$DbConnect = mysqli_connect("localhost","root","s");
mysqli_set_charset($DbConnect, "UTF8");
if(mysqli_connect_errno()){
echo "Hatalı HatalıHatalıHatalıHatalıHatalıHatalıHatalı";
echo "Hata sebebiniz: " . mysqli_connect_error() . "<br/>";
}else{
echo "Başarılı";
};
    mysqli_close($DbConnect);

    $host_name = "localhost";
    $database = "dbname";
    $username = "dbusername";
    $password = "dbpassword";
    try{
        $db = new PDO('mysql:host='.$host_name.';charset=utf8;dbname='.$database, $username, $password);
    }catch(PDOException $e){
        print "Hata " . $e->getMessage() . "<br/>";
        die();
    }
    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);