Question

我有一个有三种型号的rails应用程序：帐户，包裹和交付。我在交货时使用AR :: Relation范围来查找最近的交货和退货。帐户模型还需要查找最近交付的帐户。 我可以通过joins在帐户中使用相同的投放范围吗？现在我正在使用这样的代码（请注意Account.with_recent_returns和Delivery.recent_returns中的重复项）：

# Package(id: integer, ident: string)

class Package < ActiveRecord::Base
  has_many :deliveries, :dependent => :destroy
end

# Delivery(id: integer, account_id: integer, delivered_on: date, package_id: integer, returned_on: date)`

class Delivery < ActiveRecord::Base

  belongs_to :account
  belongs_to :package

  scope :current, where(:returned_on => nil)

  scope :recent_deliveries, where('delivered_on >= ?', 2.weeks.ago)

  scope :recent_returns, where('returned_on >= ?', 2.weeks.ago)

  scope :returns, where('returned_on IS NOT NULL')
end

#  => Account(id: integer, name: string)

class Account < ActiveRecord::Base

  has_many :deliveries, :dependent => :destroy

  def self.with_current_deliveries
    joins(:deliveries).where(:deliveries => { :returned_on => nil } ).includes(:deliveries)
  end


  def self.with_recent_returns
    joins(:deliveries).where('deliveries.returned_on >= ?', 2.weeks.ago).includes(:deliveries)
  end
end

Answer 1

我相信这样的事情会起作用

scope :recent_deliveries, joins(:deliveries).merge(Delivery.recent)

或者你可能需要使用范围

scope :recent_deliveries, scoped.joins(:deliveries).merge(Delivery.recent)

应该让你入门。

跨模型使用ActiveRecord :: Relations

1 个答案: