$db = JFactory::getDbo();
$query = $db->getQuery(true);
$query->select($db->quoteName(array('denominazione', 'indirizzo', 'cap', 'citta')));
$query->from($db->quoteName('#__provincia'));
$query->where($db->quoteName('id') . ' = '.$provincia_id );
$db->setQuery($query);
$columns = $db->loadRow();