根目录/config_test/config.php
[php]
<?php
define("UserName","root");
define("PassWord","root");
define("ServerName","localhost");
?>

[/php]

根目录/class_test/dbcon.php[php]
<?php
include("../config_test/config.php");
function dbcon(){
$db=mysql_connect(ServerName,UserName,PassWord) or die("error:sorry db connect error");
mysql_select_db("djt",$db) or die("error:".mysql_error());
return $db;
}
?>
[/php]

根目录/test_a.php[php]
<?php
include("class_test/dbcon.php");
$db=dbcon();
?>
[/php]

错误提示如下:
Warning: include(../config_test/config.php) [function.include]: failed to open stream: No such file or directory in D:\Apache Group\Apache2\htdocs\class_test\dbcon.php on line 14

Warning: include() [function.include]: Failed opening '../config_test/config.php' for inclusion (include_path='.;C:\php5\pear') in D:\Apache Group\Apache2\htdocs\class_test\dbcon.php on line 14

Notice: Use of undefined constant ServerName - assumed 'ServerName' in D:\Apache Group\Apache2\htdocs\class_test\dbcon.php on line 25

Notice: Use of undefined constant UserName - assumed 'UserName' in D:\Apache Group\Apache2\htdocs\class_test\dbcon.php on line 25

Notice: Use of undefined constant PassWord - assumed 'PassWord' in D:\Apache Group\Apache2\htdocs\class_test\dbcon.php on line 25

Warning: mysql_connect() [function.mysql-connect]: Unknown MySQL server host 'ServerName' (11001) in D:\Apache Group\Apache2\htdocs\class_test\dbcon.php on line 25
error:sorry db connect error

[ 本帖最后由 yiyamzen 于 2006-6-24 11:19 AM 编辑 ]