Removing duplicate tables from model.

[enthusiast]

Hello,

I'm building model that tracks event history for classes, class students and class masters.
I now have duplicated tables for event for each of these entities.
Id like to have only one set of tables for events and event types.

Diagram is better way to describe what I mean so here:
http://yfrog.com/jndiagramp

ClassMasters and ClassStudents are weak entities derived from Class and Person (not shown on diagram).
Each entity type may have several different types of history events.

It needs some kind of intermediate entity, so far i failed every attempt to create one because I can't enforce full referential integrity on it (e.g. when student is deleted, all history events go with him).
I that even possible to create such entity?

EDIT: preferably, I would stay away from triggers or stored procedures

Thank you.

[peter]

Hello enthusiast,

you say