Sortable custom field values from all posts on a page template

Question

I was looking for a way to display a list of custom field from across all the posts on a custom made page template and I got the solution in this thread,.

As all the custom field values are strings only, I need the list to display in an alphabetical order. Is it possible ? Given is the code I am using currently that fetches me a nice unordered list, that gets the work done. If this is possible, Please suggest the change in code.

<?php
function get_meta_values( $key = '', $type = 'post', $status = 'publish' ) {
    global $wpdb;
    if( empty( $key ) )
        return;
    $r = $wpdb->get_col( $wpdb->prepare( "
        SELECT pm.meta_value FROM {$wpdb->postmeta} pm
        LEFT JOIN {$wpdb->posts} p ON p.ID = pm.post_id
        WHERE pm.meta_key = '%s' 
        AND p.post_status = '%s' 
        AND p.post_type = '%s'
        ", $key, $status, $type ) );

    return $r;
}
?>
<?php $my_list_items = get_meta_values( 'full_name' ); ?>
    <h3>Display a list of custom values :</h3>
    <ul>
        <?php foreach($my_list_items as $my_list_item) {
            echo '<li>' .$my_list_item. '</li>';
            } ?>
    </ul>

Answer 1

What if you use ORDER BY pm.meta_value ASC in WP db class:

$r = $wpdb->get_col( $wpdb->prepare( "
        SELECT pm.meta_value FROM {$wpdb->postmeta} pm
        LEFT JOIN {$wpdb->posts} p ON p.ID = pm.post_id
        WHERE pm.meta_key = '%s' 
        AND p.post_status = '%s' 
        AND p.post_type = '%s'
        ORDER BY pm.meta_value ASC
        ", $key, $status, $type ) );

That will provide you an ASCending ordered array.