Displaying Posts Using a Custom Select Query

Hey there, I’m using this code to display only the last article that has not the custom field «featured» empty.
Yeah, I’m trying to code something to make a featured section.

<?php
global $wpdb;
global $post;
$querystr = "
SELECT wposts.*
FROM $wpdb->posts wposts
	LEFT JOIN $wpdb->postmeta wpostmeta ON wposts.ID = wpostmeta.post_id
	LEFT JOIN $wpdb->term_relationships ON (wposts.ID = $wpdb->term_relationships.object_id)
	LEFT JOIN $wpdb->term_taxonomy ON ($wpdb->term_relationships.term_taxonomy_id = $wpdb->term_taxonomy.term_taxonomy_id)
WHERE wpostmeta.meta_key != ''
ORDER BY wpostmeta.meta_value ASC
LIMIT 1";
echo $querystr[id];

?>

I think that there’s something wrong on the echo part, cause im not getting any sintax error. Could you give me a hand?
Thank you