WP tax_query

function advanced_product_search_filter($query)
{
  if(!is_admin() &&
     is_main_query() &&
     is_search() && $query->query_vars['post_type'] == 'product')
  {
    $keyword = $_GET['s'];

    if($_GET['exactly'])
      $keyword = $_GET['s'] . ' "'. $_GET['exactly'] . '"';

    if($_GET['without'])
    {
      $excluded = exclude_product_keyword_search($_GET['without'],
                    $_GET['pname'],
                    $_GET['pcode']
                  );
      $query->set('post__not_in', $excluded);
    }

    if($_GET['pname'])
      $query->set('s', $keyword);
    else
      $query->set('s', '');

    if($_GET['pcode'])
    {
      $tax_queries = $query->get('tax_query');
      $tax_queries[] = array(
        array(
          'taxonomy' => 'pa_ordering-code',
          'field' => 'name',
          'terms' => array($keyword),
          'operator' => 'LIKE'
        )
      );
      $query->set('tax_query', $tax_queries);
    }
  }
}