通过关联嵌套的 has_many 不起作用

Question

运行 Rails 3.2.1。如文档 (http://guides.rubyonrails.org/association_basics.html#the-has_many-through-association) 所示，通过关联尝试应该是简单的嵌套 has_many：

class Company < ActiveRecord::Base
  has_many :locations, :dependent => :destroy
  has_many :assets,  :through => :locations
  has_many :components,  :through => :assets
end

class Location < ActiveRecord::Base
  belongs_to :company
  has_many :assets
  has_many :components, :through => :assets
end

class Asset < ActiveRecord::Base
  belongs_to :location
  has_many :components
end

class Component < ActiveRecord::Base
  belongs_to :asset
end

在控制台中Company.find(2) 和Company.find(2).locations 一样工作正常，但不是Company.find(2).assets 或Company.find(2).components。我明白了：

1.9.3p0 :071 > Company.find(2).assets
  Company Load (0.8ms)  SELECT "companies".* FROM "companies" WHERE "companies"."id" = $1 ORDER BY name ASC LIMIT 1  [["id", 2]]
NoMethodError: undefined method `assets' for #<Company:0x007f939d714318>

我似乎在这里遗漏了一些东西。我嵌套了一层更深，但根据文档，这应该没问题。

Answer 1

哇……快把我逼疯了。希望我能帮助别人。搜索了控制台错误消息，只需要重新加载控制台... D'oh！