PDO - PHP Data Objects

    function db(): PDO
    {
        static $pdo;

        if (!$pdo) {
            return new PDO(
                sprintf("mysql:host=%s;dbname=%s;charset=UTF8", DB_HOST, DB_NAME),
                DB_USER,
                DB_PASSWORD,
                [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]
            );
        }
    
        return $pdo;
    }