Essential PHP Programming: Forms, Databases, and Sessions

PHP Form Validation

To create a PHP form and perform server-side validation for user input such as name, email, and password:

<?php
$name = $email = $password = "";
$nameErr = $emailErr = $passwordErr = "";

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // Name Validation
    if (empty($_POST["name"])) { $nameErr = "Name is required"; } else { $name = $_POST["name"]; }
    // Email Validation
    if (empty($_POST["email"])) { $emailErr = "Email is required"; } else { $email = $_POST["email"];
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { $emailErr = "Invalid email format"; } 
    }
    // Password Validation
    if (empty($_POST["password"])) { $passwordErr = "Password is required"; } else { $password = $_POST["password"];
        if (strlen($password) < 6) { $passwordErr = "Password must be at least 6 characters"; } 
    }
}
?>

Name:

Email: <?php echo $emailErr; ?>

Password:

MySQL Database: Inserting Multiple Records

To insert multiple records into a MySQL database table using PHP and SQL INSERT query.

Assumption

• Database name: csit_db
• Table name: students
• Fields: id, name, email

CREATE DATABASE csit_db;
USE csit_db;
CREATE TABLE students (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(50), email VARCHAR(50));

Inheritance in PHP

Types of Inheritance in PHP:

• Single Inheritance
• Multilevel Inheritance
• Hierarchical Inheritance

PHP Cookies

A cookie is a small piece of data stored on the client's browser by a web server to maintain user information and session state.

Features of Cookies

• Stored on client browser
• Small size (around 4KB)
• Used for session tracking
• Automatically sent with HTTP request

PHP Session Handling

Sessions allow you to store user information across multiple pages.

• Start Session: session_start();
• Destroy Session: session_destroy();

Concatenating Strings with Functions

function joinStrings($str1, $str2) {
    return $str1 . " " . $str2;
}
$result = joinStrings("ramayan", "torpey");
echo "Concatenated String: " . $result;