subtotals in a portal

[ruthcarlton]

I have an sales/inventory system which calculates totals, but now I need to provide a way to view subtotals by tour name in a portal.

The "sales" file creates a record (thru an import) for every item everytime there is an event - they appear in a portal in another file as a spreadsheet to record sales. Each record has a serial # for the item, a date and a tour name. Totals are calculated thru a self-join relationship based on serial#.

I figured a great way to get subtotals by tourname would be with a global and a calulation field in which the serial number appears if the TourName = gTourName, and then have a relationship based on this new field, but Filemaker won't let me have a relationship based on a calculation with a global.

I've thought about using a loop and to set the field, but this file is going to get big quickly and it's going to be very slow.

Any other suggestions?