def create
    @exercice = Exercice.new(params[:exercice])
    params[:subcategories][:id].each do |subcategory|
      if !subcategory.empty?
        @exercice.subcategory.build(:subcategory_id => subcategory)
      end
  end

 def new
    @category = Category.new
  end

  def edit
    @category = Category.find(params[:id])
  end

 def create
    @category = Category.new(params[:category])
  end

def new
    @subcategory = Subcategory.new
    @categories = Category.all
  end

def edit
    @subcategory = Subcategory.find(params[:id])
    @categories = Category.all
  end

  def create
    @subcategory = Subcategory.new(params[:subcategory])

    params[:categories][:id].each do |category|
      if !category.empty?
        @subcategory.category.build(:category_id => category)
      end
  end

子类别\u控制器

def new
    @exercice = Exercice.new
    @subcategories = Subcategory.all 
  end

  def edit
    @exercice = Exercice.find(params[:id])
    @subcategories = Subcategory.all
  end

  def create
    @exercice = Exercice.new(params[:exercice])
    params[:subcategories][:id].each do |subcategory|
      if !subcategory.empty?
        @exercice.subcategory.build(:subcategory_id => subcategory)
      end
  end

 def new
    @category = Category.new
  end

  def edit
    @category = Category.find(params[:id])
  end

 def create
    @category = Category.new(params[:category])
  end

def new
    @subcategory = Subcategory.new
    @categories = Category.all
  end

def edit
    @subcategory = Subcategory.find(params[:id])
    @categories = Category.all
  end

  def create
    @subcategory = Subcategory.new(params[:subcategory])

    params[:categories][:id].each do |category|
      if !category.empty?
        @subcategory.category.build(:category_id => category)
      end
  end

练习表单视图我想：为练习分配子类别

      <li id="p-select">
        <% for subcategory in Subcategory.find(:all) %>
        <div class="row">
          <section class="twelve columns">
            <article class="valign row">
              <div>
                <label class="checkbox">
                   <%= check_box_tag "checkboxInput", subcategory.id, @exercice.subcategories.include?(subcategory) %>                                    
                </label> 
              </div>
               <div>
                <h3><%= exercice.title %></h3>
              </div>                       
          </article>
          <% end %>
          </section>
        </div>
      </li>
    </li>

子类别\u表单视图我想：为子类别分配一个类别

class Category < ActiveRecord::Base
attr_accessible :name

has_many :exercices, :through => :subcategories
has_many :subcategories
end

<li class="field">
      <%= f.label :category %><br />
      <%= f.collection_select(:category_id, @categories, :id, :name, :include_blank => "Please select") %>
  </li>

“请选择”）%%>

不管是哪种形式，我都会收到一条错误消息：

=>子类别/新：

NoMethodError in Subcategories#new
undefined method `category_id' for #<Subcategory:0x4f676b8>

app/views/subcategories/_form.html.erb:16:in `block in _app_views_subcategories__form_html_erb___180268787_42055560'
app/views/subcategories/_form.html.erb:1:in `_app_views_subcategories__form_html_erb___180268787_42055560'
app/views/subcategories/new.html.erb:3:in `_app_views_subcategories_new_html_erb___1058729489_29352300'
app/controllers/subcategories_controller.rb:30:in `new'

子类别中的命名错误#新增 未定义的方法“category_id”# app/views/subcategories/_form.html.erb:16:in`block in_app_views_subcategories_form_html_erb_180268787_42055560' app/views/subcategories/_form.html.erb:1:in`_app_views_subcategories_form_html_erb___180268787_42055560' app/views/subcategories/new.html.erb:3:in`_app_views_subcategories_new_html_erb_1058729489_29352300' app/controllers/subcategories_controller.rb:30:in'new' =>练习/新：

NoMethodError in Exercices#new
undefined method `subcategories' for #<Exercice:0x4c992c0>

  app/views/exercices/_form.html.erb:31:in `block (2 levels) in _app_views_exercices__form_html_erb__725096104_41604048'
app/views/exercices/_form.html.erb:25:in `each'
 app/views/exercices/_form.html.erb:25:in `block in _app_views_exercices__form_html_erb__725096104_41604048'
 app/views/exercices/_form.html.erb:2:in `_app_views_exercices__form_html_erb__725096104_41604048'
 app/views/exercices/new.html.erb:3:in `_app_views_exercices_new_html_erb___924742088_42063192'
 app/controllers/exercices_controller.rb:31:in `new'

exercies中的命名错误#新增
未定义的方法“子类别”#
app/views/exercies/_form.html.erb:31:in`block（2层）in_app_views\u exercies\u form\u html\u erb\u 725096104\u 41604048'
app/views/exercies/_form.html.erb:25:in'each'
app/views/exercies/_form.html.erb:25:in`block in_app_views_exercies_form_html_erb_725096104_41604048'
app/views/exercices/_form.html.erb:2:in``应用程序视图_exercices _表单_html _erb _725096104 _41604048'
app/views/exercices/new.html.erb:3:in`_app\u views\u exercices\u new\u html\u erb\u 924742088\u 42063192'
app/controllers/exercices\u controller.rb:31:in'new'

---

有人知道我错在哪里吗？谢谢：）

老实说，我认为您需要回去重新编写大量代码

您在表单中调用了

exercies.subcategories

，这导致了第二个错误，因为

练习
属于：subcategory
，因此每个练习只能有一个子类别

您正在遍历所有子类别，以便在练习表单上为每个子类别提供一个复选框，这表明您实际上希望一个练习包含许多子类别

您已将复选框命名为tax
checkBoxInput
，然后您希望控制器中有一个参数
subcategories[]

您还将输出每个子类别的练习标题

因此，在尝试修复特定错误之前，我会后退几步，整理大量代码逻辑。
好的，我明白了

我想要的是：
一个练习有多个子类别，只有一个类别。
子类别只有一个类别。
一个类别有多个子类别

****class Exercice < ActiveRecord::Base****
  attr_accessible :title, :subcategory_id

  has_many :subcategories
  has_one :category, :through => :subcategories


****class Category < ActiveRecord::Base*****
  attr_accessible :name

  has_many :subcategories
  has_many :exercices, :through => :subcategories


***class Subcategory < ActiveRecord::Base****
  attr_accessible :name, :category_id

  belongs_to :category
  has_many :exercices

****类练习：子类别
****类类别：子类别
***类子类别

是吗？
也许值得花更多的精力来提供有关错误的一些细节。例如，他们的stacktrace是什么？此外，您的表单代码似乎有点混乱，例如：
用于子类别中的练习。查找（：all）
是练习还是子类别？没错，我编辑了错误消息，还修改了复选框标记的内容。我看不出这些错误是从哪里来的，你能帮忙吗？离题了，但一年后当你意识到“锻炼”的拼写错误时，它真的会让你恼火——我现在要修改它。但它是法语！！！：）编辑：我在muh文本中修改了错误的英语单词，对此我很抱歉：）