Allows you to update the taxonomy term order within the term_relationship table in WordPress

set_taxonomy_term_term_order.php

<?php
/**
 * Update an objects term order in the term relationships table
 * @param int $term_order
 * @param int $object_id post_od
 * @param int $tt_id term_taxonomy_id
 *
 * @return int
 */
function set_taxonomy_term_term_order( $term_order, $object_id, $tt_id ) {
	global $wpdb;

	return $wpdb->query( $wpdb->prepare(
			"
	 		UPDATE $wpdb->term_relationships
			SET term_order = %d
			WHERE object_id = %d
			AND term_taxonomy_id = %d
			",
			$term_order,
			$object_id,
			$tt_id
	) );
}