活动记录的Rails 3联工作不正常 [英] Active Record Rails 3 associations not working properly

问题描述

我有以下类与关联：

class Customer < ActiveRecord::Base
  has_many :orders
  has_many :tickets, :through => :orders
  has_many :technicians, :through => :ticket
  has_many :services, :through => :ticket
end

class Order < ActiveRecord::Base
  belongs_to :customer
  has_many :tickets
  has_many :technicians, :through => :tickets
  has_many :services, :through => :tickets
end  

class Service < ActiveRecord::Base
  has_many :tickets
  has_many :technicians, :through => :tickets
  has_many :orders, :through => :tickets
end  

class Technician < ActiveRecord::Base
  has_many :tickets, :order => 'created_at DESC'
  has_many :services, :through => :tickets
  has_many :orders, :through => :tickets
end  

class Ticket < ActiveRecord::Base
  belongs_to :technician
  belongs_to :service
  belongs_to :order
end  

我可以这样做：
    technician.tickets.service.price

I can do:
technician.tickets.service.price

但我不能这样做：
    customer.orders.technician.name
    customer.orders.last.tickets.technician.name

But I can't do:
customer.orders.technician.name
customer.orders.last.tickets.technician.name

我该如何去从客户的技术人员或服务？

How do I go from customer to technician or service?

推荐答案

现在的问题是，你不能叫一个属性上对象的集合。

The problem is that you cannot call a property on a collection of objects.

customer.orders.technician.name

在这里，您有订单的集合。每个序可以有不同的技术人员。这就是为什么你不能叫技术人员上的集合。

Here you have a collection of orders. Each order could have a different technician. That's why you cannot call technician on a collection.

解决方法：拨打技术人员每个顺序目标：

Solution: call technician on each order object:

customer.orders.each do |order|
  order.technician.name
end

也是一样的你的第二个例子。相反的：

Same goes for your second example. Instead of:

customer.orders.last.tickets.technician.name

使用：

customer.orders.last.tickets.each do |ticket|
  ticket.technician.name
end

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