Connect Server

try {
$dsn = "mysql:host=$host;dbname=$db;charset=utf8mb4";
$opt = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];
$pdo = new PDO($dsn, $user, $pass, $opt);
} catch(PDOException $ex) {
    echo "Error occured during connecting to the server";
}

• dsn: Data Source Name
• pdo: PHP Data Object

alternative name of pdo

• dbh: DataBase Handling
• sth: Statement Handling

Fetch All

bindParam

$stmt = $pdo->prepare("SELECT password FROM users WHERE id = :username");
$stmt->bindParam(':username', $id);
$stmt->execute();
if ($stmt->rowCount() == 0) { // When Nothing is found
header('Location: ./index.php');
exit();
}