Field calculation question
Hello FM pro's out there. Can I create a field based on calculating the sum of a numeric field in a related table that only sums the records in the related table that match criterion in another field.
for example if I had Customers <---->Invoices<----->Lines<----->products(each product has field called category: sweaters,pants,shirts,etc...)
I am trying to create a table that will always have running total for how many sweaters I have sold to a given customer with a calculation. So that every time a line is added, the running total is always reflected in that table.
I know I can use a calculation to sum all the records for the customer. But how do I keep a running total based on the category for that customer?