How can error reporting and error handling functions like mysql_error() be effectively used to troubleshoot PHP scripts?

Error reporting and error handling functions like mysql_error() can be effectively used to troubleshoot PHP scripts by providing detailed error messages when something goes wrong during database operations. By using these functions, developers can quickly identify the root cause of issues and make necessary adjustments to their code to fix them. It is important to properly handle errors to prevent potential security vulnerabilities and ensure the smooth functioning of the application.

// Example of using mysql_error() to handle errors in PHP script
$conn = mysqli_connect("localhost", "username", "password", "database");

if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

$query = "SELECT * FROM users";
$result = mysqli_query($conn, $query);

if (!$result) {
    die("Query failed: " . mysqli_error($conn));
}

// Process the query result here

mysqli_close($conn);