Connecting to Database

Definition:

To work with databases in PHP, we need to connect to MySQL.
MySQLi (MySQL Improved) is an extension in PHP used to:

• Establish a connection with a MySQL database.
• Send SQL queries and get results.
• Work with procedural style or object-oriented style.

Procedural Connection:

<?php
$servername = "localhost";   // Server name where MySQL is running
$username   = "root";        // Default MySQL username in local
$password   = "";            // Password (empty for XAMPP/WAMP by default)
$dbname     = "mydatabase";  // Database name

// Step 1: Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);

// Step 2: Check connection
if(!$conn){
    die("Connection failed: " . mysqli_connect_error());
}

echo "Connected successfully";
?>

Explanation:

• mysqli_connect() → establishes connection to MySQL.
• If the connection fails, mysqli_connect_error() shows the error.
• die() stops the script execution and shows the error.
• If successful, it prints "Connected successfully".

Object-Oriented Connection:

<?php
$conn = new mysqli("localhost", "root", "", "mydatabase");

if($conn->connect_error){
    die("Connection failed: " . $conn->connect_error);
}

echo "Connected successfully";
?>

Explanation:

• $conn = new mysqli(...) → creates a new object for the connection.
• $conn->connect_error → checks if there is any connection error.
• This style is preferred in modern PHP applications.