totalling fields in a portal

[fujay]

I am making a simple database that will keep a running bill for customers in a bar. I have two tables:

* the main table that holds the seat number where the person is sitting, date etc. There is one record for each person (or group of people).
* a table for orders - one record for each drink or food item ordered.

I have put a portal in the main table that shows each of the food items that have been ordered, and the cost of those items. I want to put a total field into the main table that shows the total cost of all food and drink items ordered in that table. How can I do this?

 

[fujay]

Sorry, I forgot to add, I am using filemaker pro 7.0

 

[JeanW]

Oops, for some reason I missed this one...

In your order table, make sure you have also the seat number or every other ID to identify the 'paying part'.

Make a sort of self join relationship on this field.
This will bring every 'to pay' item together in 1 portal.

Make sum, based upon the relationship for the total.

HTH