Connecting

The MongoClient connection method returns a Promise if no callback is passed to it. Below is an example using the async/await commands.

const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');
(async function() {
 // Connection URL
 const url = 'mongodb://localhost:27017/myproject';
 // Database Name
 const dbName = 'myproject';
 let client;
 try {
 // Use connect method to connect to the Server
 client = await MongoClient.connect(url);
 const db = client.db(dbName);
 } catch (err) {
 console.log(err.stack);
 }
 if (client) {
 client.close();
 }
})();

The MongoClient.connect function returns a Promise that we then execute using the await keyword inside of an async function. If an error happens during the MongoClient.connect the error is caught by the try/catch and can be handled as if it were a normal Javascript error.