is_main_query()) { return $query; } if (!empty($_GET['external_ref_ord_no'])) { $external_ref_ord_no = sanitize_text_field($_GET['external_ref_ord_no']); $meta_query = $query->get('meta_query') ? $query->get('meta_query') : array(); $meta_query[] = array( 'key' => '_external_ref_ord_no', 'value' => $external_ref_ord_no, 'compare' => 'LIKE', ); $query->set('meta_query', $meta_query); } return $query; } }