使用Ruby检索唯一记录将MongoDB _id转换为ObjectID对象(Turn MongoDB _id into an ObjectID object using Ruby to Retrieve Unique Record)

 我正在尝试使用标准类型ObjectID的_id检索存储在MongoDB中的文档。 我将_id表示为字符串。 在这个例子中它是“4ec064e406a6f1205a000001” 
 
 所以我这样做： 
 
require 'mongo'

connection = Mongo::Connection.new("localhost", 27017).db("store")
collection = connection.collection("products")

id = '4ec064e406a6f1205a000001'

# What should the following line be? This doesn't work.
collection.find_one("_id" => Mongo::ObjectID.from_string(id))
 
 我意识到这是一个BSON ObjectID，我尝试了一些不同的方法来使用bson gem生成正确的对象，但我无法让它工作。 我也尝试使用类似的代码将对象的_id中的一个更改为标准的Int32，并且它工作正常。 我不知道如何创建用于此查询的正确ObjectID对象。 
 
 谢谢！ 

I'm trying to retrieve a document stored in MongoDB using its _id of the standard type ObjectID. I have the _id represented as a string. In this example it's "4ec064e406a6f1205a000001"
 
So I do:
 
require 'mongo'

connection = Mongo::Connection.new("localhost", 27017).db("store")
collection = connection.collection("products")

id = '4ec064e406a6f1205a000001'

# What should the following line be? This doesn't work.
collection.find_one("_id" => Mongo::ObjectID.from_string(id))
 
I realize this is a BSON ObjectID and I tried some different ways of using the bson gem to generate the right object but I can't get it to work. I also tried to change one of the object's _id to a standard Int32 using similar code and it worked fine. I don't know how to create the right ObjectID object to use with this query.
 
Thanks!

原文：https://stackoverflow.com/questions/8116414