Question

我在Rails 3应用程序中有Flight，Person和Glider模型。我已经定义了自定义关系，因为我需要多个外键引用来自flight表的Person。协会只能以单向工作。

class Flight < ActiveRecord::Base
  belongs_to :pilot, :class_name => "Person"
  belongs_to :instructor, :class_name => "Person"
  belongs_to :towplane_pilot, :class_name => "Person"
  belongs_to :airplane_instructor, :class_name => "Person"

  belongs_to :glider
  belongs_to :rep_glider, :class_name => "Glider"

  belongs_to :departure_airfield, :class_name => "Airfield"
  belongs_to :arrival_airfield, :class_name => "Airfield"

end

class Glider < Aircraft
  has_many :flights
  has_many :replaced_flights, :foreign_key => "rep_glider_id", :class_name => "Flight"
end

class Person < ActiveRecord::Base
  has_many :flights, :foreign_key => "pilot_id", :class_name => "Flight"
  has_many :instructed_flights, :foreign_key => "instructor_id", :class_name => "Flight"
  has_many :towed_flights, :foreign_key => "towplane_pilot_id", :class_name => "Flight"
  has_many :instructed_towing_flights, :foreign_key => "airplane_instructor_id", :class_name => "Flight"
end

####What works#####
Flight.first.glider
Flight.first.rep_glider
Flight.first.pilot 
Flight.first.instructor 
Flight.first.towplane_pilot
Flight.first.airplane_instructor

Glider.first.flights 
Glider.first.replaced_flights    

####What doesn't work#### ----> NoMEthodError 'match'
Person.first.flights
Person.first.instructed_flights
Person.first.towed_flights.
Person.first.instructed_towing_flights

我差不多了，但我不明白当Glider.first.flights没有Person.first.flights时class Airfield < ActiveRecord::Base has_many :takeoff_flights, :foreign_key => "departure_airfield_id", :class_name => "Flight" has_many :grounded_flights, :foreign_key => "arrival_airfield_id", :class_name => "Flight" end ###Works Correctly Airfield.first.takeoff_flights Airfield.first.grounded_flights Flight.first.departure_airfield Flight.first.arrival_airfield如何运作。

更新：与'机场'的关联工作...所以我对于为什么它不能与'人'合作

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Answer 1

您的飞行员有类型吗？像pilot_type列一样？我也开始阅读这些模式，幸运的是它仍然有点新鲜（希望如果我是wron rails ninjas，请纠正我！））

您需要这里讨论的多态模式：

http://asciicasts.com/episodes/154-polymorphic-association

Answer 2

我被告知这些模型之间的关联设置正确。

我在航班表中添加了一条新记录，现在这些协会可以正常使用这条新记录以及之前的所有记录。我现在不确定它是如何工作的，但确实如此。

Rails两个模型之间的多个关联

2 个答案: