PHP常量未定义 [英] PHP constant not defined

问题描述

我正在使用一个数据库项目，我创建了一个单独的文件，以保持所有的数据库信息名称'config.php'。对于数据库，我将另一个'database.php'文件保存在同一目录中。

I am working with a database project and I have created a seperate file to keep all the database information name 'config.php'. And for the database I keep another 'database.php' file in the same directory.

----------------- ------- config.php --------------

------------------------config.php--------------

<?php
defined('DB_SERVER') ? null : define('DB_SERVER',"localhost");
defined('DB_USER')   ? null : define('DB_USER',"gallery");
defined('DB_PASS')   ? null : define('DB_PASS',"phpOTL123");
defined('DB_NAME')   ? null : define('DB_NAME',"photomania");
?>

--------------------- --- databae.php -------------

------------------------databae.php-------------

<?php
require_once("config.php");
class MySQLDatabase{
    private $conn;

    function __construct(){
        $this->open_connection();
    }
    public function open_connection(){
        $this->conn = mysqli_connect(DB_SERVER,DB_USER,DB_PASS);
        if(!$this->conn){
            die("Database Connection Failure :(".mysql_errno());
        }else{
            $db_select = mysqli_select_db($this->conn,DB_NAME);
            if(!$db_select){
                die("Can't select the database".mysql_errno());
            }
        }
    }
    public function close_connection(){
        if(isset($this->conn)){
            mysqli_close($this->conn);
            unset($this->conn);
        }
    }
}

$database = new MySQLDatabase;
?>

---

问题是当我将database.php包含在索引文件中时使用

require_once("../includes/database.php");

it gives following errors. 

注意：使用未定义的常量DB_SERVER - 在
中假定为DB_SERVERC：\XAMPP\htdocs\gallery\includes\database.php在第11行上

Notice: Use of undefined constant DB_SERVER - assumed 'DB_SERVER' in C:\XAMPP\htdocs\gallery\includes\database.php on line 11

注意：使用未定义的常量DB_USER - 在
中假定为DB_USERC：\XAMPP\htdocs\gallery\includes\database.php在第11行

Notice: Use of undefined constant DB_USER - assumed 'DB_USER' in C:\XAMPP\htdocs\gallery\includes\database.php on line 11

注意：使用未定义的常量DB_PASS - 在
中假定为DB_PASSC：\XAMPP\htdocs\gallery\includes\database.php on line 11

Notice: Use of undefined constant DB_PASS - assumed 'DB_PASS' in C:\XAMPP\htdocs\gallery\includes\database.php on line 11

警告：mysqli_connect（）：php_network_getaddresses：getaddrinfo
失败：未知此类主机。 in
C：\XAMPP\htdocs\gallery\includes\database.php on line 11

Warning: mysqli_connect(): php_network_getaddresses: getaddrinfo failed: No such host is known. in C:\XAMPP\htdocs\gallery\includes\database.php on line 11

警告：mysqli_connect（）：（HY000 / 2002）：php_network_getaddresses：
getaddrinfo failed：没有这样的主机是已知的。 in
C：\XAMPP\htdocs\gallery\includes\database.php on line 11数据库
连接失败：（

Warning: mysqli_connect(): (HY000/2002): php_network_getaddresses: getaddrinfo failed: No such host is known. in C:\XAMPP\htdocs\gallery\includes\database.php on line 11 Database Connection Failure :(

---

任何帮助

---

Any help ??????

推荐答案

您的问题似乎在下列行中

you problem seems to lie in following line

require_once("config.php");

尝试替换为

require_once(dirname(__FILE__) . DIRECTORY_SEPARATOR . "config.php");

这篇关于PHP常量未定义的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！