consulta sql

$listquery = 'SELECT `id`,`username`, `password`, `authMethod`'
                . ' FROM `tableName` WHERE 1;    

/* object */
$db =& JFactory::getDBO();
$db->setQuery( $objquery );
$db->loadObject();

/* object list */
$db =& JFactory::getDBO();
$db->setQuery( $listquery );
$db->loadObjectList();