nodejs mongoose change existing documents code example

Example 1: mongoose find and update prop

var query = {'username': req.user.username};
req.newData.username = req.user.username;

MyModel.findOneAndUpdate(query, req.newData, {upsert: true}, function(err, doc) {
    if (err) return res.send(500, {error: err});
    return res.send('Succesfully saved.');
});

Example 2: mongoose updateone example

// Update the document using `updateOne()`
await CharacterModel.updateOne({ name: 'Jon Snow' }, {
  title: 'King in the North'
});

// Load the document to see the updated value
const doc = await CharacterModel.findOne();
doc.title; // "King in the North"