Adding up all multiple rows

Hi,

I have this but it does not work. I wish to add up all the rows but it does not add them. What am i doing wrong?

$sql= mysql_query("SELECT * FROM `table` WHERE MONTH(date) = '$smonth'");
	while ($row = mysql_fetch_assoc($sql)) {
		$total_hours = $row['hours']++;
	}
$total = ($total_hours * 15);

PHP:

Cheers,
Adam

 

$total_hours = $total_hours + $row['hours'];

and add this before the sql query:
$total_hours = 0;

 

$total_hours = $row['hours']++;
Your code above keep re-assign a new value for $total_hours ( in fact, $total_hours + 1 )

You should make it as:
$total_hours += $row['hours'];

Basically the same as the post above.