How to communicate with database in Node.js | REST API | PostgreSQL

In this article, we will discuss how to communicate with a database in Node.js using a REST API and PostgreSQL.

Node.js

Node.js is a popular runtime environment that allows developers to build scalable network applications. It uses JavaScript, which makes it easy for front-end developers to transition to server-side development.

REST API

REST API stands for Representational State Transfer Application Programming Interface. It is an architectural style for designing networked applications. A RESTful API uses HTTP requests to perform CRUD (Create, Read, Update, Delete) operations on resources. It is stateless, meaning it doesn’t store any client context on the server between requests.

PostgreSQL

PostgreSQL is a powerful, open-source object-relational database system. It is known for its reliability, data integrity, and robust feature set.

Communicating with Database in Node.js

To communicate with a PostgreSQL database in Node.js, we can use the `pg` package, which is the official PostgreSQL client for Node.js. First, install the package using npm:

        
            npm install pg
        
    

Next, we can create a database connection and perform CRUD operations using the `pg` package. Here’s an example of how to connect to a PostgreSQL database in Node.js:

        
            const { Client } = require('pg');

            const client = new Client({
                user: 'your_username',
                host: 'localhost',
                database: 'your_database_name',
                password: 'your_password',
                port: 5432,
            });

            client.connect();

            // Perform CRUD operations here

            client.end();
        
    

Using REST API with Node.js and PostgreSQL

We can also create a RESTful API in Node.js to communicate with a PostgreSQL database. We can use frameworks such as Express.js to handle HTTP requests and responses, and the `pg` package to interact with the database.

Here’s an example of how to create a simple REST API to perform CRUD operations on a PostgreSQL database in Node.js:

        
            const express = require('express');
            const { Client } = require('pg');

            const app = express();
            const client = new Client({
                user: 'your_username',
                host: 'localhost',
                database: 'your_database_name',
                password: 'your_password',
                port: 5432,
            });

            client.connect();

            app.get('/users', (req, res) => {
                client.query('SELECT * FROM users', (err, result) => {
                    if (err) {
                        res.status(400).send(err);
                    } else {
                        res.status(200).json(result.rows);
                    }
                });
            });

            // Add routes for other CRUD operations

            app.listen(3000, () => {
                console.log('Server is running on port 3000');
            });
        
    

Conclusion

In this article, we have learned how to communicate with a PostgreSQL database in Node.js using a REST API. By using the `pg` package and frameworks like Express.js, we can easily create scalable and efficient applications that interact with a database. With the knowledge gained from this article, you should be able to build your own REST API and perform CRUD operations on a PostgreSQL database using Node.js.