Increment String

[d0d04m3]

hi I need Increment String by one but I cant
sow I convert to number for incremented but nothing

and this

var id = Number(msg.payload[0]._id);
id++;
msg.payload[0].ack_id = (id).toString();
node.send(msg);

not work
any help

[JGKK]

This is because your id string contains letters and not just numbers. So the Number() method returns NaN not a number.
Johannes
Edit here is a link that explains this behavior of the Number() Method https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number

[Steve-Mcl]

If you are using it just to confirm receipt, why not simply return the _id (i.e. why do you have to increment it?)

[d0d04m3]

oh yes am wrong I thought HEX valeu

[d0d04m3]

@Steve-Mcl

If you are using it just to confirm receipt, why not simply return the _id (i.e. why do you have to increment it?)

this NEXT Record from MongoDB
so I need find this id into database for check its present or not

[Steve-Mcl]

Ok,so is that an automatic ID or does your systems generate it?

If it's automatically generated by mongo I'm not certain you can guarantee the next id will be hex+1

[d0d04m3]

this Auto ID generated by mongodb when store any thing

[Steve-Mcl]

Then I'm struggling to understand the logic. Anyhow, assuming it's always alphanumerically greater then can't you select next record(s) where _id I'd greater than _id?

E.g...

db.products.find({_id: {$gt: ObjectId("4fdbaf608b446b0477000142" )}}).sort({_id:1}).limit(1);

[d0d04m3]

ok I am solved with add UUID node generator to any new incoming event and not ACK type of msg
before stored in dB

[d0d04m3]

@Steve-Mcl

Then I'm struggling to understand the logic. Anyhow, assuming it's always alphanumerically greater then can't you select next record(s) where _id I'd greater than _id?

E.g...

yes its logic to work

[d0d04m3]

but I see this error

[Steve-Mcl]

Actually, not sure how you'd do this ina function node.

Normally in a nodejs project ObjectId is imported

E.g. var ObjectId = require('mongodb').ObjectID;

Does the mongo nodes have a find node? Or a means of accessing ObjectId?

Sorry, I don't know how to help here.