问自定义表中的序列号未出现在woocommerce_email_before_order_table操作中

EN

prefix ."ipn_data_tbl";

 ///////BELOW is using 'seq Order No' plugin..this checks if WOO O/N or plugins O/N.
   if (empty($order->get_id))  {      
    $woo_order_id = $order->get_order_number();
      }             
 elseif (empty($order->get_order_number))  {
    $woo_order_id  = $order->get_id();
     }

 ///check order ID and Table name are there:
if (!empty($woo_order_id && $ipn_tables )) {
   echo 'ORDER ID:  '.$woo_order_id.'
'; // echos the Order ID - appears on "Thanks for shopping with us" email
   echo 'TABLE NAME:  '.$ipn_tables.'
';   // echo my Custom table name - appears on "Thanks for shopping with us" email
   ////But the below $licence variable dosent. I think its a timing thing. 
   //$license = $wpdb->get_var(" SELECT serial_no FROM $ipn_tables WHERE woo_order_id = $woo_order_id " );
   $license = $wpdb->get_var( $wpdb->prepare( "SELECT * FROM {$ipn_tables} WHERE woo_order_id = %s", $woo_order_id ) );
      }

   if ( $email->id == 'customer_completed_order' ){
  
      printf( '' .__( 'Your Software Serial Number:  '.''.$license ));
   } 
}//function-END
?>忘记显示MyPHPAdmin表：编辑:我应该提到我把orderID和表的许可检查放在这里，只是为了看看它是否是checked..it，我的get_var查询不工作(空的？)但是，在我编辑的其他PHP页面中也使用了相同的查询。