Cron作业返回错误消息

Question

我试图通过cron作业连接到我的数据库。但是我不断收到一条错误消息。经过许多令人沮丧的时间后在这里张贴求助。

我的cron脚本PHP文件：

<?php 
define("HOST","localhost"); 
define("USERNAME","user_muser"); 
define("PASSWORD","*********"); 
define("DB_DATABASE","databasename"); 

$conn = mysqli_connect('HOST', 'USERNAME', 'PASSWORD','DB_DATABASE'); 

// Check connection 
if (mysqli_connect_errno()) 
{ 
"Failed to connect to MySQL: " . mysqli_connect_error(); 
} 
// Check if server is alive 
if (mysqli_ping($conn)) 
{ 
"Connection is ok!"; 
} 
else 
{ 
"Error: ". mysqli_error($conn); 
} 
mysqli_close($conn); 
?> 

这是我收到的错误：

mysqli_connect(): (HY000/2005): Unknown MySQL server host 'HOST' (0) 
mysqli_ping() expects parameter 1 to be mysqli 
mysqli_error() expects parameter 1 to be mysqli 
mysqli_close() expects parameter 1 to be mysqli 

任何帮助吗？谢谢！

Answer 1

你在引用常量，这使得它们成为字符串。

define("HOST","localhost"); 
define("USERNAME","user_muser"); 
define("PASSWORD","*********"); 
define("DB_DATABASE","databasename"); 

$conn = mysqli_connect(HOST, USERNAME, PASSWORD, DB_DATABASE); 

Answer 2

你应该在引号外写下constants如下。否则，他们通常是字符串。

$conn = mysqli_connect(HOST, USERNAME, PASSWORD,DB_DATABASE);