How can PHP be used to check for past dates that have not been marked as used in a database for space utilization?

To check for past dates that have not been marked as used in a database for space utilization, we can query the database for all past dates and then check if any of them have not been marked as used. This can be achieved by comparing the list of past dates with the list of dates marked as used in the database.

// Connect to the database
$connection = mysqli_connect("localhost", "username", "password", "database");

// Query the database for all past dates
$query = "SELECT date FROM dates WHERE date < CURDATE()";
$result = mysqli_query($connection, $query);

// Fetch the results and check for unused dates
while ($row = mysqli_fetch_assoc($result)) {
    $date = $row['date'];
    
    // Check if the date is not marked as used
    $check_query = "SELECT * FROM space_utilization WHERE date = '$date'";
    $check_result = mysqli_query($connection, $check_query);
    
    if (mysqli_num_rows($check_result) == 0) {
        echo "Unused date found: $date\n";
    }
}

// Close the database connection
mysqli_close($connection);