I have confirmed that the part
, COALESCE((SELECT SUM(PurchaseBillItemInner.bQty)

If I remove the SUM() I get an error that there are multiple records returned in a singleton select.  There is an iID field on each row of each table (I have tried to use it to no avail) that can distinguish both these rows being returned but I am not able to figure out how.

Please advise

Kind regards
Bhavbhuti