aplique no que me comentas, quite el while y quedo mi consulta si.. pero no me funciona no me imprime nada :(
Código PHP:
$sql = "SELECT DISTINCT helper, driver FROM _ordertrucking
WHERE (CAST(CONCAT(anio, '-', mes, '-', dia) AS DATE) BETWEEN CAST('$from' AS DATE) AND CAST('$to' AS DATE))
AND dispatched = 'NO'
AND route = '$route'";
$row = mysql_fetch_array($sql);
$helper = $row['helper'];
$driver = $row['driver'];
echo $helper.", ".$driver;