未初始化的常量红宝石模型

Question

我有 3 节课：
1.文章

class Article < ActiveRecord::Base
  has_many :categories_articles
  has_many :subcategories_articles
  has_many :categories, :through => :categories_articles
  has_many :subcategories, :through => :subcategories_articles
end

2.类别

class Category < ActiveRecord::Base  
  has_many :articles  
  has_many :categories_articles  
  has_many :categories_subcategories  
  has_many :subcategories, :through => :categories_subcategories  
  has_many :articles, :through => :categories_articles  
end

3.第三个类是前两个的并集，category_article

class CategoryArticle < ActiveRecord::Base  
  belongs_to :category  
  belongs_to :article  
end

所以，当我在视图中调用时

<% f.collection_select(:category_ids, Category.all, :id, :name, {include_blank:"selects"},{class:'form-control select2 multi', :required=>true, multiple: true}) %>

我得到这个错误：

uninitialized constant Article::CategoriesArticle 

Subcategory 和 subcategory_article 类也是如此

Answer 1

试试

has_many :category_articles

和

has_many :subcategory_articles

您还必须更改这些：

has_many :categories, :through => :categories_articles
has_many :subcategories, :through => :subcategories_articles

类似于：

has_many :categories, :through => :category_articles
has_many :subcategories, :through => :subcategory_articles

Rails 不会复数组合表名的两个组成部分。只是最后一个组件。