Duplicate a document in MongoDB using a new _id

Question

Ok, I suppose that this is a silly question and probably has a simple answer.

How can I duplicate a document in MongoDB, changing the _id of the new one?

Imaging that you have the original document:

> var orig = db.MyCollection.findOne({_id: 'hi'}) 

And now I want another document in the collection with _id 'bye'.

Answer 1

Just change the id and re-insert.

> db.coll.insert({_id: 'hi', val: 1}) > var orig = db.coll.findOne({_id: 'hi'}) > orig._id = 'bye' bye > db.coll.insert(orig) > db.coll.find() { "_id" : "hi", "val" : 1 } { "_id" : "bye", "val" : 1 } 

Answer 2

You can give a new ObjectId to the copy Document. In mongo shell

var copy = db.collection.findOne(); for (var i = 0; i< 30; i++){      copy._id = new ObjectId();      db.collection.insert(copy); }