How do I increment a Number value in Mongoose?

Question

People of StackOverflow, I am burning with the question, how do I increment a
Number value in Mongoose? I have tried the code below, though it is not working. I am trying to increment a value by one on the submission of a form. Below is my code:

app.post('/like', function (req, res) {     var id = req.body.id;     var query = {_id: id};     var post = Meme.findOne(query);     Meme.findOneAndUpdate(post, post.likes: post.likes+1) }); 

Thanks so much for your valuable help!

Answer 1

You can use $inc for this purpose.

Try this:

var id = req.body.id; Meme.findOneAndUpdate({_id :id}, {$inc : {'post.likes' : 1}}).exec(...); 

For more info on $inc, Please read MongoDB $inc documentation

Answer 2

With mongoose version 5 an additional option "useFindAndModify" is needed:

 // Make Mongoose use mongoDB's `findOneAndUpdate()`. Note that this option is `true`  // by default, you need to set it to false.  mongoose.set('useFindAndModify', false);    Meme.findOneAndUpdate( {_id: res._id},        {$inc : {'UID' : 1}},        {new: true},        function(err, response) {             // do something       }); 

Mongoose Depreciation Doc