Mongoose is an ODM (Object Data Modeling) library built on top of the MongoDB driver. It allows for concise interaction with MongoDB and simple object modeling within a NodeJS environment.
Before starting, it is recommended that you:
Set up a non-root user with sudo privileges. Follow Vultr's best practice guide here.
Verify your server is up to date. Follow Vultr's best practice guide here.
Make sure build-essential is installed. If not, install using:
$ sudo apt install build-essential
Install MongoDB.
$ sudo apt install mongodb
Verify it was installed properly. Look for "active (running)" in the output.
$ sudo systemctl status mongodb
Active: active (running)
Add the latest stable NodeJS repository.
$ curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -
Install NodeJS.
$ sudo apt install nodejs
Verify NodeJS and NPM are installed properly.
$ node -v && npm -v
v12.x.x
6.x.x
Create the project root directory.
$ cd ~
$ mkdir mongooseProject && cd mongooseProject
Initialize a NodeJS development environment to automatically generate a package.json:
$ npm init
Answer the short questions to fit your project. For example, if you press return at each question to accept the defaults, the npm init process responds:
About to write to /root/mongooseProject/package.json:
{
"name": "mongooseproject",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"author": "",
"license": "ISC"
}
Install the required packages using npm in the project root directory:
$ npm install --save mongoose
Create a folder called Models in the root directory of the project and cd into it:
$ cd ~/mongooseProject
$ mkdir Models && cd Models
Create connectDB.js. This file will contain the connection logic needed for the MongoDB server.
$ nano connectDB.js
Paste the following into connectDB.js.
const mongoose = require('mongoose'); // Import mongoose library
module.exports = function(uri) {
mongoose.connect(uri, { //attempt to connect to database
useNewUrlParser: true, // Recommended, insures support for future MongoDB drivers
useUnifiedTopology: true // Recommended, uses new MongoDB topology engine
}).catch(error => console.log(error)) // Error handling
mongoose.connection.on('connected', function () { // On connection
console.log('Successful connection with database: ' + uri); // Callback for successful connection
});
}
Create Users.js. This file will contain the model for the database collection Users.
$ nano Users.js
Paste the following into Users.js. This defines a basic schema for users.
const mongoose = require("mongoose"); // Import mongoose library
const Schema = mongoose.Schema // Define Schema method
// Schema
var UsersSchema = new Schema({ // Create Schema
name: String, // Name of user
age: Number, // Age of user
role: String // Role of user
})
// Model
var Users = mongoose.model("Users", UsersSchema) // Create collection model from schema
module.exports = Users // export model
Create insertUser.js in the root directory of the project.
$ cd ~/mongooseProject
$ nano insertUser.js
Paste the following into insertUser.js file. This file inserts documents into the Users collection.
//Library
const mongoose = require("mongoose")
// Database connection
const connectDB = require("./Models/connectDB")
var database = "mongoose" // Database name
// Models
const Users = require("./Models/Users")
// Connect to database
connectDB("mongodb://localhost:27017/"+database)
var insertedUser = new Users({ // Create new document
name: "John Doe",
age: 18,
role: "Example User"
})
insertedUser.save(err => { // save document inside Users collection
if(err) throw err // error handling
console.log("Document inserted!")
mongoose.disconnect() // disconnect connection from database once document is saved
})
Run insertUser.js.
$ node insertUser.js
Successful connection with database: mongodb://localhost:27017/mongoose
Document inserted!
Create readUsers.js in the root directory of the project.
$ cd ~/mongooseProject
$ nano readUsers.js
Paste the following into readUsers.js. This file reads documents in the Users collection.
//Library
const mongoose = require("mongoose")
// Database connection
const connectDB = require("./Models/connectDB")
var database = "mongoose" // Database name
// Models
const Users = require("./Models/Users")
// Connect to database
connectDB("mongodb://localhost:27017/"+database)
Users.find({}, (err, users)=>{ //find and return all documents inside Users collection
if(err) throw err // error handling
console.log(users)
mongoose.disconnect()
})
Run readUsers.js. The output is an array of objects.
$ node readUsers.js
Successful connection with database: mongodb://localhost:27017/mongoose
[ { _id: ************************,
name: 'John Doe',
age: 18,
role: 'Example User',
__v: 0 } ]
You have set up Mongoose to work with MongoDB. For more information, please see the Mongoose API documentation