Unknown MySQL server host 'DB_HOST' (0) - php

Question

I am trying to sent data to the server database, i implement it using wamp server it was working fine but when i installed the db on my domain and switched it to my domain its giving the following error.
I have kept my files inside a folder in root directory
Unknown MySQL server host 'DB_HOST' (0)
Below is my config file i am using to connect to the db
<?php
// Database configuration
define('DB_USERNAME', 'user');
define('DB_PASSWORD', 'xxxx');
define('DB_HOST', '192.210.195.245');
define('DB_NAME', 'tabanico_userlogin');
?>
here my code connecting db, config.php file contains the code pasted above
<?php
class DbConnect {
private $conn;
function __construct() {
// connecting to database
$this->connect();
}
function __destruct() {
$this->close();
}
function connect() {
include_once dirname(__FILE__) . './Config.php';
$this->conn = mysql_connect(DB_HOST, DB_USERNAME, DB_PASSWORD) or die(mysql_error());
mysql_select_db(DB_NAME) or die(mysql_error());
// returing connection resource
return $this->conn;
}
// Close function
function close() {
// close db connection
mysql_close($this->conn);
}
}
?>
and my file receiving data
<?php
include_once './DbConnect.php';
function createNewPrediction() {
$response = array();
$id = $_POST["id"];
$name = $_POST["name"];
$email = $_POST["email"];
$password = $_POST["password"];
$db = new DbConnect();
// mysql query
$query = "INSERT INTO login(id,name,email,password) VALUES('$id','$name','$email','$password')";
$result = mysql_query($query) or die(mysql_error());
if ($result) {
$response["error"] = false;
$response["message"] = "Prediction added successfully!";
} else {
$response["error"] = true;
$response["message"] = "Failed to add prediction!";
}
// echo json response
echo json_encode($response);
}
createNewPrediction();
?>
I have seen related post but didn't find useful answers. Can anyone help me in getting out of this. Thanks in advance.

Answer 1

Please post the code where you try to connect to the server. I guess you tried to connect using the following function:
mysql_connect('DB_HOST', 'DB_USERNAME', 'DB_PASSWORD');
Since you defined the host using define('DB_HOST', 'localhost');, you do not have to use apostrophes. DB_HOST is a constant here. So try to use to
mysql_connect(DB_HOST, DB_USERNAME, DB_PASSWORD);
instead. If you use apostrophes like in 'DB_HOST', it is interpreted as a string instead of the value of the constant DB_HOST containing localhost. That's a possible reason why you get the error that DB_HOST is an unknown host.
But please post the connection part of your code to see if that's really the mistake.