Cron作业返回错误消息

Question

I'm trying to connect to my database via cron job. However i keep receiving an error messages. After many frustrating hours im posting here for help.

My cron script php file:

 <?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);
?>

This is the error i received:

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

Any help? Thanks!

Answer 1

You're quoting constants, which makes them strings.

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

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

Answer 2

You should write constants out of quotes as following. Otherwise they are usual strings.

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