Verifying syntax executed correctly

["Ron Piggott (PHP)" <ron.php@xxxxxxxxxxxxxxxxxx>]

If I give this command through PHP to mySQL

mysql_connect(localhost,$username,$password);
@mysql_select_db($database) or die( "Unable to select database");
$query = "UPDATE `table` SET `last_activity_field` = '$current_date'
WHERE `reference` = '$account_reference' LIMIT 1;";
mysql_query($query);
mysql_close();

is there a way to know if it executed successfully?

Ron