Circular relationship issue (in FM7)

[crumpsbro]

I'm having some trouble setting up the relationships between a few tables, getting a message that there cannot be more than one relational path between two tables in the graph (and Filemaker then wants to add a new Occurence to handle it). I'm more familiar with setting up data models using SQL than I am with Filemaker, and I suspect that my design may be fine for SQL but not Filemaker. So I'm hoping to receive some advice about what to do in this situation.

There are Students, Teachers, and Courses. A Course can have multiple Students, and multiple Teachers. This is all pretty straightforward. The complication is that in my situation, the same person could be both a Student in some Courses and a Teacher in other Courses. In my current setup, I have a Contact table to represent individuals. I then have a Student table that is linked to Contacts, and a Teacher table that is linked to Contacts. I have a Courses table which contains information about a specific course, and then join tables TeacherCourses and StudentCourses to track which teachers / students were in each course.

The TeacherCourses table has a TeacherID and CourseID. I am able to link these to the relevant tables. The StudentCourses table has a StudentID and CourseID. I am able to link up the StudentID to the Student table, but when I try to link up the CourseID (in StudentCourses) to the Courses table, I get the message from Filemaker that there cannot be more than one relational path between the tables.

Any suggestions on how to modify my table structure to accommodate Filemaker's relationship structure?

[Søren Dyhr]

Who, have told you the RG was a ERD...

Any suggestions on how to modify my table structure to accommodate Filemaker's relationship structure?

The graph isn't a table structure, but a structure of table occurences actually....

This video explains it:

http://www.filemakermagazine.com/videos/graph-rules-four-rules-to-remember.html

However, is this by all means the best explanation of what's going on:

http://www.digfm.org/ref/FM7_key_concepts.pdf

--sd

[corn]

Don't think of it as a data model structure and you'll be fine. Your table structure is okay, you just need to layout your graph a bit differently. You will need to have more than one table occurrence for at least one of your tables to lay this out properly.