Custom field query, SQL, and wrong author

Hello,

Our site publishes weekly issues. Each issue has a number and all our articles have a custom field where we indicate the number of the issue.

On every page of the site, in a side bar, a custom field query displays the summary : a list of all the articles of a given issue, and just below the title, the author of the article.

Here is the code I use :

<?php global $wpdb; global $post;

$sommaire = "
SELECT wposts.*
FROM $wpdb->posts wposts, $wpdb->postmeta wpostmeta
   WHERE wposts.ID = wpostmeta.post_id
   AND wpostmeta.meta_key = 'numero'
   AND wpostmeta.meta_value = '192'
   AND wposts.post_status = 'publish'
   AND wposts.post_type = 'post'
   ORDER BY wposts.post_date DESC
 ";
// List the posts
	$thelist = $wpdb->get_results($sommaire, OBJECT);
foreach ($thelist as $post): ?>

<a href="<?php the_permalink(); ?>"><?php the_title();?></a>

<?php $author = get_the_author();echo $author; ?>

<?php endforeach; ?>

The query works fine but I have a big problem with the authors : on single pages, my code is only able to retrieve the author of the article of the very page I’m on, NOT the various authors of the summary.

As a result, in my sidebar, all the listed articles have the same wrong author !

What am I doing wrong ? The SQL query retrieves the title all right, the permalink all right. Why not the auhor ?

Note : I have tried with php the_author() instead of get_the_author(). The result is the same