WP query order by taxonomy name

wp_query_order_by_taxonomy_name.php

<?php
function getTermOrderedIds($post_type, $taxonomy) {
    global $wpdb;
    $sql = "SELECT p.ID FROM $wpdb->posts p
        JOIN $wpdb->term_relationships tr ON (tr.object_id = p.ID)
        JOIN $wpdb->term_taxonomy tt ON (tt.term_taxonomy_id = tr.term_taxonomy_id AND tt.taxonomy = '$taxonomy')
        JOIN $wpdb->terms t ON (t.term_id = tt.term_id)
        WHERE p.post_status = 'publish' AND post_type = '$post_type' ORDER BY t.name ASC";
    $res = $wpdb->get_results($sql);
    if ($res) {
        $ids = array_map(function($e) {
            return $e->ID;
        }, $res);
        return $ids;
    }
    return false;
}

$ids = getTermOrderedIds('posttype_name', 'taxonomy_name');
$args = array(
    'post_type' => 'posttype_name',
    'post_status' => 'publish',
    'orderby' => 'post__in',
    'post__in' => $ids
);