ruby-on-rails-3 - Rails 3 : Multiple has_one associations & seeding

我正在研究一个 Rails 似乎不太擅长的数据概念——一条路线有两个(而且只有两个)机场。我终于想出了如何对我的外键进行硬编码，以便它们变得合理。

我的 models/route.rb 非常简单:

class Route < ActiveRecord::Base
  has_one :airport, :foreign_key => 'from_airport_id', :class_name => 'Airport'
  has_one :airport, :foreign_key => 'to_airport_id', :class_name => 'Airport'
end

这一切似乎都运行良好，但我似乎无法正确播种。

我的 seeds.rb 看起来像这样:

Airport.delete_all
@kpdx = Airport.create(:icao => 'KPDX', :name => 'Portland International Airport', :lat => '45.58869934', :lon => '-122.5979996')
@ksea = Airport.create(:icao => 'KSEA', :name => 'Seattle Tacoma International Airport', :lat => '47.4490013122559', :lon => '-122.30899810791')
Route.delete_all
Route.create(:from_airport_id => @kpdx, :to_airport_id => @ksea, :route => "RIVR6 BTG OLM6")
Route.create(:from_airport_id => @kpdx, :to_airport_id => @ksea, :route => "BTG OLM OLM6")

Route.create(:from_airport_id => Airport.find_by_icao("KSEA"), :to_airport_id => Airport.find_by_icao("KPDX"), :route => "SEATL4 SEA HELNS4")
Route.create(:from_airport_id => Airport.find_by_icao("KSEA"), :to_airport_id => Airport.find_by_icao("KPDX"), :route => "SEA HELNS4")

请注意，我有两种不同的方法试图告诉种子数据从我创建的一个机场到另一个机场。一个都不行。当我运行 rake db:seed 时，所有 from_airport_id 和 to_airport_id 字段都设置为 1，此时 airport 表中的 ID 正在递增(在我当前的运行中为 23 和 24)。

所以我有两个问题:

有没有比我正在做的更好的方法来处理模型代码？

我在播种时做错了什么:-)

谢谢!

最佳答案

我会改变你的模型来为每个关系指定一个不同的符号:

class Route < ActiveRecord::Base
  has_one :from_airport, :foreign_key => 'from_airport_id', :class_name => 'Airport'
  has_one :to_airport, :foreign_key => 'to_airport_id', :class_name => 'Airport'
end

由于启用 has_one 可以让您通过名称(例如 route.airport )访问该关系，因此这些需要不同。

要使您的播种工作，请在机场致电 .id:

Route.create(:from_airport_id => @kpdx.id, :to_airport_id => @ksea.id, :route => "RIVR6 BTG OLM6")

例子:

ruby-1.9.2-p136 :001 > a = Airport.create(:icao => 'KPDX', :name => 'Portland International Airport')
 => #<Airport id: 1, icao: "KPDX", name: "Portland International Airport", created_at: "2011-03-01 02:44:42", updated_at: "2011-03-01 02:44:42">
ruby-1.9.2-p136 :002 > b = Airport.create(:icao => 'ABCD', :name => 'Another Airport')
 => #<Airport id: 2, icao: "ABCD", name: "Another Airport", created_at: "2011-03-01 02:46:22", updated_at: "2011-03-01 02:46:22">
ruby-1.9.2-p136 :003 > r = Route.create(:to_airport_id => a.id, :from_airport_id => b.id)
 => #<Route id: 3, from_airport_id: 2, to_airport_id: 1, route: nil, created_at: "2011-03-01 02:46:36", updated_at: "2011-03-01 02:46:36">

关于ruby-on-rails-3 - Rails 3 : Multiple has_one associations & seeding，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/5149128/