多态、has_one和作用域关联的检索方法

Question

嗨，这有点微不足道，但我无论如何也想不出该在哪里做调整。我有一个LoanApplication模型和一个如下的传输模型：

class LoanApplication < ActiveRecord::Base
  before_save :populate_guid
  belongs_to :user
  has_one :loan, -> { where loan: true }, as: :transferable
  has_one :repayment, -> { where repayment: true }, as: :transferable
  validates_uniqueness_of :guid  

  private 

  def populate_guid
    if new_record?
      while !valid? || self.guid.nil?
        self.guid = SecureRandom.random_number(1_000_000_000).to_s(36)
      end
    end
  end
end

和

class Transfer < ActiveRecord::Base
  belongs_to :transferable, polymorphic: true 
  belongs_to :user
 validates_presence_of :transferable_id,
                    :transferable_type,
                    :user_id,
                    :amount,
                    :password
end

为什么LoanApplication.first.loan会给我以下错误信息

LoanApplication Load (1.1ms)  SELECT  "loan_applications".* FROM "loan_applications"  ORDER BY "loan_applications"."id" ASC LIMIT 1
NameError: uninitialized constant LoanApplication::Loan

感谢大家的真知灼见。谢谢

Answer 1

我认为Application是一个保留字。尝试重命名LoanApplication？

Answer 2

这是微不足道的，我只需要添加class_name: "Transfer"就可以让一切正常工作。-__-‘