Rails 3 ActiveRecord关联的集合自定义方法

对不起,我想出来了。我曾尝试将该方法添加到ActiveRecord Bid类中,但我忘记将其设置为类方法,所以它看不到该方法。

class Bid < ActiveRecord::Base
  ...
  def self.highest
    last(:order => :amount)
  end

但这并不是百分之百地处理关联。现在就写些测试。

编辑:

一个快速测试似乎表明,这似乎也神奇地处理了关联。

test "highest bid finder associates with auction" do
  auction1 = install_fixture :auction, :reserve => 10
  auction2 = install_fixture :auction, :reserve => 10

  install_fixture :bid, :auction => auction1, :amount => 20, :status => Bid::ACCEPTED
  install_fixture :bid, :auction => auction1, :amount => 30, :status => Bid::ACCEPTED
  install_fixture :bid, :auction => auction2, :amount => 50, :status => Bid::ACCEPTED

  assert_equal 30, auction1.bids.highest.amount, "Highest bid should be $30"
end

如果关联不正确,测试将找到50美元的出价。伏都教;)

highest_bid 你的方法 Auction

class Auction < ActiveRecord::Base
  has_many :bids

  def highest_bid
    bids.last(:all, :order => :amount)
  end
end

highest_bid = auction.highest_bid