Catch 22: Indexed can't be unstored

[Saubs]

I've found some useful threads explaining how to use multikeys in relationships, specifically how to use multiple calc fields as foreign keys. For example, one of these calc fields called cEnrollment might look like this:

GetNthRecord(students::studentName;1)&"¶"&

GetNthRecord(students::studentName;2)&"¶"&

GetNthRecord(students::studentName;3)&"¶"&

"ANY"

Here's my problem: Because the calc field must be indexed in order to be part of a foreign key, it can't be unstored. Consequently, whenever a student name is added or modified in the data entry layout, the cStudentList calc field does not 'get updated' with the new info. This is a problem for me, because obviously I need the student names in the calc field (foreign key) to accurately reflect the list of students in the data table. How can I remedy this?

Hope my post makes sense. Show some mercy please, I'm not an expert

Thanks in advance for your suggestions--

[mr_vodka]

Let talk about what you are trying to achieve here first. What is the purpose of this calc?

[Saubs]

I want to set values in global fields (primary keys) in order to filter the contents of a portal.

[mr_vodka]

The parent side does not need to be indexed. So if you are trying to filter out a portal, the global field would hold the values that you want to relate to the child records.

[David Jondreau]

I want to set values in global fields (primary keys) in order to filter the contents of a portal.

That's just how you're using Filemaker to accomplish something. What are you trying to do in context of the "real world".

What are the tables involved and what do they represent? Students is one obviously. What are the others that are involved in your problem? What do they represent? How are they related?

You're right, to do what you're asking requires indexing an unstored field, and that's impossible, but there's probably another way to accomplish the feature you're trying to add.

[Saubs]

Thanks for your replies--much appreciated. I will post a sample file next week so I can explain better.