我正在做一个PHP类的最终项目,我在验证代码时遇到了问题。在代码的else if部分,我总是在这两个else if语句中都得到一个错误,并且应用程序停止处理。下面的代码是一个.php文件的一部分,该文件包含一个用于设置提醒的超文本标记语言表单。 $error_message = "Selected date does not exist.
我在我的存储库中定义了这个函数,当我测试它时,它在我的数据库中工作得很好,所有的字段都包含值。 "SUM(january) as january,SUM(february) as february, SUM(march) as march, SUM(april) as april, SUM(may) as may, SUM(june) as june, SUM(july) as july, SUM(august) as august, sum(september) as