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.

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.

• javascript
• node.js
• mongodb
• mongoose

• you can install this module mongoose-auto-increment – morels Commented Jun 15, 2016 at 10:00
• you can create before to get find one last largest count and incremented save. – Chandra Kant Paliwal Commented Feb 21, 2018 at 14:35
• Probably is because of the upsert, can you please try creating the document if not exists and than update it? – Naramsim Commented Feb 22, 2018 at 10:46
• Possible related/duplicate: stackoverflow./questions/26865357/… – Naramsim Commented Feb 22, 2018 at 10:47

3 Answers 3

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

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

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.

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;