Does Mongoose support the Mongodb `findAndModify` method?

Question

I would like to use findAndModify to atomically increment a field, using Mongoose.

However, the code below throws the error \"TypeError: Object # has no method \'fin

Answer 1

In version 3, the mongoose findOneAndUpdate method exposes mongodb's findAndModify operation. It works like so:

var query = { name: 'Sprinkls' };
var update = { name: 'Sprinkles' };
var options = { new: false };
Cat.findOneAndUpdate(query, update, options, function (err, cat) {
  if (err) ..
  render('cat', cat);
});

More info here: http://aaronheckmann.tumblr.com/post/48943524629/mongoose-v3-part-2-findandmodify

Answer 2

This is fully supported in Mongoose 3.x now, though the name is slightly different.

http://mongoosejs.com/docs/api.html#model_Model.findOneAndUpdate

http://mongoosejs.com/docs/api.html#model_Model.findByIdAndUpdate

http://mongoosejs.com/docs/api.html#model_Model.findOneAndRemove

http://mongoosejs.com/docs/api.html#model_Model.findByIdAndRemove

Answer 3

The feature is not well (read: at all) documented, but after reading through the source code, I came up with the following solution.

Create your collection schema.

var Counters = new Schema({
  _id: String,
  next: Number     
});

Create a static method on the schema which will expose the findAndModify method of the model's collection.

Counters.statics.findAndModify = function (query, sort, doc, options, callback) {
  return this.collection.findAndModify(query, sort, doc, options, callback);
};

Create your model.

var Counter = mongoose.model('counters', Counters);

Find and modify!

Counter.findAndModify({ _id: 'messagetransaction' }, [], { $inc: { next: 1 } }, {}, function (err, counter) {
  if (err) throw err;
  console.log('updated, counter is ' + counter.next);
});

Bonus

Counters.statics.increment = function (counter, callback) {
  return this.collection.findAndModify({ _id: counter }, [], { $inc: { next: 1 } }, callback);
};

Counter.increment('messagetransaction', callback);

Answer 4

I would suggest using the direct command style shown at the bottom of http://www.mongodb.org/display/DOCS/findAndModify+Command. I'm not familiar enough with mongoose to know the method for running a command, but all drivers provide some way to do it. If mongoose doesn't, you can do it directly using the style described at the top of http://www.mongodb.org/display/DOCS/Commands.

That said, you should make sure that you really need findAndModify and that update won't do what you need it to do. To see what update is capable of take a look at http://www.mongodb.org/display/DOCS/Updating.

Answer 5

Taking the above response from @furf, this is my promised solution:

// eslint-disable-next-line func-names
localeTypesSchema.statics.findAndModify = function (query, sort, update, opts, callback) {
    const cb = callback || (() => { });
    try {
        const result = this.collection.findAndModify(query || {}, sort || [], update || {}, opts);
        cb(null, result);
        return Promise.resolve(result);
    } catch (err) {
        cb(err);
        return Promise.reject(err);
    }
};

Answer 6

Made working version increment for Mongoose 3.x

var mongoose = require('mongoose');

var CounterSchema = new mongoose.Schema({
    _id: String,
    next: {type: Number, default: 1}
});

CounterSchema.statics.increment = function (counter, callback) {
    return this.findByIdAndUpdate(counter, { $inc: { next: 1 } }, {new: true, upsert: true, select: {next: 1}}, callback);
};

Use something like this:

Counter.increment('photo', function (err, result) {
    if (err) {
        console.error('Counter on photo save error: ' + err); return;
    }
    photo.cid = result.next;
    photo.save();
});

I hope someone come in handy