I would update a collection setting the value only if the new values are not null. I have a code like this:
...
var userName = req.body.nome;
var userSurn
You can use mongoose for that by casting req.body to your model,
I assume you have mongoose model called User, and in your controller,
var userModel = new User(req.body);
User.update({_id: req.session.userID}, userModel, {upsert: true}, function(err){
console.log("Error occured!");
});
There is no mongoose tag, but I strongly recomment to use that. For more details;
Mongoose Update
Mongoose Model