未初始化的恒定红宝石模型

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.分类

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，当我在视图中打电话时

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

我收到此错误：

uninitialized constant Article::CategoriesArticle 

Subcategory和subcategory_article类也是如此

Answer 1

尝试

has_many :category_articles

和

has_many :subcategory_articles

您还必须更改以下内容：

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

像这样：

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

Rails不会将复合表名称的两个组成部分都进行复数处理。 只是最后一个组件。