恒变量已经定义XAMPP错误

Question

我为故障排除有人和网站的错误之一是这样的：

Constant serverusername already defined in C:\xampp\htdocs\employee\inc\db.php on line 5 

db.php中的内容如下：

<?php 

//Database Connection Settings 
define ('hostnameorservername','localhost'); //Your server name or hostname goes in here 
define ('serverusername','root'); //Your database username goes in here 
define ('serverpassword',''); //Your database password goes in here 
define ('databasenamed','asset'); //Your database name goes in here 

global $connection; 
$connection = @mysql_connect(hostnameorservername,serverusername,serverpassword) or die('Connection could not be made to the SQL Server. Please report this system error at <font color="blue">[email protected]</font>'); 
@mysql_select_db(databasenamed,$connection) or die('Connection could not be made to the database. Please report this system error at <font color="blue">[email protected]</font>'); 
?> 

当我在整个目录中搜索“serverusername”，在其他任何地方我都找不到

:\xampp\htdocs\employee\inc\db.php on line 5 

H无论如何行：

include 'inc/db.php'; 

存在于众多的文件。

什么似乎是问题？我该如何解决它？预先感谢您

Answer 1

由于在同一页上多次包含db.php文件，可能会发生此问题。

试试这个：

include_once 'inc/db.php'; 

Answer 2

这种替换代码：

defined('hostnameorservername') or define('hostnameorservername', 'localhost'); 
defined('serverusername') or define('serverusername', 'root'); 
defined('serverpassword') or define('serverpassword', ''); 
defined('databasenamed') or define('databasenamed', 'asset');