Rails mutlipe has_many通过不同的模型到单个模型

Question

我是Rails的新手，在构架Rails模型时需要一些帮助。 我有四个模型User，Product，UserSavedProduct，likedProduct。

用户可以通过用户购买的产品和喜欢的产品获得很多产品，这些是我的模型。 这是编写它们的正确方法吗？ 如果是这样，如何获取所有保存的产品，喜欢单个用户的产品，还可以为我指出正确的方向。

class User < ActiveRecord::Base

  has_many :user_saved_products

  has_many :saved_products,:through => :user_saved_products,:source => :products

  has_many :product_likes

  has_many :products,:through => :product_likes

End


class UserSavedProduct < ActiveRecord::Base

  belongs_to :user

  belongs_to :product

end

class ProductLike < ActiveRecord::Base

  belongs_to :user

  belongs_to :product

end


class Product < ActiveRecord::Base

  belongs_to :user

  has_many :user_saved_products

  has_many :users, :through => :user_saved_products

  has_many :product_likes

  has_many :users,:through => :product_likes

end

当我做User.first.methods.grep（/ product /）

=> [：autosave_associated_records_for_user_saved_products，：validate_associated_records_for_user_saved_products，：before_add_for_user_saved_products，：before_add_for_user_saved_products ?,：before_add_for_user_saved_products =，：after_add_for_user_saved_products，：after_add_for_user_saved_products ?,：after_add_for_user_saved_products =，：before_remove_for_user_saved_products，：before_remove_for_user_saved_products ?,：before_remove_for_user_saved_products =，：after_remove_for_user_saved_products，：after_remove_for_user_saved_products ?,： after_remove_for_user_saved_products =，：autosave_associated_records_for_saved_products，：validate_associated_records_for_saved_products，：before_add_for_saved_products，：before_add_for_saved_products ?,：before_add_for_saved_products =，：after_add_for_saved_products，：after_add_for_saved_products ?,：after_add_for_saved_products =，：before_remove_for_saved_products，：before_remove_for_saved_products ?,：before_remove_for_saved_products =，：after_remove_for_saved_pr oducts，：after_remove_for_saved_products ?,：after_remove_for_saved_products =，：autosave_associated_records_for_product_likes，：validate_associated_records_for_product_likes，：before_add_for_product_likes，：before_add_for_product_likes ?,：before_add_for_product_likes =，：after_add_for_product_likes，：after_add_for_product_likes ?,：after_add_for_product_likes =，：before_remove_for_product_likes，：before_remove_for_product_likes ?,：before_remove_for_product_likes =，： after_remove_for_product_likes，：after_remove_for_product_likes ?,：after_remove_for_product_likes =，：autosave_associated_records_for_liked_products，：validate_associated_records_for_liked_products，：before_add_for_liked_products，：before_add_for_liked_products ?,：before_add_for_liked_products =，：after_add_for_liked_products，：after_add_for_liked_products ?,：after_add_for_liked_products =，：before_remove_for_liked_products，：before_remove_for_liked_products ?,：before_remove_for_liked_products =，： after_remove_for_liked_products，：a fter_remove_for_liked_products ?,：after_remove_for_liked_products =，：user_saved_products，：user_saved_product_ids，：user_saved_products =，：user_saved_product_ids =，：saved_products，s_save_id，slike： Liked_products，：liked_product_ids，：liked_products = 、: liked_product_ids =]

Answer 1

您遇到的主要问题是您的产品模型-您有多个:users关联。 我会这样设置。

我必须从产品返回用户中选择两个关联名称。 我选择了liking_users和saving_users ，如果您不喜欢它们，可以重命名。

如果执行此操作，则将ProductLike类重命名为“ UserLikedProduct”，以使其与“ UserSavedProduct”保持一致。 显然，如果您这样做，则需要更改数据库表名称和引用该表​​的关联。

class User < ActiveRecord::Base
  has_many :user_saved_products
  has_many :saved_products, :through => :user_saved_products, :class_name => "Product"
  has_many :product_likes
  has_many :liked_products,:through => :product_likes, :class_name => "Product"
end

class Product < ActiveRecord::Base
  has_many :user_saved_products
  has_many :saving_users, :through => :user_saved_products, :class_name => "User"
  has_many :product_likes
  has_many :liking_users, :through => :product_likes, :class_name => "User"
end    

class UserSavedProduct < ActiveRecord::Base
  belongs_to :user
  belongs_to :product
end

class ProductLike < ActiveRecord::Base
  belongs_to :user
  belongs_to :product
end