have_posts and orderby

Hi,
I’m trying to modify the archive.php file because I need to order the results from the query in a datetime way…

The Loop start with the typical:

<?php
while ( $the_query->have_posts() ) : $the_query->the_post();
?>

So I read around and people in previous posts suggested to use this before:

<?php query_posts('meta_key=data&orderby=meta_key&order=DESC');?>

But doesn’t work.

The table fields where he’s grabbing data with mysql is something like this:

INSERT INTOwp_postmeta(meta_id,post_id,meta_key,meta_value`) VALUES
(86074, 15099, ‘orario_corsi’, ‘15.00 – 18.00’),
(86075, 15099, ‘tipo_corso’, ‘Demo gratuita’),
(86076, 15099, ‘punti_vendita’, ‘a:1:{i:0;s:8:”Collegno”;}’),
(86077, 15099, ‘data’, ‘20130930’),
(86078, 15099, ‘prezzo_corso’, ”),
(86079, 15099, ‘_wp_page_template’, ‘default’),
(86080, 15099, ‘_yoast_wpseo_linkdex’, ’43’),
(86081, 15099, ‘_edit_lock’, ‘1378307873:1’),
(86082, 15099, ‘_thumbnail_id’, ‘14271’),
(86083, 15099, ‘_edit_last’, ‘1’),
(86084, 15099, ‘novità’, ‘0’),
(86085, 15099, ‘_novità’, ‘field_51a49e93b7613’),
(86086, 15099, ‘_punti_vendita’, ‘field_51891cfde30f4’),
(86087, 15099, ‘_data’, ‘field_518cbb149ef68’),
(86088, 15099, ‘_orario_corsi’, ‘field_521f68b550fbd’),
(86089, 15099, ‘_prezzo_corso’, ‘field_521f6a53c2ec6’),
(86090, 15099, ‘_tipo_corso’, ‘field_521f68fbb78a5’),
(86091, 15099, ‘gallery’, ‘0’),
(86092, 15099, ‘_gallery’, ‘field_517b9480b9e6d’),
(86093, 15099, ‘documenti’, ‘0’),
(86094, 15099, ‘_documenti’, ‘field_517b94ece23db’),
(86095, 15099, ‘_expiration-date’, ‘1380578400’),
(86096, 15099, ‘_expiration-date-options’, ‘a:2:{s:10:”expireType”;s:5:”draft”;s:2:”id”;i:15099;}’),
(86097, 15099, ‘_expiration-date-status’, ‘saved’),
(86098, 15099, ‘_yoast_wpseo_focuskw’, ‘medium materici’),
(86099, 15099, ‘_yoast_wpseo_title’, ‘Rilievi d”effetto – Viridea’),
(86100, 15099, ‘_yoast_wpseo_metadesc’, ‘Usiamo i medium materici per effetti tridimensionali.’),
(86101, 15099, ‘_yoast_wpseo_meta-robots-noindex’, ‘0’),
(86102, 15099, ‘_yoast_wpseo_meta-robots-nofollow’, ‘0’),
(86103, 15099, ‘_yoast_wpseo_meta-robots-adv’, ‘none’),
(86104, 15099, ‘_yoast_wpseo_sitemap-include’, ‘-‘),
(86105, 15099, ‘_yoast_wpseo_sitemap-prio’, ‘-‘),
(86106, 15099, ‘_yoast_wpseo_sitemap-html-include’, ‘-‘),
(86107, 15099, ‘_yoast_wpseo_canonical’, ”),
(86108, 15099, ‘_yoast_wpseo_redirect’, ”),
(86109, 15099, ‘_yoast_wpseo_opengraph-description’, ”),
(86110, 15099, ‘_yoast_wpseo_google-plus-description’, ”),
(86111, 15099, ‘_dp_original’, ‘14137’),`

Need help ??

Thanks!