Auto Increment Sequence Mongoose

Question

I implemented a auto increment sequence field in mongoose. I set the default/starting value as 5000. But it does not start from 5000, it starts from 1.

Heres my code:

My Counter Schema

// app/models/caseStudyCounter.js
// load the things we need
var mongoose = require('mongoose');
var bcrypt   = require('bcrypt-nodejs');

// define the schema for our user model
var caseStudyCounterSchema = mongoose.Schema({
   _id: {type: String, required: true},
   seq: {type: Number, default: 5000}

});

// methods ======================

// create the model for users and expose it to our app
module.exports = mongoose.model('caseStudyCounter', caseStudyCounterSchema);

My Main Schema:

// grab the mongoose module
var caseStudyCounter = require('../models/caseStudyCounter');
var mongoose = require("mongoose");

// grab the bcrypt module to hash the user passwords
var bcrypt   = require('bcrypt-nodejs');

// define the schema for our model
var caseStudySchema = mongoose.Schema({
     caseStudyNo: Number,
     firstName: String,
     lastName: String,

 });

caseStudySchema.pre('save', function(next) {
  var doc = this;

caseStudyCounter.findByIdAndUpdate({_id: 'caId'},{$inc: { seq: 1}},{"upsert": true,"new": true  }, function(error, counter)   {
    if(error)
        return next(error);
    doc.caseStudyNo = counter.seq;
    next();
});

});
 // module.exports allows us to pass this to other files when it is called
 // create the model for users and expose it to our app
 module.exports = mongoose.model('CaseStudy', caseStudySchema);

I can't figure out why its starting form 1 when I have set the default as 5000. The sequence should be 5001, 5002, 5003 and so on. Any help will be greatly appreciated.

you can install this module [mongoose-auto-increment](https://www.npmjs.com/package/mongoose-auto-increment) — morels, Jun 15 '16 at 10:00
you can create before to get find one last largest count and incremented save. — Chandra Kant Paliwal, Feb 21 '18 at 14:35
Probably is because of the upsert, can you please try creating the document if not exists and than update it? — Naramsim, Feb 22 '18 at 10:46
Possible related/duplicate: https://stackoverflow.com/questions/26865357/default-value-not-set-while-using-update-with-upsert-as-true — Naramsim, Feb 22 '18 at 10:47

score 2 · Answer 1 · answered Feb 22 '18 at 10:49

2

Probably this is why it happens: https://github.com/Automattic/mongoose/issues/3617#issuecomment-160296684

Use the setDefaultsOnInsert option. Or just manually use {$inc: {n:1}, $setOnInsert: {n:776} }

answered Feb 22 '18 at 10:49

Naramsim

8,059
6
35
43

Someone Said me mongodb is Document-oriented database and is not good for auto increments, Then Can I make a project without auto increments number? – Saeed Heidarizarei Feb 22 '18 at 17:42
It completely depends on the project – Naramsim Feb 26 '18 at 08:00
When we need auto increments numbers? – Saeed Heidarizarei Feb 26 '18 at 11:40
Yep, so use the above. If your app is heavy switch to another DB like Redis – Naramsim Feb 26 '18 at 12:51

score 0 · Answer 2 · answered Jun 15 '16 at 10:23

0

You can install mongoose-auto-increment.

yourSchema.plugin(autoIncrement.plugin, {
    model: 'model',
    field: 'field',
    startAt: 5000,
    incrementBy: 1
});

It's easy to install and use.

answered Jun 15 '16 at 10:23

vartika

494
2
12

score 0 · Answer 3 · edited Oct 01 '21 at 14:43

I was also facing same issue so i came up with this solution.

var mongoose = require("mongoose");

// define the schema for our model
var caseStudySchema = mongoose.Schema({
 caseStudyNo: {
  type:Number,
  default:5000
 },
 firstName: String,
 lastName: String,
});

caseStudySchema.pre('save', function(next) {

var doc = this;

//Retrieve last value of caseStudyNo
CaseStudy.findOne({},{},{sort: { 'caseStudyNo' :-1}}, function(error, counter)   {
//if documents are present in collection then it will increment caseStudyNo 
// else it will create a new documents with default values 
 
    if(counter){
      counter.caseStudyNo++;
      doc.caseStudyNo=counter.caseStudyNo;
    }
    next();
 });
});
// module.exports allows us to pass this to other files when it is called
// create the model for users and expose it to our app
const CaseStudy = mongoose.model('CaseStudy', caseStudySchema);
module.exports = CaseStudy;

Auto Increment Sequence Mongoose

3 Answers3