产品和类别关系

Question

试图在我的应用程序中具有以下关系。

产品可以属于许多类别，子类别和子类别。

目前的设计：

Product: 
    has_many :categorizations, dependent: :destroy 
    has_many :categories, through: :categorizations 
    has_many :sub_categories, through: :categorizations 
    has_many :sub_sub_categories, through: :categorizations 

Category: 
    has_many :categorizations 
    has_many :products, through: :categorizations 
    has_many :sub_categories, class_name: 'Category', foreign_key: 'parent_id' 
    belongs_to :parent_category, class_name: 'Category', foreign_key: 'parent_id' 

Categorization: 
    belongs_to :category 
    belongs_to :sub_category, class_name: 'Category', foreign_key: 'sub_category_id' 
    belongs_to :sub_sub_category, class_name: 'Category', foreign_key: 'sub_sub_category_id' 
    belongs_to :product 

产品特定类别的可以被列为category.products。

如何访问特定产品sub_category和sub_sub_category？

我应该做些什么？

Answer 1

将此线路has_many :sub_sub_categories, through: :sub_categories添加到Product型号。

## app/models/product.rb 
has_many :sub_categories 
has_many :categories, through: :sub_categories 
has_many :sub_sub_categories, through: :sub_categories 

如果我是你，我会设计这样的：

Product: 
    has_many :categorizations 
    has_many :categories, through: :categorizations 

Categorization: 
    belongs_to :product 
    belongs_to :category 

Category: 
    belongs_to :parent, class_name: 'Category', optional: true 
    has_many :children, class_name: 'Category', foreign_key: :parent_id, dependent: :nullify 

    has_many :categorizations 
    has_many :products, through: :categorizations 

注：添加parent_id表categories