show cumulative/running total

I have a results page with a Date column where I'm displaying the total records grouped by month, in the following format:

MONTH TOTAL
Jan 16 2
Feb 16 4
Mar 16 6
Apr 16 6
May 16 11

My SELECT statement is as follows:

SELECT *, YEAR(StagingDate), MONTH(StagingDate), COUNT(*) as recordCount FROM clients JOIN accountants on clients.AccountantID = accountants.AccountantID WHERE StagingDate IS NOT NULL AND accountants.AccountantID = %s GROUP BY EXTRACT(YEAR_MONTH FROM StagingDate) ORDER BY StagingDate ASC.

I would now like to display a running total in another column, like this:

MONTH TOTAL RUNNING TOTAL
Jan 16 2 2
Feb 16 4 6
Mar 16 6 12
Apr 16 6 18
May 16 11 29

How would I change my SELECT statement to calculate this, or could it be done in PHP?

the running total cannot be done in the SQL. you would need to do it in the SQL.

before the repeat region that displays the records, declare a variable to hold the running total:
<?php
$runningTotal = 0;
?>

then add the recordset value to the running total where it gets desiplayd, and show it next to that:
for example:
show total:<?php echo($_RecordsetName['recordCount']);?>
Calculate running total: <?php $runningTotal = ($runningTotal + $_RecordsetName['recordCount']); ?>
Show running Total: <?php echo($runningTotal); ?>

Hi Jason, that does exactly what I was after, many thanks!

you're welcome.