is it okay to add some extra attributes to identify and to make the entities more identifiable. like is it okay to create an attribute called Appointment_ID in appointment table. Also, can there be tables without a primary key?

Please adhere to the provided specification. While you can include additional attributes such as 'appointment_id' for entity identification, ensure that your database maintains all relationships and constraints as outlined in the project sheet. "Neethu Mathew" <24*2*7*9@s*u*e*t*u*a*e*u*a*> wrote:

I have the same question, because if we can't make new ones then there's no reason to implement the Client superclass into the physical model, and its attributes should be just directly given to the Patient and Customer entities Also I'm pretty sure we are allowed to have tables without primary keys, they'll just be weak tables