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'},{$inc: { seq: 1}},{"upsert": true,"new": true }, function(error, counter) {
if(error)
return next(error);
doc.caseStudyNo = counter.seq;
next();
});
});
// module.exports allows us to pass this to other files when it is called
// create the model for users and expose it to our app
module.exports = mongoose.model('CaseStudy', caseStudySchema);
I can't figure out why its starting form 1 when I have set the default as 5000. The sequence should be 5001, 5002, 5003 and so on. Any help will be greatly appreciated.
Probably this is why it happens: https://github.com/Automattic/mongoose/issues/3617#issuecomment-160296684
Use the
setDefaultsOnInsert
option. Or just manually use{$inc: {n:1}, $setOnInsert: {n:776} }
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.
This is such a common need that it might be worthwhile using an existing module. I played around with a few, but this was the easiest to get to work with my project. https://www.npmjs.com/package/mongoose-sequence . Remember if you want to repurpose the _id
field, you must declare it as a Number
type in your schema as per the docs.
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 increament 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;
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