מוצרים שלא במלאי שיהיו בתחתית העמוד

add_filter('posts_clauses', 'sort_out_of_stock_products_last', 9999);
function sort_out_of_stock_products_last($clauses) {
    global $wpdb;

    if (is_shop() || is_product_category() || is_product_tag()) {
        $out_of_stock_products = $wpdb->get_col("SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_stock_status' AND meta_value = 'outofstock'");
        $out_of_stock_products_clause = implode(',', $out_of_stock_products);

        $clauses['orderby'] = "FIELD($wpdb->posts.ID, $out_of_stock_products_clause) ASC, $wpdb->posts.menu_order ASC";

        $clauses['join'] .= " LEFT JOIN $wpdb->postmeta istockstatus ON ($wpdb->posts.ID = istockstatus.post_id) ";
        $clauses['where'] .= " AND istockstatus.meta_key = '_stock_status' AND istockstatus.meta_value <> '' ";
    }

    return $clauses;
}