Question

Construct an E-R diagram for a hospital with a set of patients and a set of medical doctors. Associate with each patient a log of the various tests and examinations conducted. Use your best judgement to identify the attributes for each of those entities.

Answer 1

The above ER diagram has the following entities.

• Patient
• Employee
• Hospital
• Doctor
• Receptionist
• Room
• Medicine
• Record

Patient entity contains Patient ID, Name, Address, Sex, Phone No, Admitted date, Discharge date, Age as attributes. In Patient entity Patient ID is the primary key and Phone No and Medical records are multivalued attribute.

Hospital entity contains Hospital ID, Address, Name, Phone No as attributes where, Hospital ID is the primary key and Phone No is a multivalued attribute.

Employee enitity contains Employee ID, Sex, Phone No, Experience, Salary, Name, Qualification where Employee ID is the primary key, Phone No is a multivalued attribute and Name is a composite attribute.

Doctor entity consits of other three entities called Visiting, Permanent, and Resident which shows the designation of the doctors.

Receptionist entity has a relationship with record entity which contains Record No as primary key and Appointment attribute and Patient info attribute which is a multivalued attribute.

Room entity consists of Room ID as primary key and also a room type entity.

Medicine entity consists of Code as primary key and also attributes called Price and Description

Patient has a reltaion "Admitted in" with Hospital

Hospital has a relation "has" with Employee

Employee has a ISA relation with Doctor,Receptionist and Nurse

Doctor has a ISA relation with Visiting,Permanent,Intern

Nurse has a "Governs" relation with Room

Patient has a "billed for" relation with Treatment and Medicine

Patient has a "assigned to'' relation with Room