mongoose Model.update() - only update provided values

Question

I have the following schema:

const wordSchema = mongoose.Schema({
  author: {type: String, index: true, default: 'unknown'},
  quote: String,
  source: {type: String, default: 'unknown', index: true},
  rating: {type: Number, default: 0},
  createdAt: {type: Date, default: Date.now},
  updatedAt: {type: Date, default: Date.now},
});

And the following PUT route in my express app:

// Route to update a quote in the DB
app.put('/words/:id', function(req, res) {
  const quote = new Word({
    _id: req.params.id,
    author: req.body.author,
    quote: req.body.quote,
    source: req.body.source,
    rating: req.body.rating,
    updatedAt: Date.now(),
  });
  Word.update(quote, function(err, raw) {
    if (err) {
      res.send(err);
    }
    res.send(raw);
  });
});

Now when I send the PUT request, if the parameters set with a default value are not provided, they will be filled with the default values from the Schema. How do I update only the provided values?

Thanks for the help.

Answer 1

Don't create a new Word instance for the update, update takes conditions and doc object parameters that let you separately identify the document to update and provide its updated values:

app.put('/words/:id', function(req, res) {
  const doc = {
    author: req.body.author,
    quote: req.body.quote,
    source: req.body.source,
    rating: req.body.rating,
    updatedAt: Date.now(),
  });
  Word.update({_id: req.params.id}, doc, function(err, raw) {
    if (err) {
      res.send(err);
    }
    res.send(raw);
  });
});

Answer 2

You can try using the Model.findByIdAndUpdate() method where all top level update keys which are not atomic operation names are treated as set operations and defaults/setters are never executed. You can use lodash's _.assign() method to set the updatedAt field:

// Route to update a quote in the DB
app.put('/words/:id', function(req, res) {
    const update = _.assign({ "updatedAt": new Date() }, req.body);
    Word.findByIdAndUpdate(req.params.id, update, function(err, raw) {
        if (err) {
            res.send(err);
        }
        res.send(raw);
    });
});