News Letter Registration Web App with MySQL and Express

Project Overview

This project is a user registration web application developed using Node.js, Express, and MySQL. It allows users to register by providing their email addresses, and the app stores this information in a MySQL database. The application uses SQL for managing the data interactions, including querying and updating the user data in the database.

Key Technologies

Node.js: The runtime environment for executing JavaScript on the server side.
Express: A web application framework for Node.js, used to set up the server and define routes.
MySQL: The relational database management system used to store user data.
EJS: Embedded JavaScript templating for rendering dynamic HTML content.
dotenv: Environment variable management for securely handling sensitive data.
body-parser: Middleware for parsing request bodies, specifically application/x-www-form-urlencoded for form data in this project.

Project Structure

The main structure includes:

Environment Configuration: Using .env to securely store database credentials.
Express Server Setup: Configured to listen on port 8080.
Static Files: Serving static files from the public directory.
MySQL Connection: Configuring a connection to the MySQL database.

SQL Usage

Database Setup

The MySQL database consists of a single table named users. Each record represents a user and includes fields for a unique user ID and an email address.

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    email VARCHAR(255) NOT NULL UNIQUE
);

SQL Queries

Counting Users The home route (/) displays the total number of registered users. To achieve this, a SELECT COUNT(*) query is used:

let q = "SELECT COUNT(*) AS count FROM users";
connection.query(q, function(err, results){
    if(err) throw err;
    let count = results[0].count;
    res.render("home", {count: count});
});

Registering a New User The /register route handles new user registrations. When a form is submitted, it executes an INSERT INTO query to add the user’s email to the users table:

let person = { email: req.body.email };
connection.query('INSERT INTO users SET ?', person, function(err, result) {
    if (err) throw err;
    res.redirect("/");
});

The SQL INSERT INTO statement is dynamically populated using the user-provided email, which is securely passed to prevent SQL injection.

Key Features

Environment Variables: Sensitive information like database credentials are stored in a .env file to ensure security.

Data Handling with SQL: This app uses SQL queries to retrieve and modify data, showcasing SQL’s integration with Node.js for effective data management.

Error Handling: Basic error handling is implemented to ensure the application fails gracefully in the event of a database error.

Running the Project

Clone the repository.
Install dependencies:

npm install

Set up a MySQL database and create the users table.

Configure environment variables in a .env file:

DB_HOST=your_host
DB_USER=your_user
DB_PASSWORD=your_password
DB_NAME=your_database

Start the server: node app.js
Open http://localhost:8080 in a browser to view the app.

Conclusion

This project demonstrates a straightforward use of SQL within a Node.js environment, allowing for data querying, insertion, and error handling with SQL and MySQL. It serves as a template for building similar applications that require user registration and database interaction with SQL.

CamilingJS/Join_Us_App

README