What are common server-side issues, like MySQL connection errors, that can affect PHP applications?

One common server-side issue that can affect PHP applications is MySQL connection errors. This can occur due to incorrect database credentials, server downtime, or exceeding the maximum number of connections. To solve this issue, you can check the database credentials, ensure the MySQL server is running, and adjust the maximum number of connections if needed.

// Database credentials
$servername = "localhost";
$username = "username";
$password = "password";
$database = "dbname";

// Create connection
$conn = new mysqli($servername, $username, $password, $database);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}