@ed3ath/mongoose-auto-increment
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This plugin allows you to auto-increment any field on any mongoose schema that you wish.
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# mongoose-auto-increment
[](https://travis-ci.org/codetunnel/mongoose-auto-increment)
[](https://gemnasium.com/codetunnel/mongoose-auto-increment)
[](http://badge.fury.io/js/mongoose-auto-increment)
> Mongoose plugin that auto-increments any ID field on your schema every time a document is saved.
---
> This is the module used by [mongoose-simpledb](https://github.com/codetunnel/mongoose-simpledb) to increment Number IDs. You are perfectly able to use this module by itself if you would like. However, if you're looking to make your life easier when using [mongoose](http://mongoosejs.com/) then I highly recommend you check out simpledb. It's a small wrapper around mongoose but it makes it extremely easy to deal with your models and draws a clear path for how to use mongoose in your application.
## 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.
````js
var mongoose = require('mongoose'),
Schema = mongoose.Schema,
autoIncrement = require('mongoose-auto-increment');
var connection = mongoose.createConnection("mongodb://localhost/myDatabase");
autoIncrement.initialize(connection);
var bookSchema = new 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 they will have an `_id` field added of type `Number` and will automatically increment with each new document. Even declaring references is easy, just remember to change the reference property's type to `Number` instead of `ObjectId` if the referenced model is also using the plugin.
````js
var authorSchema = new mongoose.Schema({
name: String
});
var bookSchema = new Schema({
author: { type: Number, ref: 'Author' },
title: String,
genre: String,
publishDate: Date
});
bookSchema.plugin(autoIncrement.plugin, 'Book');
authorSchema.plugin(autoIncrement.plugin, 'Author');
````
### Want a field other than `_id`?
````js
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?
````js
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 to know the next number coming up?
````js
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(...)`).
### Want to reset counter back to the start value?
````js
bookSchema.plugin(autoIncrement.plugin, {
model: 'Book',
field: 'bookId',
startAt: 100
});
var Book = connection.model('Book', bookSchema),
book = new Book();
book.save(function (err) {
// book._id === 100 -> true
book.nextCount(function(err, count) {
// count === 101 -> true
book.resetCount(function(err, nextCount) {
// nextCount === 100 -> true
});
});
});
````