Now we will configure the PHP web application to connect to the MySQL database on the separate server.
Install the MySQL client on the web server:
sudo apt update
sudo apt install mysql-client -y
Next, test the connection to the MySQL server:
mysql -h 192.168.85.139 -u todo_user -p
Enter the password for todo_user when prompted. If the connection is successful, you’ll see the MySQL prompt:

In the PHP application’s db.php file, update the connection details to reflect the IP address of the MySQL server and the credentials for the newly created todo_user.
Edit the db.php file:
<?php
session_start();
$host = "192.168.85.139"; // Remote MySQL server IP
$user = "todo_user"; // Remote MySQL user
$password = "password"; // User password
$dbname = "todo_db"; // Database name
try {
$dsn = "mysql:host=$host;dbname=$dbname;charset=utf8mb4";
$pdo = new PDO($dsn, $user, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
} catch(PDOException $e) {
die("Database Connection Failed: " . $e->getMessage());
}
?>