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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