RailsAdmin中具有join_table和has_many的模型的路由错误

Question

所以，我有3种型号：category，product，category_products。

这是我的 category.rb

  attr_accessible :name
    has_many :category_products do
         def with_products
           includes(:product)
         end
       end

  has_many :products, :through => :category_products

这是我的 product.rb

  attr_accessible :name, :description, :price, :vendor_id, :image, :category_ids

    belongs_to :vendor
    has_many :category_products do
           def with_categories
             includes(:category)
           end
    end

    has_many :categories, :through => :category_products

这是我的 category_product.rb

  attr_accessible :product_id, :category_id, :purchases_count

    belongs_to :product
  belongs_to :category

  validates_uniqueness_of :product_id, :scope => :category_id

这是我的 routes.rb

  mount RailsAdmin::Engine => '/admin', :as => 'rails_admin'
  resources :categories
  resources :vendors do
      resources :products
  end

  authenticated :user do
    root :to => 'home#index'
  end

  root :to => "home#index"
  devise_for :users
  resources :users

当我在Categories查看RailsAdmin时单击时，出现此错误：

ActionController::RoutingError at /admin/category

Message No route matches {:action=>"show", :model_name=>"category_product", :id=>nil, :controller=>"rails_admin/main"}

当我单击时，我也会收到此错误 Category Products

ActiveRecord::StatementInvalid at /admin/category_product

Message SQLite3::SQLException: no such column: category_products.desc: SELECT "category_products".* FROM "category_products" ORDER BY category_products. desc LIMIT 20 OFFSET 0

我的其他“正常”（即非HMT）模型在RailsAdmin中的所有其他链接都可以使用。

是什么原因造成的？

谢谢。

编辑1

对于它的价值，这是当我单击Rails Admin内部的“类别”时的日志：

CodeRay::Scanners could not load plugin nil; falling back to :text
CodeRay::Scanners could not load plugin nil; falling back to :text


Started GET "/admin/category?_pjax=%5Bdata-pjax-container%5D" for 127.0.0.1 at 2012-12-20 22:23:38 -0500
Processing by RailsAdmin::MainController#index as HTML
  Parameters: {"_pjax"=>"[data-pjax-container]", "model_name"=>"category"}
  Category Load (0.3ms)  SELECT "categories".* FROM "categories" LIMIT 6
  User Load (0.2ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" ORDER BY categories.id desc LIMIT 20 OFFSET 0
  CategoryProduct Load (0.2ms)  SELECT "category_products".* FROM "category_products" WHERE "category_products"."category_id" = 2
  Rendered /.rvm/gems/ruby-1.9.3-p194@apt-605/gems/rails_admin-0.3.0/app/views/rails_admin/main/index.html.haml within layouts/rails_admin/pjax (29.4ms)
Completed 500 Internal Server Error in 43ms
CodeRay::Scanners could not load plugin nil; falling back to :text
CodeRay::Scanners could not load plugin nil; falling back to :text


Started GET "/admin/category" for 127.0.0.1 at 2012-12-20 22:23:40 -0500
Processing by RailsAdmin::MainController#index as HTML
  Parameters: {"model_name"=>"category"}
  Category Load (0.3ms)  SELECT "categories".* FROM "categories" LIMIT 6
  User Load (0.2ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
  Category Load (0.2ms)  SELECT "categories".* FROM "categories" ORDER BY categories.id desc LIMIT 20 OFFSET 0
  CategoryProduct Load (0.2ms)  SELECT "category_products".* FROM "category_products" WHERE "category_products"."category_id" = 2
  Rendered /.rvm/gems/ruby-1.9.3-p194@apt-605/gems/rails_admin-0.3.0/app/views/rails_admin/main/index.html.haml within layouts/rails_admin/application (30.5ms)
Completed 500 Internal Server Error in 251ms

编辑2

这是错误的全部踪迹的要点。我正在使用gem Better_errors宝石，因此跟踪看起来不像标准的Rails跟踪错误。但是数据是一样的。

编辑3

这是我的3个模型的架构：

CategoryProducts

# == Schema Information
#
# Table name: category_products
#
#  product_id      :integer
#  category_id     :integer
#  purchases_count :integer          default(0)
#  created_at      :datetime         not null
#  updated_at      :datetime         not null

Category

# == Schema Information
#
# Table name: categories
#
#  id         :integer          not null, primary key
#  name       :string(255)
#  created_at :datetime         not null
#  updated_at :datetime         not null

Product

# == Schema Information
#
# Table name: products
#
#  id          :integer          not null, primary key
#  name        :string(255)
#  description :string(255)
#  price       :float
#  vendor_id   :integer
#  created_at  :datetime         not null
#  updated_at  :datetime         not null
#  image       :string(255)

请注意，CategoryProduct它没有主键字段。那是问题吗？

Answer 1

检查所有 CategoryProduct 对象都有外键：category_id 和 Product_id。

CategoryProduct.all.each {|c| raise("Repair #{c.id}") unless c.category && c.product}

12月21日更新：

我如何安装全新的 Rails 3.2.9 以及类别、产品和类别产品。模型的关系代码是相同的，RailsAdmin 使用默认设置。

而且它的工作没有任何问题！

我决定检验我的假设。我想也许当您从 HABTM 转到 HM2HM 时，您错过了（忘记）为 CategoryProduct 重新建立关键列 ID，它现在不仅仅是一个连接模型，而是一个独立的实体。

因此，路由错误如下：

No route matches {:action=>"show", :model_name=>"category_product", :id=>nil, :controller=>"rails_admin/main"}

可能是缺少 id的结果。

好吧，我手动禁用了 CategoryProduct 的 id 字段（def id; nil; end）。

是的，它是：

No route matches {:action=>"show", :model_name=>"category_product", :id=>nil, :controller=>"rails_admin/main"}