ruby-on-rails - 请按语法排序 Mongoid Scope

Question

我用的是最新的mongoid...

我该如何做这个名为_scope的事件记录的mongoid等效项:

class Comment
  include Mongoid::Document
  include Mongoid::Timestamps

  embedded_in :post

  field :body, :type => String

  named_scope :recent, :limit => 100, :order => 'created_at DESC'
...
end

Answer 1

必须这样定义

scope :recent, order_by(:created_at => :desc).limit(100)

您可以查看范围的 mongoid 文档 here

从页面

命名作用域是在类级别使用作用域宏定义的，并且可以链接起来以在良好的 DSL 中创建结果集。

class Person
  include Mongoid::Document
  field :occupation, type: String
  field :age, type: Integer

  scope :rock_n_rolla, where(occupation: "Rockstar")
  scope :washed_up, where(:age.gt => 30)
  scope :over, ->(limit) { where(:age.gt => limit) }
end

# Find all the rockstars.
Person.rock_n_rolla

# Find all rockstars that should probably quit.
Person.washed_up.rock_n_rolla

# Find a criteria with Keith Richards in it.
Person.rock_n_rolla.over(60)