How can PHP developers effectively troubleshoot and debug issues related to MySQLi database connections and queries?

To troubleshoot and debug MySQLi database connection and query issues in PHP, developers can start by checking the connection status, error messages, and query results. They can use functions like mysqli_connect_error() to display connection errors and mysqli_error() to show query errors. Additionally, developers can enable error reporting and logging to capture any issues that may arise during database operations.

// Example code snippet to troubleshoot MySQLi database connection
$conn = mysqli_connect($servername, $username, $password, $dbname);

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

// Example code snippet to troubleshoot MySQLi query
$sql = "SELECT * FROM users";
$result = mysqli_query($conn, $sql);

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