mongoose-auto-increment

mongoose-auto-increment

Mongoose plugin that auto-increments any ID field on your schema every time a document is saved.

Getting Started

npm install mongoose-auto-increment

Once you have the plugin installed it is very simple to use. Just get reference to it, initialize it by passing in your mongoose connection and pass autoIncrement.plugin to the plugin() function on your schema.

Note: You only need to initialize MAI once.

var mongoose = require('mongoose'),
    autoIncrement = require('mongoose-auto-increment');

var connection = mongoose.createConnection("mongodb://localhost/myDatabase");

autoIncrement.initialize(connection);

var bookSchema = new mongoose.Schema({
    author: { type: Schema.Types.ObjectId, ref: 'Author' },
    title: String,
    genre: String,
    publishDate: Date
});

bookSchema.plugin(autoIncrement.plugin, 'Book');
var Book = connection.model('Book', bookSchema);

That's it. Now you can create book entities at will and the _id field will automatically increment with each new document.

Want a field other than _id?

bookSchema.plugin(autoIncrement.plugin, { model: 'Book', field: 'bookId' });

Want that field to start at a different number than zero or increment by more than one?

bookSchema.plugin(autoIncrement.plugin, {
    model: 'Book',
    field: 'bookId',
    startAt: 100,
    incrementBy: 100
});

Your first book document would have a bookId equal to 100. Your second book document would have a bookId equal to 200, and so on.

Want your field to increment every time you update it too?

bookSchema.plugin(autoIncrement.plugin, {
    model: 'Book',
    field: 'bookId',
    startAt: 100,
    incrementBy: 100
});

Want to know the next number coming up?

var Book = connection.model('Book', bookSchema);
Book.nextCount(function(err, count) {

    // count === 0 -> true

    var book = new Book();
    book.save(function(err) {

        // book._id === 0 -> true

        book.nextCount(function(err, count) {

            // count === 1 -> true

        });
    });
});

nextCount is both a static method on the model (`Book.nextCount(...)`) and an instance method on the document (`book.nextCount(...)`).