ruby-on-rails - Rails - ActiveRecord 包含多个级别

Question

参见下面的关联:

class Continent < ActiveRecord::Base
    has_many :countrys

class Country < ActiveRecord::Base
    belongs_to :continent
    has_many :addresses

class Address < ActiveRecord::Base
    belongs_to :person
    belongs_to :street

class Person < ActiveRecord::Base
    has_many :addresses

我如何从 Person.includes() 开始，并在查询数据库时一直包含关联到大陆。

我已经能够通过 .includes(addresses: :country) 包含国家/地区，但似乎没有达到最后一级。

Answer 1

您可以再添加 1 级哈希:

.includes(addresses: {country: :continent})