多对多持久性 ruby​​ mongoid

Question

这是我的第一篇文章，如果我没有给你足够的信息，请告诉我

所以，我正在尝试 ruby​​1.9.2 并将 mongoid2.2.0 与 mongodb1.8.2 一起使用，但我无法在代码中以多对多关系持久化数据库文档。

require 'mongoid'
require 'mongo'

Mongoid.load!("../Configurations/mongoid.yml")

Mongoid.configure do |config|
  config.master = Mongo::Connection.new.db("godfather")
end

connection = Mongo::Connection.new
connection.drop_database("godfather")
database = connection.db("godfather")

class Project
  include Mongoid::Document
  field :name, type: String
  key :name
  field :numPeople, type: Integer
  has_and_belongs_to_many :people
end

class Person
  include Mongoid::Document
  field :name, type: String
  key :name
  field :numProjects, type: Integer, default: 0
  has_and_belongs_to_many :projects

  def add_project(project_name)
    project = Project.create(name: project_name)
    self.numProjects = self.numProjects + 1
    self.projects << project
    self.save
  end
  def has_project?(project_name)
    self.projects.each do |project|
      if project.name.upcase == project_name.upcase
        return true
      end
    end
    return false
  end
end

database = Project.create(name: "Database")

alice = Person.create(name: "Alice")
alice.add_project("Database")
puts "has project? #{alice.has_project?("Database")}"#outputs true


puts "Alice has #{alice.numProjects} projects"#outputs 1 
puts "Alice really has #{alice.projects.size} projects"#outputs 1 

editor = Project.create(name: "Editor")

john = Person.create(name: "John")
john.has_project?("Editor")
john.add_project("Editor")
puts "has project? #{john.has_project?("Editor")}"#outputs false

puts "John has #{john.numProjects} projects"#outputs 1 
puts "John really has #{john.projects.size} projects"#outputs 0

operatingSystem = Project.create(name: "OperatingSystem")
drinking = Project.create(name: "Drinking")

henry = Person.create(name: "Henry")
henry.add_project("OperatingSystem")
henry.has_project?("OperatingSystem")
henry.add_project("drinking")
henry.add_project("Editor")

puts "Henry has #{henry.numProjects} projects"#outputs 3
puts "Henry really has #{henry.projects.size} projects"# outputs 3

所以问题是当我添加一个项目时，约翰输出他有 0 个项目。

奇怪的是，当我使用 mongo 终端检查数据库时，它显示 john 拥有一个项目“Editor”，而代码在 john.projects.size 中找不到该项目。

理想情况下，我调用 add_project 和 has_project 的顺序是什么？不应影响代码和事项。

• 谢谢

Answer 1

看不出您的代码有什么问题，但我得到的结果与您在此处运行的结果相同。

看起来这可能是一个已知问题 - https://github.com/mongoid/mongoid/issues/1198

Answer 2

尝试将自动保存设置为 true

查看：http://mongoid.org/docs/upgrading.html（在页面上搜索自动保存）