In what scenarios would it be more efficient to calculate date differences using SQL queries instead of PHP?

Calculating date differences using SQL queries can be more efficient when working with large datasets or when performing complex calculations involving multiple date fields in a database. By utilizing SQL functions and operators, the database engine can handle the computation directly, reducing the amount of data that needs to be fetched and processed by PHP. This can lead to faster query execution times and improved overall performance.

// Example of calculating date differences using SQL queries in PHP

$query = "SELECT DATEDIFF(end_date, start_date) AS date_difference FROM table_name";
$result = mysqli_query($connection, $query);

if ($result) {
    while ($row = mysqli_fetch_assoc($result)) {
        echo "Date difference: " . $row['date_difference'] . " days<br>";
    }
} else {
    echo "Error: " . mysqli_error($connection);
}

mysqli_close($connection);