Mongoose delete array element in document and save

Question

I have an array in my model document. I would like to delete elements in that array based on a key I provide and then update MongoDB. Is this possible?

Here's my attempt:

var mongoose = require('mongoose'),
    Schema = mongoose.Schema;

var favorite = new Schema({
    cn: String,
    favorites: Array
});

module.exports = mongoose.model('Favorite', favorite, 'favorite');

exports.deleteFavorite = function (req, res, next) {
    if (req.params.callback !== null) {
        res.contentType = 'application/javascript';
    }
    Favorite.find({cn: req.params.name}, function (error, docs) {
        var records = {'records': docs};
        if (error) {
            process.stderr.write(error);
        }
        docs[0]._doc.favorites.remove({uid: req.params.deleteUid});

        Favorite.save(function (error, docs) {
            var records = {'records': docs};
            if (error) {
                process.stderr.write(error);
            }
            res.send(records);

            return next();
        });
    });
};

So far it finds the document but the remove nor save works.

Answer 1

You can also do the update directly in MongoDB without having to load the document and modify it using code. Use the $pull or $pullAll operators to remove the item from the array :

Favorite.updateOne({ cn: req.params.name }, {
    $pullAll: {
        favorites: req.params.deleteUid,
    },
});

To remove objects from array then

Favorite.updateOne({ cn: req.params.name }, {
    $pullAll: {
        favorites: [{_id: req.params.deleteUid}],
    },
});

(you can also use updateMany for multiple documents)

http://docs.mongodb.org/manual/reference/operator/update/pullAll/