Sorry to ask such a basic question, but I just can't figure this out from the user's manual and a lot of experimentation. I have one file which is a roster of students at our summer workshop. It tallies up the total amount of tuition paid. I have a second file which keeps track of the budget -- expenses, income, etc. How do I link these two files so that total tuition (calculated in file 1) shows up in file 2?

Thanks very much.

George Johnson

For total tuition paid, you can either calculate it in file 1 and then display it in file 2, or calculate it directly in file 2. In either case, create a field in file 1 and call it U1. This is a calc field, number, equal to 1. In file 2, make a global number field--call it U1g. Enter a value of 1 into this field. Now create a relationship from this global field to the calc field in file 1, and you will have available in file 2 every field for every record from file 1.

Now you can either display the TotalTutition calc field from file 1 directly in file 2, or you can create a calc field in file 2 = (sum ( Relationship::IndividualTuition ) ). Either way works.

Jerry

Thank you very much! This is great. Can you explain exactly what function the two U fields are performing? I'm just beginning to understand how all this works.

George

Say you have two files: Advisors and Students. In Advisors, there is a field called SocSecNum (forgive me if you're not American--substitute GovernmentID if you wish). In Students, there is a field called AdvisorID. If you create a relationship from Advisors.SocSecNum to Students.AdvisorID, you can now view and manipulate data that resides in the Students file FROM WITHIN the Advisors file. If you get the picture, you can see why this may be useful. (Incidentally, i chose Social Security Number because it's guaranteed to be unique, a very important feature of relationships like this one.)

This allows each record in Advisors to view/manipulate a selected set of records in Students. But sometimes you want one record in a file to be able to view/manipulate ALL records from another file, as in your tuition example above. That is where the U1::U1g relationship comes in; now, every record in the parent file (Budget.fp7) has the ability to read from every record in the child file (Students.fp7), which is a good method for totalling tuitions.

I can't recommend any books on relational database design, but i CAN recommend that you learn as much about it as you can. It's where the real usefulness of a database comes in; without relational structure, you may as well use a spreadsheet.

Clear things up any?

Jerry

Thank you very much again for taking the time to explain this. You've definitely made the concepts clearer to me.