Question

Consider the following information about a patient database:

A patient is identified by patient id, and admission date.

A patient must be either an Emergency patient or a resident patient.

We must record the checkback date for Emergency patient.

Only resident patient is assigned to one room. Room has a unique number, degree, and floor number.

For each room there are a number of beds each of which has a bed number, specification. If a room is deleted, you need not keep track of its beds any longer.

Both emergency patient and resident are cared for by a responsible Doctor. Doctor is identified by Doctor number. For each Doctor, the name, several specialty, and years of experience must be recorded.

Doctors prescribe medicine for patients. Medicine is identified by trade name that has scientific name and formula. The medicine depends on another medicine to be taking before.

A doctor could prescribe one or more drugs for several patients, and a patient could obtain prescriptions from several doctors. Each prescription has a date and a quantity of medicine.

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Draw an ER/EER diagram that captures the above information.

Answer 1

Zero to many is used because there can be a moment where DoctorNum, PatientID and paitent can be one of the best day of my life.