Mongoose plugin that auto-increments any ID field on your schema every time a document is saved.
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.
bookSchema.plugin(autoIncrement.plugin, { model: 'Book', field: 'bookId' });
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.
bookSchema.plugin(autoIncrement.plugin, {
model: 'Book',
field: 'bookId',
startAt: 100,
incrementBy: 100
});
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(...)
).