Mongoose Document Model.init() API

The Model.init() method of Mongoose API is responsible for building indexes. Although, Mongoose calls this function automatically when a model is created using mongoose.model() or connection.model().

Syntax:

Model_Name.init()

Parameters: The Model.init() method accepts one parameters:

• callback: It is a callback function that will run once execution is completed.

Return Value: The Model.init() function returns a promise.

Setting up Node.js application:

Step 1: Create a Node.js application using the following command:

npm init

Step 2: After creating the NodeJS application, Install the required module using the following command:

npm install mongoose

Project Structure: The project structure will look like this:

Database Structure: The database structure will look like this, the following documents are present in the collection.

Example 1: In this example, We have established a database connection using mongoose and defined model over userSchema, having two columns or fields “name” and “age”. In the end, we are using the init() method on the User model which will build the indexes for the model.

• app.js: Write down the below code in the app.js file:

// Require mongoose module
const mongoose = require('mongoose');

// Set Up the Database connection
mongoose.connect(
    'mongodb://localhost:27017/geeksforgeeks', {
    useNewUrlParser: true,
    useUnifiedTopology: true
})

const userSchema = new mongoose.Schema(
    { name: String, age: Number }
)

// Defining userSchema model
const User = mongoose.model('User', userSchema);

User.init().then(function(Event){
    console.log('Indexes Builded')
})