Mongoid 3-检查组合键的唯一性 [英] Mongoid 3 - Check for uniqueness of composite key

问题描述

我切换到Mongoid 3，这使得一些不同之处:)当前，我尝试检查复合字段是否唯一:

I switched to Mongoid 3 which makes few things different :) Currently I try to check if a composite field is unique:

class Host
  include Mongoid::Document

  field :ip, :type => String
  field :port, :type => Integer
  field :username, :type => String
  field :password, :type => String

  validates_presence_of :ip
  validates_presence_of :port
end

如何在其中获取validates_uniqueness_of，它应该检查ip和port是否作为复合字段唯一? AFAIK在Mongoid 2中提供了一种基于多个字段创建新_id的方法，但似乎在Mongoid 3中已将其删除:

How to get a validates_uniqueness_of therein which should check if ip and port are unique as composite field? AFAIK there was a way in Mongoid 2 to create a new _id based on multiple fields, but it seems, this was removed in Mongoid 3:

  key :ip, :port

推荐答案

在3中删除了复合键支持，因为您现在可以轻松覆盖默认的_id字段并使用lambda设置默认值.尝试类似的东西:

Composite key support was removed in 3, since you can easily override the default _id field now and set a default value with a lambda. Try something like:

class Host
  include Mongoid::Document
  field :_id, type: String, default: -> { ip + ":" + port }
  ...
end

然后您可以验证此_id字段的唯一性.

You can then validate the uniqueness of this _id field.

有关更多信息，请参见Mongoid docs .

See the Mongoid docs for more info.

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