I currently have a table that looks like this:
SELECT
spend.clientname,
spend.weekending,
spend.spend,
spend.reporttype
FROM spend
INNER JOIN `_vendor` ON spend.vendorname = `_vendor`.vendorname
INNER JOIN reportsourcetypes ON spend.reporttype = reportsourcetypes.reporttype
INNER JOIN mediatypes ON spend.mediatype = mediatypes.mediatype
INNER JOIN jobs ON spend.jobnumber = jobs.jobnumber AND spend.clientname = jobs.clientname
In the 'reporttype' field, I have variables such as "billed" and "received".
What I'm trying to create is a report that shows something like this:

The balance column would be a calculated function of 'Received' - 'Billed'.
How do I achieve this?