Rails ActiveRecord協會

Question

我有routes表，字段from_airport_id和to_airport_id。

比方說：

route = Route.find(1) 

的問題是：如何定義ActiveRecord關聯，那route.from_airport就等於Airport.find（route.from_airport_id）和route.to_airport = Airport.find（路線.to_airport_id）？

換句話說：

from_airport_id => airport.id

to_airport_id => airport.id

我猜，查詢應該是：

route = Route.find(1).includes(:airports) 

但是怎麼辦我一次從同一張表中選擇兩條記錄？

Answer 1

has_many :from_airports, :class_name => "AirPort", 
:foreign_key => "from_airport_id" 


has_many :to_airports, :class_name => "AirPort", 
:foreign_key => "to_airport_id"