How to query against ObjectId when not in mongo shell

Question

I'm working on paging functionality using a range query. I'm using this test query in the mongo shell:

> var params =  {$query: {_id: {$lt: ObjectId("52b06166eff887999c6efbd9")}}, $orderby: {_id: -1}, $maxScan: 3}
> params
{
  "$query" : {
    "_id" : {
      "$lt" : ObjectId("52b06166eff887999c6efbd9")
    }
  },
  "$orderby" : {
    "_id" : -1
  },
  "$maxScan" : 3
}
> db.events.find(params)

I'd like to be able to pass the serialized params object to a web service (as a URL query string). However, the ObjectId class is only available inside the shell. Is there a way to specify an ObjectId as part of a query when not in the shell? I've tried the following as the value of $lt without success:

'ObjectId("52b06166eff887999c6efbd9")'
'new ObjectId("52b06166eff887999c6efbd9")'
{"$oid" : "52b06166eff887999c6efbd9"}

Answer 1

Generally speaking, this abstraction is handled by whatever MongoDB driver you use. If you are using an actual driver, you can do queries on _id without using ObjectId()

Mongoose / Node.js Example:

People.find({ _id : "Valid ObjectID String" }, function(e, person) {
  console.log(e, person);
});

If you do still need the ObjectId helper, generally you are able to reference it in whatever native driver you need.

Answer 2

What you are doing in your last examples is passing your objectId as a string (first two examples) or as a dictionary third example. So surely it does not work.

You can pass just a string '52b06166eff887999c6efbd9' as a parameter and then when you receive it you can construct normal ObjectId on the server. For example in php you can construct it in the following way new MongoId('your string');