鏈接到另一個表的記錄的設計字段

Question

我正在爲航空公司路由定義數據結構。

預期使用會像

Route.find(1).from_airport # NRT 
Route.find(1).to_airport # KIX 
Route.find(2).from_airport # NRT 
Route.find(2).to_airport # TPE 

不過，我不想定義FROM_AIRPORT字段或TO_AIRPORT字段的字符串值。

將機場數據保存在機場表中。

如何在Ruby on Rails中定義它？

它屬於路由表上的has_one邏輯，機場沒有belongs_to邏輯。

型號：路線（在我的思想）

has_one :from_airport, foreign_key: "id??", class_name: "Route" 
has_one :to_airport, foreign_key: "id??", class_name: "Route" 

機場表

id:1 name: NRT, city: TOKYO, country: JAPAN 
id:2 name: KIX, city: OSAKA, country: JAPAN 

路由表

from_airport: # it should NOT be a string, it should refers to a record in Airports table eg: airport (id:1) 
to_airport: # it should NOT be a string, it should refers to a record in Airports table eg: airport (id:1) 

Answer 1

這是你在尋找什麼？

# routes.rb 
belongs_to :from_airport, foreign_key: :from_airport_id, class_name: "Airport", primary_key: :id 
belongs_to :to_airport, foreign_key: :to_airport_id, class_name: "Airport", primary_key: :id