Hi, I two questions regarding EER models that I would be grateful if anyone could help me out with.
I'm designing an EER diagram at the moment, I was wondering if for example I had data stored on someone that contained name, age and id number would name , age and id number just be attributes of the entity "stored data" or could I use Generalisation/Specialisation where "stored data" would be the top entity and name age and id number would be disjoint constraints?
Secondly, is it acceptable to draw seperate diagrams for the Generalisation/Specialisation part fo a databse model from the entity/relationship part or should all the parts of the EER model be drawn together?
Thanks for the answers I appreciate it. One last question - can I add generalisation/specialisation to attributes. Say for example I have sex as an attribute can I then add disjoint constraints of male/female to the attribute? And if so would I draw these in the same fashion as I would draw generalisation/specialisation constraints to an entity?