Question

我有多个关联：

User

class User < ActiveRecord::Base
  has_one :family_tree, dependent: :destroy
  has_many :memberships, dependent: :destroy
  has_many :nodes, dependent: :destroy
  has_many :participants, dependent: :destroy
  has_many :comments

Node

class Node < ActiveRecord::Base
  include PublicActivity::Model
  tracked except: :update, owner: ->(controller, model) { controller && controller.current_user }

  belongs_to :family_tree
  belongs_to :user
  belongs_to :media, polymorphic: true, dependent: :destroy
  has_many :comments, dependent: :destroy
  has_many :node_comments, dependent: :destroy

Notification

class Notification < PublicActivity::Activity
  acts_as_readable :on => :created_at
end

我正在使用public_activity gem，当我在ApplicationController中执行此操作时：

  @unread_act = Notification.where(owner_id: current_user).includes(trackable: { user: :node}).unread_by(current_user)

我收到此错误：

ActiveRecord::AssociationNotFoundError at /
Association named 'node' was not found on User; perhaps you misspelled it?

即使我尝试过这款Vanilla版本：

  @unread_act = Notification.where(owner_id: current_user).includes(:node).unread_by(current_user)

我收到了这个错误：

ActiveRecord::AssociationNotFoundError at /
Association named 'node' was not found on Notification; perhaps you misspelled it?

导致这种情况的原因是什么？

修改1

当我尝试执行includes(:trackable)时，鉴于我正在使用bullet gem，尝试追踪N + 1错误，我收到了此消息：

N+1 Query detected
  Node => [:user]
  Add to your finder: :include => [:user]

N+1 Query detected
  Node => [:media]
  Add to your finder: :include => [:media]
N+1 Query method call stack

所以我正在做的就是尝试减少这些N + 1查询问题。

Answer 1

似乎正确的方法是在trackable属性上使用数组，如下所示：

@unread_act = Notification.where(recipient_id: current_user).includes(:trackable => [:user, :node]).unread_by(current_user).order("created_at desc")

主要部分是：

includes(:trackable => [:user, :node])

这似乎很有效。

Answer 2

Node是PublicActivity条款中的trackable对象。它是一种多态关联，允许您使用Node类以及任何其他模型。

这就是为什么你应该尝试includes(:trackable)的原因。使用控制器中的示例：@unread_act = Notification.where(owner_id: current_user).includes(trackable: { user: :nodes}).unread_by(current_user)。

另请注意，您从Notification派生了自己的PA::Activity课程，这可能无法与acts_as_readable一起使用。尝试使用p_a wiki来学习如何扩展课程。

协会命名未找到，也许你拼错了吗？

2 个答案: