Connect Node Express and Mongodb

 In the root directory:

mkdir backend

cd backend

then type: npm init -y

npm install express cors mongodb dotenv

npm install -g nodemon

write the following line in package.json after "main":"index.js" :

"type":"module",

Now, create server.js file inside backend folder.

Write the following code in server.js file:

// starts here

import express from "express";

import cors from "cors"

import restaurants from "./api/restaurants.route.js"

const app = express();

app.use(cors());

app.use(express.json());

app.use("/api/v1/restaurants", restaurants);

app.use("*",(req,res) => res.status(404).json({error: "Not found!"}) );

export default app;

// ends here

create .env file and write:

RESTREVIEWS_DB_URI=mongodb+srv://ipritpritam:ipritpritam@cluster0.twcdr.mongodb.net/sample_restaurants?retryWrites=true&w=majority

RESTREVIEWS_NS=sample_restaurants

PORT=5000

then, create index.js in the backend folder and write the following:

// starts here

import app from "./server.js"

import mongodb from "mongodb"

import dotenv from "dotenv"

dotenv.config()

const MongoClient = mongodb.MongoClient

const port = process.env.PORT ||  8000

MongoClient.connect(

    process.env.RESTREVIEWS_DB_URI,

    {

        // poolSize: 50,// 50 people can connect at a time

        // wtimeout: 2500,

        maxPoolSize:50,

        wtimeoutMS:2500,

        // useNewUrlParse: true

    }

)

.catch(err => {

    console.error(err.stack);

    process.exit(1);

})

.then(async client => {

    app.listen(port, () => {

        console.log(`listening on port ${port}`);

    });

});

// ends here

create a api folder inside backend folder then, create a file called 'restaurants.route.js'.

Inside restaurants.route.js write the following lines of code:

// starts here

import express from "express"

const router = express.Router();

router.route("/").get((req,res) => res.send("Hello World"));

export default router;

// ends here

Then run: nodemon server

and see the url: http://localhost:5000/api/v1/restaurants