ruby-on-rails - 使用mongoid使用mongodb在消息父级中嵌入消息回复

Question

我认为最好的做法是将对特定消息的回复嵌入到该消息中，我正在尝试使用 mongoid 来实现它。这是我的

class Message
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Paranoia 

  field :subject
  field :body
  field :sender_deleted, :type => Boolean, :default => false
  field :recipient_deleted, :type => Boolean, :default => false
  field :read_at, :type => DateTime

  referenced_in :sender, :class_name => "User", :inverse_of => :sender, :foreign_key => 'sender_id'
  referenced_in :recipient, :class_name => "User", :inverse_of => :recipient, :foreign_key => 'recipient_id'

  embeds_many :replies, :class_name => 'Message'
  embedded_in :message, :inverse_of => :replies

这是我尝试定义消息及其回复关系的部分:

  embeds_many :replies, :class_name => 'Message'
  embedded_in :message, :inverse_of => :replies

它对我不起作用，我不知道为什么，知道我怎么能做这样的事情吗？

Answer 1

这是否是最佳实践是一个备受争议的话题。例如，您必须注意对象大小限制(目前为 4 MB，但很快就会增加)。

关于你的问题: 我建议你改变

  embeds_many :replies, :class_name => 'Message'
  embedded_in :message, :inverse_of => :replies

到

  embeds_many :replies, :class_name => 'Message'
  referenced_in :message

而且您还必须手动指定这两个连接(这应该不是问题，因为它们可能无论如何都是不可变的)。

irb(main):002:0> msg1 = Message.new :subject => 'new question'
=> #<Message _id: 4cc7699f457601d7e8000001, created_at: nil, body: nil, updated_at: nil, subject: "new question", read_at: nil, sender_deleted: false, message_id: nil, recipient_deleted: false>
irb(main):003:0> msg2 = Message.new :subject => 'first comment'
=> #<Message _id: 4cc769b6457601d7e8000002, created_at: nil, body: nil, updated_at: nil, subject: "first comment", read_at: nil, sender_deleted: false, message_id: nil, recipient_deleted: false>
irb(main):005:0> msg2.message = msg1
=> #<Message _id: 4cc7699f457601d7e8000001, created_at: nil, body: nil, updated_at: nil, subject: "new question", read_at: nil, sender_deleted: false, message_id: nil, recipient_deleted: false>
irb(main):007:0> msg1.replies << msg2
=> [#<Message _id: 4cc769b6457601d7e8000002, created_at: nil, body: nil, updated_at: nil, subject: "first comment", read_at: nil, sender_deleted: false, message_id: BSON::ObjectId('4cc7699f457601d7e8000001'), recipient_deleted: false>]
irb(main):008:0> msg1.save
=> true