Ruby on rails Rails有很多：通过-->；如何设置关联以从多个联接模型中提取？

我想通过并行关系建立多个has\u many。以下是我的2个标准和2个连接模型：

User.rb

has_many :ownerships, dependent: :destroy
has_many :devices, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :devices, through: :bookings

belongs_to :user, touch: true, counter_cache: :devices_count
belongs_to :device, touch: true

belongs_to :user, touch: true, counter_cache: :bookings_count 
belongs_to :device, touch: true, counter_cache: :bookings_count

has_many :ownerships, dependent: :destroy
has_many :users, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :users, through: :bookings

has_many :ownerships, dependent: :destroy
has_many :device_ownerships, through: :ownerships, class_name: "Device", foreign_key: "device_id", source: :device

has_many :bookings, dependent: :destroy
has_many :device_bookings, through: :bookings, class_name: "Device", foreign_key: "device_id", source: :device

has_many :ownerships, dependent: :destroy
has_many :user_ownerships, through: :ownerships, class_name: "User", foreign_key: "user_id", source: :user

has_many :bookings, dependent: :destroy
has_many :user_bookings, through: :bookings, class_name: "User", foreign_key: "user_id", source: :user

所有权.rb

has_many :ownerships, dependent: :destroy
has_many :devices, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :devices, through: :bookings

belongs_to :user, touch: true, counter_cache: :devices_count
belongs_to :device, touch: true

belongs_to :user, touch: true, counter_cache: :bookings_count 
belongs_to :device, touch: true, counter_cache: :bookings_count

has_many :ownerships, dependent: :destroy
has_many :users, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :users, through: :bookings

has_many :ownerships, dependent: :destroy
has_many :device_ownerships, through: :ownerships, class_name: "Device", foreign_key: "device_id", source: :device

has_many :bookings, dependent: :destroy
has_many :device_bookings, through: :bookings, class_name: "Device", foreign_key: "device_id", source: :device

has_many :ownerships, dependent: :destroy
has_many :user_ownerships, through: :ownerships, class_name: "User", foreign_key: "user_id", source: :user

has_many :bookings, dependent: :destroy
has_many :user_bookings, through: :bookings, class_name: "User", foreign_key: "user_id", source: :user

Booking.rb

has_many :ownerships, dependent: :destroy
has_many :devices, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :devices, through: :bookings

belongs_to :user, touch: true, counter_cache: :devices_count
belongs_to :device, touch: true

belongs_to :user, touch: true, counter_cache: :bookings_count 
belongs_to :device, touch: true, counter_cache: :bookings_count

has_many :ownerships, dependent: :destroy
has_many :users, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :users, through: :bookings

has_many :ownerships, dependent: :destroy
has_many :device_ownerships, through: :ownerships, class_name: "Device", foreign_key: "device_id", source: :device

has_many :bookings, dependent: :destroy
has_many :device_bookings, through: :bookings, class_name: "Device", foreign_key: "device_id", source: :device

has_many :ownerships, dependent: :destroy
has_many :user_ownerships, through: :ownerships, class_name: "User", foreign_key: "user_id", source: :user

has_many :bookings, dependent: :destroy
has_many :user_bookings, through: :bookings, class_name: "User", foreign_key: "user_id", source: :user

设备.rb

has_many :ownerships, dependent: :destroy
has_many :devices, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :devices, through: :bookings

belongs_to :user, touch: true, counter_cache: :devices_count
belongs_to :device, touch: true

belongs_to :user, touch: true, counter_cache: :bookings_count 
belongs_to :device, touch: true, counter_cache: :bookings_count

has_many :ownerships, dependent: :destroy
has_many :users, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :users, through: :bookings

has_many :ownerships, dependent: :destroy
has_many :device_ownerships, through: :ownerships, class_name: "Device", foreign_key: "device_id", source: :device

has_many :bookings, dependent: :destroy
has_many :device_bookings, through: :bookings, class_name: "Device", foreign_key: "device_id", source: :device

has_many :ownerships, dependent: :destroy
has_many :user_ownerships, through: :ownerships, class_name: "User", foreign_key: "user_id", source: :user

has_many :bookings, dependent: :destroy
has_many :user_bookings, through: :bookings, class_name: "User", foreign_key: "user_id", source: :user

当前设置未按预期工作，连接模型之间似乎存在串扰。我希望连接模型是独立的和并行的（即用户可以与设备建立关系（所有权），而不需要预订设备）。我不是在寻找一个嵌套的多：通过关系在这里

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当我改变一台设备的用户所有权，这似乎改变了预订数量，反之亦然。。。关于如何正确设置，您有什么想法吗？

我认为您遇到的第一个错误是，您使用相同的名称调用了两个关联（

用户

/

设备

）

为了帮助更多的受访者，真正的问题是-->

如何设置关联以从多个加入模型中提取？

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快速修复

Rails关联主要由它们的类命名，但是由于冲突，您应该避免设置它们两次。这就是你看到当前问题的原因。一个简单的解决方案是用不同的名称来称呼协会：

User.rb
has_many :ownerships, dependent: :destroy
has_many :owner_devices, through: :ownerships, class_name: "Device", foreign_key: "ownership_id"

has_many :bookings, dependent: :destroy
has_many :booking_devices, through: :ownerships, class_name: "Device", foreign_key: "booking_id"

---

我仍在寻找有关如何设置关联以使用两种模型的信息

根据Rich Peck的建议，这似乎是一个可行的解决方案：

User.rb

has_many :ownerships, dependent: :destroy
has_many :devices, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :devices, through: :bookings

belongs_to :user, touch: true, counter_cache: :devices_count
belongs_to :device, touch: true

belongs_to :user, touch: true, counter_cache: :bookings_count 
belongs_to :device, touch: true, counter_cache: :bookings_count

has_many :ownerships, dependent: :destroy
has_many :users, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :users, through: :bookings

has_many :ownerships, dependent: :destroy
has_many :device_ownerships, through: :ownerships, class_name: "Device", foreign_key: "device_id", source: :device

has_many :bookings, dependent: :destroy
has_many :device_bookings, through: :bookings, class_name: "Device", foreign_key: "device_id", source: :device

has_many :ownerships, dependent: :destroy
has_many :user_ownerships, through: :ownerships, class_name: "User", foreign_key: "user_id", source: :user

has_many :bookings, dependent: :destroy
has_many :user_bookings, through: :bookings, class_name: "User", foreign_key: "user_id", source: :user

Booking.rb（加入模式）

所有权.rb（加入模型）

设备.rb

has_many :ownerships, dependent: :destroy
has_many :devices, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :devices, through: :bookings

belongs_to :user, touch: true, counter_cache: :devices_count
belongs_to :device, touch: true

belongs_to :user, touch: true, counter_cache: :bookings_count 
belongs_to :device, touch: true, counter_cache: :bookings_count

has_many :ownerships, dependent: :destroy
has_many :users, through: :ownerships

has_many :bookings, dependent: :destroy
has_many :users, through: :bookings

has_many :ownerships, dependent: :destroy
has_many :device_ownerships, through: :ownerships, class_name: "Device", foreign_key: "device_id", source: :device

has_many :bookings, dependent: :destroy
has_many :device_bookings, through: :bookings, class_name: "Device", foreign_key: "device_id", source: :device

has_many :ownerships, dependent: :destroy
has_many :user_ownerships, through: :ownerships, class_name: "User", foreign_key: "user_id", source: :user

has_many :bookings, dependent: :destroy
has_many :user_bookings, through: :bookings, class_name: "User", foreign_key: "user_id", source: :user

---

老实说，我有点困惑为什么外键需要设置成现在的样子，所以我必须多读一点。否则，它似乎是功能性的，我再也看不到这些连接模型之间的串扰了。

感谢您的回答，我认为它走上了正确的轨道。您确定外键正确吗？它们不应该分别是所有权id和预订id吗？没问题-不，我不确定它们是否正确：）我会看一看！这只是一个快速解决方案；至于为一个关联提供多组数据，我需要了解这一点。检查我发布的答案，我将首先尝试并使用它。但我认为这是它的要点，肯定需要别名和类名称的引用。现在只需要找出正确的外国身份证就行了。如果有效，请告诉我。如果您遇到错误/问题，请告诉我&我们可以解决它。回答“深度”问题的一个问题是，我必须重新创建您的环境以评估响应等；我更愿意让询问者做一些事情，因为我们正在努力修复他们的设置！很好-如果您使用非常规关联，那么

外键基本上是一个定义正确列名的变量。最好将关联视为方法，它具有从名称派生的自动选项。如果您使用的是非标准名称，您的论点需要修改为sui t:）顺便说一句，如果我的答案有帮助，您可能希望对其进行更新投票；）