Auto-Incrementing Sequence Field Mean Stack

Question

I have a collection created for maintaining ticket_no, for which document looks like this,

{
  id:"TICKET_ID",
  TICKET_NO:7
}

Now, when I try to findOneAndUpdate for a ticket_id, incrementing TICKET_NO by 1,

function get(){
     var ret = Sequence.findOneAndUpdate(
            {
                query: { _id: 'TICKET_ID' },
                update: { $inc: { TICKET_NO: 1 } },
                new: true
            }
        );

        console.log(ret.TICKET_NO)
        return ret.TICKET_NO;
}

The function returns null value instead of ticket no

Answer 1

What you are getting in ret is the findOneAndUpdate function object, not your actual document.

You need to listen to callback or use async/await for the value to be there,

Try one of these,

async function get(){
     var ret = await Sequence.findOneAndUpdate(
          { _id: 'TICKET_ID' },
          { $inc: { TICKET_NO: 1 } },
          { new: true }
     );

     console.log(ret.TICKET_NO) // now the ret is the doc you need
     return ret.TICKET_NO; // prints correctly
}

or,

function get(){
     Sequence.findOneAndUpdate(
          { _id: 'TICKET_ID' },
          { $inc: { TICKET_NO: 1 } },
          { new: true },
          function(err, ret) {
            if (err) {
              console.error(err)
            } else {
              console.log(ret.TICKET_NO) //successful callback returns ret
            }
          });
     );
}