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!
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 $inc documentation
With mongoose version 5 an additional option "useFindAndModify" is needed:
// Make Mongoose use mongoDB's `findOneAndUpdate()`. Note that this option is `true`
// by default, you need to set it to false.
mongoose.set('useFindAndModify', false);
Meme.findOneAndUpdate( {_id: res._id},
{$inc : {'UID' : 1}},
{new: true},
function(err, response) {
// do something
});
Meme.findOneAndUpdate({ _id: res._id }, { $inc: {'post.like': 1 } }, {new: true },function(err, response) {
if (err) {
callback(err);
} else {
callback(response);
}