关联名字找不到，也许你拼错了吗？

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 

我现在用的是public_activity宝石，当我做这在我ApplicationController：

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

我得到这个错误：

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

即使当我尝试这样做香草版本：

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

我得到这个错误：

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

有什么事情是造成这个？

编辑1

，当我试图只是做了includes(:trackable)，因为我使用的子弹宝石，试图追查N + 1个错误，我得到这个消息：

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 

因此，我所做的一切都试图减少这些N + 1查询问题。

Answer 1

这似乎解决这个正确的方法是使用在trackable属性这样一个数组：

@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])

这似乎已经奏效精美。

Answer 2

Node是您的trackable对象在PublicActivity条款。这是一个多态关联，可以让您使用您的Node类以及任何其他模型。

这就是为什么你应该尝试includes(:trackable)来代替。以控制器为例：@unread_act = Notification.where(owner_id: current_user).includes(trackable: { user: :nodes}).unread_by(current_user)。

另请注意，您从PA::Activity中派生出自己的Notification类，这可能无法与acts_as_readable一起使用。试试p_a wiki以了解如何扩展课程。