How can PHP developers ensure that users are notified when no data is available from a database query?

PHP developers can ensure that users are notified when no data is available from a database query by checking if the query returned any rows. If no rows are returned, they can display a message to the user indicating that no data is available. This can be achieved by using the mysqli_num_rows() function to check the number of rows returned by the query.

// Perform the database query
$result = mysqli_query($connection, "SELECT * FROM table_name");

// Check if any rows were returned
if(mysqli_num_rows($result) == 0) {
    echo "No data available";
} else {
    // Process the query results
    while($row = mysqli_fetch_assoc($result)) {
        // Display the data to the user
    }
}

// Free the result set
mysqli_free_result($result);