I use NodeJS to insert documents in MongoDB. Using collection.insert I can insert a document into database like in this code:
// ...
collection.
I actually did a console.log() for the second parameter in the callback function for insert. There is actually a lot of information returned apart from the inserted object itself. So the code below explains how you can access it's id.
collection.insert(objToInsert, function (err, result){
if(err)console.log(err);
else {
console.log(result["ops"][0]["_id"]);
// The above statement will output the id of the
// inserted object
}
});