global $wpdb, $post, $table_prefix;

if ($post->ID) {
$retval = ‘<ul>’;
// Get tags
$tags = wp_get_post_tags($post->ID);
$tagsarray = array();
foreach ($tags as $tag) {
$tagsarray[] = $tag->term_id;
}
$tagslist = implode(‘,’, $tagsarray);

// Do the query
$q = "SELECT p.*, count(tr.object_id) as count
FROM $wpdb->term_taxonomy AS tt, $wpdb->term_relationships AS tr, $wpdb->posts AS p WHERE tt.taxonomy =’post_tag’ AND tt.term_taxonomy_id = tr.term_taxonomy_id AND tr.object_id = p.ID AND tt.term_id IN ($tagslist) AND p.ID != $post->ID
AND p.post_status = ‘publish’
AND p.post_date_gmt < NOW()
GROUP BY tr.object_id
ORDER BY count DESC, p.post_date_gmt DESC
LIMIT $limit;";

$related = $wpdb->get_results($q);
if ( $related ) {
foreach($related as $r) {
$retval .= ‘
<li><a title="’.wptexturize($r->post_title).’" href="’.get_permalink($r->ID).’">’.wptexturize($r->post_title).’</a></li>
‘;
}
} else {
$retval .= ‘
<li>No related posts found</li>
‘;
}
$retval .= ‘</ul>
‘;
return $retval;
}
return;
}
add_shortcode(‘related_posts’, ‘related_posts_shortcode’);