Welcome back to our Node.js blog series! In this part, we’ll explore two important aspects of Node.js development: interacting with databases and building web applications using Express.js. These topics are essential for creating dynamic, data-driven web applications. Let’s get started!

1. Interacting with Databases: Node.js provides several modules and libraries for interacting with databases, making it easy to store and retrieve data from various database systems. One popular choice is MongoDB, a NoSQL database, which we’ll use as an example. To interact with MongoDB in Node.js, we can use the MongoDB Node.js driver or an Object Data Modeling (ODM) library like Mongoose.

To begin, you need to install the required dependencies. Open your project directory in the terminal and run the following command:

npm install mongodb mongoose

Once the installation is complete, you can establish a connection to your MongoDB database and perform operations such as inserting, updating, querying, and deleting data. Here’s a simple example using Mongoose:

const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true })
  .then(() => {
    console.log('Connected to MongoDB');
    // Perform database operations here
  })
  .catch((error) => {
    console.error('Error connecting to MongoDB:', error);
  });

In the above code, we connect to a MongoDB database running locally. Once the connection is established, you can perform CRUD (Create, Read, Update, Delete) operations using Mongoose models and schemas.

Remember to refer to the documentation of your chosen database system or library for specific usage instructions and additional features.

2. Building Web Applications with Express.js: Express.js is a popular web framework for Node.js that simplifies the process of building web applications and APIs. It provides a robust set of features for routing, handling requests and responses, and integrating middleware.

To use Express.js, you first need to install it. Run the following command in your project directory:

npm install express

Once Express.js is installed, you can create an Express application and start defining routes and handling requests. Here’s a basic example:

const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.send('Hello, Express!');
});

app.listen(3000, () => {
  console.log('Express server started on port 3000');
});

In the above code, we create an Express application, define a route for the root URL (“/”), and send a response with the message “Hello, Express!” when the route is accessed. The server listens on port 3000.

Express.js offers powerful features like middleware, routing, template engines, error handling, and more. It allows you to build robust web applications and APIs efficiently.

Conclusion: In this blog post, we explored two crucial aspects of Node.js development: interacting with databases and building web applications with Express.js. We learned how to establish a connection to a MongoDB database using Mongoose and perform database operations. Additionally, we saw how to create a basic Express.js application and define routes to handle requests and send responses.

By mastering these concepts, you can build dynamic web applications, handle data effectively, and provide seamless user experiences. In the next part of our Node.js blog series, we will dive into advanced topics such as authentication, session management, and deploying Node.js applications. Stay tuned for more exciting content as we continue our journey with Node.js!

Technology illustrations by Storyset