PHP MySQL Connection

Using MySQLi (Object-Oriented)

$conn = new mysqli("localhost", "username", "password", "database");

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

Using PDO

try {
    $pdo = new PDO("mysql:host=localhost;dbname=database", "username", "password");
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    die("Connection failed: " . $e->getMessage());
}

Best Practices

• Always use prepared statements for SQL queries
• Close connections when done: $conn->close() or $pdo = null
• Store credentials in environment variables, not in code

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