mongoid 查询轨道 3

Question

MongoDB/mongoid 是全新的，并且

在 Rails 控制台上的 ruby​​/rails 上仍然很绿：

t = Task.all(:conditions  => {:title => "task2"})

=> #<Mongoid::Criteria
selector: {:title=>"task2"},
options:  {},
class:    Task,
embedded: false>


>> t.first
=> #<Task _id: 4d7e2cdb73ec3227dd000009, title: "task2", latitude: 23.987904829, longitude: -12.9423875,  created_by: "4d792d6973ec3248e3000001">

返回我所期望的结果，但

t = Task.where(:created_by => "4d792d6973ec3248e3000001")

=> #<Mongoid::Criteria
selector: {:created_by=>BSON::ObjectId('4d792d6973ec3248e3000001')},
options:  {},
class:    Task,
embedded: false>

>> t.first 
=> nil

结果与以下内容相同：

t = Task.all(:conditions  => {:created_by => "4d792d6973ec3248e3000001"})

这是模型：

class Task
  include Mongoid::Document
  field :title
  field :latitude,                  :type => Float
  field :longitude,                 :type => Float
  field :created_by
end

我做错了什么？

更新的示例：

>> Task.new(:title => "task8", :created_by => "4d792d6973ec3248e3000001")
=> #<Task _id: 4d81037973ec32cc22000003, latitude: nil, longitude: nil, title: "task8", created_by: "4d792d6973ec3248e3000001">

>> t = Task.all(:conditions  => {:created_by => "4d792d6973ec3248e3000001"})
=> #<Mongoid::Criteria
selector: {:created_by=>BSON::ObjectId('4d792d6973ec3248e3000001')},
options:  {},
class:    Task,
embedded: false>

>> t.first 
=> nil

我是否需要将created_by明确定义为：type =>细绳 ？

Answer 1

看起来created_by作为字符串存储在文档中，但随后您查询以查找ObjectId。 ObjectId 和字符串不同。

尝试更改

>> Task.new(:title => "task8", :created_by => "4d792d6973ec3248e3000001")

为

>> Task.new(:title => "task8", :created_by => BSON::ObjectId("4d792d6973ec3248e3000001"))

Answer 2

您必须在 mongoid 中包含此功能，如 docs 中所述：

class Person
  include Mongoid::Document
  include Mongoid::Timestamps
end