Table design - reducing number of entities

Previously in my ERD there have been separate entities for 'Home Address' & 'Semester Address' which the 'Student' has foreign keys for. I was thinking of just having an 'Address' entity which that 'Student' has two foreign keys for - one for each address type. Is this ok to do? Will I lose any marks for modelling like this? I suppose the correct way to do this is to use a many to many between 'Student' and 'Address' now and use a juntion entity, rather than use two foreign keys?

This is the same for the 'Supervisor' and 'Training Offficer' entities which the student has - why not just use an 'Employee' entity but is it correct to use a foreign key for supervisor and training officer which both reference employee - that removes the need to use a juntion entity!

DJW Received on Wed Nov 30 2005 - 09:22:47 CET