MongoDB, update collection field if new value is not null

Question

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 userSurname = req.body.cognome;
 var userAddress = req.body.indirizzo;

 collection.update(
     {_id:ObjectId(req.session.userID)},
     {$set: { nome: userName, cognome: userSurname, indirizzo: userAddress }}
 )

Is there an easy way for doing this?

ANOTHER WAY: if I could take the value req.body.* from the placeholder of the form where I take the data, I could solve the problem.. but is this possible?

Answer 1

You could try something like this:

var objForUpdate = {};

if (req.body.nome) objForUpdate.nome = req.body.nome;
if (req.body.cognome) objForUpdate.cognome = req.body.cognome;
if (req.body.indirizzo) objForUpdate.indirizzo = req.body.indirizzo;

//before edit- There is no need for creating a new variable
//var setObj = { $set: objForUpdate }

objForUpdate = { $set: objForUpdate }

collection.update({_id:ObjectId(req.session.userID)}, objForUpdate )

Answer 2

You can use lodash like this other question: https://stackoverflow.com/a/33432857/4777292

_.pickBy({ a: null, b: 1, c: undefined }, _.identity);

would be

{b:1}