Krijg de som van de MySQL-kolom in PHP

Je kunt het volledig afhandelen in de MySQL-query:

SELECT SUM(column_name) FROM table_name;

PDO gebruiken (mysql_query is verouderd)

$stmt = $handler->prepare('SELECT SUM(value) AS value_sum FROM codes');
$stmt->execute();

$row = $stmt->fetch(PDO::FETCH_ASSOC);
$sum = $row['value_sum'];

Of gebruik mysqli:

$result = mysqli_query($conn, 'SELECT SUM(value) AS value_sum FROM codes'); 
$row = mysqli_fetch_assoc($result); 
$sum = $row['value_sum'];