Ruby on rails 如何在ActiveRecord中为多态模型按父级属性排序？

我想我的措辞是正确的

我有一个叫做资产的模型，它是多态的：

class Asset < ActiveRecord::Base
  belongs_to :assetable, :polymorphic => true
...
end

我正在尝试获取一个资产列表，该资产的父级的approved_at属性不为空，并按approved_at属性降序排列，限制为50。我承认，我不确定我所做的有多接近于正确，但我现在得到的错误是：

"Can not eagerly load the polymorphic association :assetable"

---

正确的方法是以不同的方式思考：

# If assetable model is called Folder
def self.some_scope
   folders = Folder.where('approved_at IS NOT NULL').order('approved_at DESC').limit(50)
   folders.collect{|p| p.assets}
end

# If assetable model is called Folder
def self.some_scope
   folders = Folder.where('approved_at IS NOT NULL').order('approved_at DESC').limit(50)
   folders.collect{|p| p.assets}
end