Rails属于双向

Question

我有一张样板机票和一张样板收据。收据具有属性ticket_id。

receipt.rb

belongs_to :ticket

一张收据总是只有一张票，而一张票只有一张收据。

现在我可以打电话给receive.ticket。但是我打不了ticket.receipt。

有没有一种方法可以在不向Ticket添加票证属性的情况下实现？

Answer 1

has_one

receipt.rb

belongs_to :ticket

ticket.rb

has_one :receipt
#has_one :receipt, class_name: "Receipt", foreign_key: "ticket_id"

..

#receipt.ticket =>  Returns the associated ticket. nil is returned if none is found.
#ticket.receipt =>  Returns the associated receipt. nil is returned if none is found.

Answer 2

在ticket.rb中，添加：

has_one :receipt