I'm working on writing an app in Zope and would like to try using the Zope object database exclusively. The problem I run into is how to best go about modeling relational data. For instance, I might have a list of courses and a list of students. If I create a course object and put student objects under it, I'll end up with duplicate student objects as students are in more than one course: Basketweaving Trent Eve Alice Object-Relational Modeling 101 Bob Trent Alice Obviously if I do it the other way around, and put courses inside student objects, I have the same problem. I need to do a many-to-many relationship. So do I just start using object IDs as pointers to objects separate hierarchies? Courses Basketweaving Object-Relational Modeling 101 Students Trent Eve Alice Bob Let me know what you guys think. Thanks, pablos. -- Paul Holman Kadrevian Nonlinear Accelerator pablos@kadrevis.com 415.420.3806