Ruby on rails Rails:Query for具有许多直通关联

我有以下联想

class Post < ActiveRecord::Base
  has_many :categorizations
  has_many :categories, through: :categorizations

class Categorization < ActiveRecord::Base
  belongs_to :category
  belongs_to :post
end

class Category < ActiveRecord::Base
  has_many :categorizations
  has_many :posts, through: :categorizations
end

我需要与@posts关联的所有类别。所以我需要这样的东西

@categories = @posts.categories

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因此，如何获取相关的帖子类别。

您可以使用includes加载每个帖子的类别

current_user.posts.includes(:categories)

current_user.posts.includes(:categories)