PHP Lab 1: User Registration & Login

Lab Objectives

Understand web app workflow: Input → Processing → Output → Storage
Create PHP scripts to handle forms and user input
Connect PHP to MySQL database
Implement basic security practices: password hashing and input validation
Manage user sessions for login and logout

Prerequisites

XAMPP / WAMP / LAMP installed
Basic HTML & PHP knowledge
Browser (Chrome / Firefox)

Step 1: Database Setup

Create database and table in MySQL:


CREATE DATABASE php_lab;
USE php_lab;

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) UNIQUE NOT NULL,
    password VARCHAR(255) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

Step 2: PHP File Structure

config.php (Database connection)
register.php (User registration)
login.php (Login page)
dashboard.php (Welcome dashboard)
logout.php (Logout)
style.css (Optional styling)

Step 3: PHP Scripts

See lab manual or starter code for:

config.php
register.php
login.php
dashboard.php
logout.php

Step 4: Exercises

Set up XAMPP / LAMP on your machine
Create the database and table using MySQL
Create PHP files according to the folder structure
Test registration → login → dashboard → logout
Try registering a duplicate username and observe the error
Try logging in with incorrect credentials and observe the output
Check database to see that passwords are hashed
Bonus: add a "last login" timestamp

Questions

Explain the difference between Input, Processing, Output, and Storage in this lab.
Why do we use password_hash() instead of storing passwords directly?
How does a prepared statement help prevent SQL injection?
What is the purpose of session_start() in the login system?
What happens if a user tries to login with a wrong password multiple times? How could you improve security?
Explain what would happen if we didn’t validate input in registration.

Expected Learning Outcomes

Understand how web forms interact with PHP and databases
Implement secure user authentication
Understand session management for logged-in users
Gain confidence in basic PHP web application development

Note: Save all your files under the folder first_php_lab and run them locally. Do not upload to a public server as passwords are sensitive data.