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

Hey there, did you salve to mongo? if it is returning null, maybe because the dataset is empty. Try something like `console(Sequence.find())`, and you will see all the documents before trying to get information from then, and make sure the document is saved. — Jorge Guerra Pires, Mar 14 '20 at 08:30
I see you are printing the found document here `console.log(ret.TICKET_NO)`, what do you see? — Jorge Guerra Pires, Mar 14 '20 at 08:31
getting `Query { _mongooseOptions: {}, _transforms: [], _hooks: Kareem { _pres: Map {}, _posts: Map {} }, _executionCount: 0, ..........` — Sufail Kalathil, Mar 14 '20 at 11:02
can you let us know what you see when you do the comment `console(Sequence.find())`? — Jorge Guerra Pires, Mar 14 '20 at 11:41
As you can see from your comment, something is wrong, it supposes to return something when you do `console.log(ret.TICKET_NO)` — Jorge Guerra Pires, Mar 14 '20 at 11:43
please, see this question https://stackoverflow.com/questions/56088835/how-do-i-get-data-from-mongodb — Jorge Guerra Pires, Mar 14 '20 at 11:44
Are you using mongoose?? See here: https://mongoosejs.com/docs/tutorials/findoneandupdate.html there is a difference in findOneAndUpdate — Jorge Guerra Pires, Mar 14 '20 at 11:53
@JorgePires Mate, it's just a callback issue. Async/await will solve it. — Nilesh Singh, Mar 14 '20 at 11:54

Nilesh Singh · Accepted Answer · 2020-03-14T16:13:33.337

0

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
            }
          });
     );
}

edited Mar 14 '20 at 16:13

answered Mar 14 '20 at 11:47

Nilesh Singh

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both methods are working.but TICKET_NO on the sequence collection is not updating always getting the same ticket no. Kindly help to resolve the same – Sufail Kalathil Mar 14 '20 at 15:15
What is the. TICKET_NO that you're getting? – Nilesh Singh Mar 14 '20 at 15:20
`{id:"TICKET_ID", TICKET_NO:7 }`.. ticket_no should be increment by 1 on each call.unfrtntly it is not updating on the database. so function always return 7 as ticket_no – Sufail Kalathil Mar 14 '20 at 15:33
Updated answer to reflect changes. Your options, i.e, `new: true` was not valid, as it was not in the correct format. The changes should work. – Nilesh Singh Mar 14 '20 at 16:13

Auto-Incrementing Sequence Field Mean Stack

1 Answers1