Design a class Patient Data Base that stores instances of Patient Record, as described in the previous project. The class should provide at least three query operations, as follows. Given a patient...

Design a class Patient Data Base that stores instances of Patient Record, as described in the previous project. The class should provide at least three query operations, as follows. Given a patient identification and date, the first operation should return the reason for the visit, and the second operation should return the treatment. The third query operation should return a list of dates, given a patient identification.