icl_translations - find rows where language_code is not set

<?php
    global $wpdb;
    $sql = "
   SELECT
    p.ID, p.post_title
   FROM {$wpdb->posts} p
    LEFT JOIN {$wpdb->prefix}icl_translations t
    on p.ID = t.element_id AND t.element_type = concat('post_' , p.post_type)
    WHERE t.language_code = '' AND NOT post_status IN ('auto-draft') AND NOT post_type IN ('revision')
    ";

    $orphans = $wpdb->get_results($sql);

    if($orphans) {
            echo '<h2>Orphan posts:</h2>';
            echo '<ul>';
            foreach ( $orphans as $orphan ) {
                    $url = get_edit_post_link( $orphan->ID );

                    echo '<li>';
                    echo '<a href="' . $url . '" target="_blank">';
                    echo $orphan->post_title;
                    echo '</a>';
                    echo '</li>';
            }
            echo '</ul>';
    } else {
            echo '<h2>No orphan posts!</h2>';
    }

    ?>