One more guess: Try explicitly aliasing the fields of interest and using those aliases exclusively throughout the rest of the expression.
SELECT p.pk_ProductID as pid, p.Description as dsc, SUM(i.Quantity) as totl FROM invoice_invoicelines_Product p JOIN invoice_InvoiceLines i ON pid = i.fk_ProductID WHERE pid IN (1,2,3) AND i.fk_InvoiceID IN (1,2,3) GROUP BY pid; Note that I moved the invoiceID clause out of the join condition into the where filter. The ON clause should only contain expressions of relational interest. On Thu, Oct 22, 2015, 6:00 PM Don Wieland <d...@pointmade.net> wrote: > > > On Oct 22, 2015, at 2:41 PM, Michael Dykman <mdyk...@gmail.com> wrote: > > > > I'm not at a terminal but have you tried grouping by p.pk_ProductID > instead > > of i.fk...? It is the actual value you are selecting as well as being on > > the primary table in the query. > > Yeah I tried that - actually the SUM I need is on the JOIN relationship - > results should be: > > 1,Banana,3 > 2,Orange,5 > 3,Melon,6 > > Thanks! > > Don Wieland > d...@pointmade.net > http://www.pointmade.net > https://www.facebook.com/pointmade.band > > > > >