Is there a way to have an integer autoincrement field in Mongo Db as part of a document/table different from the standard id?

Question

We'd love to have an integer autoincrement field within a Mongo Db document / "table", possibly being different from the autogenerated and unique _id index.

The purpose is to provide the users with a unique readable number, auto-incrementing itself, to be used as a reference for the logical entity associated with the database table we are using. The users will refer to that number for example to identify a printed document associated to that entity.

The expected behavior would be to have that number automatically incremented within the database table itself, exactly like it happens in different kinds of databases.

We have implemented our project with the combo: Vue JS - Node - Mongo db. The aim would be to avoid using some JS "trick" to physically increment the number, while having this action done directly in the model of the document.

We couldn't find anything like that in the official documentation, could someone please help us with this? Thanks so much in advance.

venkatesh pogartha · Answer 1 · 2021-01-05T09:34:29.730

2

MongoDB does not have an auto increment functionality(In built). Need to write extra logic to do that.

You could solve this by keeping track the 'id' in a separate collection called 'user_sequence' and store a custom function in MongoDB to get the next value.

Take a look at: https://docs.mongodb.com/manual/tutorial/store-javascript-function-on-server/

Create a query like:

db.users.insert({
    userid: sequenceNextValue("userid")
})

Step by step tutorial by MongoDB: https://docs.mongodb.com/v3.0/tutorial/create-an-auto-incrementing-field/

REF:- mongodb second id field with auto increment

WAY - 2

if you like to use Mongoose (node lib). Following code will help you

var CounterSchema = Schema({
    _id: {type: String, required: true},
    seq: { type: Number, default: 0 }
});
var counter = mongoose.model('counter', CounterSchema);

var entitySchema = mongoose.Schema({
    testvalue: {type: String}
});

entitySchema.pre('save', function(next) {
    var doc = this;
    counter.findByIdAndUpdate({_id: 'entityId'}, {$inc: { seq: 1} }, function(error, counter)   {
        if(error)
            return next(error);
        doc.testvalue = counter.seq;
        next();
    });
});

edited Jan 05 '21 at 09:34

answered Jan 05 '21 at 09:29

venkatesh pogartha

271
1
5

Thank you so much Venkatesh Pogartha, I'll certainly give it a try and come back to you. – frandro93 Jan 05 '21 at 10:12
Be aware, this approach may have a significant impact on the application performance. – Wernfried Domscheit Jan 05 '21 at 10:54
Thanks for the warning. Do you think there's a different approach to tackle this problem having less performance impact? – frandro93 Jan 05 '21 at 14:20
In my case $inc not worked because i used $inc inside $set :( await userSchema.updateOne({ _id: mongoose.Types.ObjectId(req.userId) }, { $set: { $inc: { myBalance: claimAmount } } }); – MUHAMMAD SHAHID RAFI C P Oct 15 '22 at 14:10

score 0 · Answer 2 · answered Oct 15 '22 at 14:15

In my case $inc not worked because i used $inc inside $set :(

for example

await userSchema.updateOne({ _id: mongoose.Types.ObjectId(req.userId) }, { $set: { $inc: { myBalance: -claimAmount } } });

instead of

await userSchema.updateOne({ _id: mongoose.Types.ObjectId(req.userId) }, { $inc: { myBalance: -claimAmount }});

Is there a way to have an integer autoincrement field in Mongo Db as part of a document/table different from the standard id?

2 Answers2