Question 3: Medications 7 marks Databases in the field of healthcare can be extremely complicated, due to the large number of competing requirements and the need to maintain huge volumes of data for all aspects of patient care (such appointments, diagnoses, hospital visits, specialists, prescriptions, conditions, procedures, etc.). This question covers a data model for medications, which should enable such queries as 'find all medications (prescribed or otherwise) taken by a given patient', 'find all prescriptions written by a given doctor' or 'find all patients taking a given drug'. Construct an E/R diagram for the following data; ensure that all entities have associated primary keys. You may add surrogate keys but you will lose marks if you add surrogate keys in cases where they are unnecessary Patients have a provincial health number (PHN), which is unique, as well as a name and a home address Doctors have a name, office address and unique ID number. Medications have a drug ID number (DIN), a chemical name and may have several trade names. For example, ibuprofen is sold under the trade names 'Advil' and 'Motrin'. Not all medications have a trade name . Some medications are classified as over-the-counter, which means that patients can buy them without a prescription. However, prescriptions canstl be given for over-the-counter medica- tions . A prescription is written by a single doctor for a single patient. Each prescription is for a single medication. The prescription has an associated date and dosing instructions (e.g. 'take twice daily'). Note that the dosing instructions for a given medication may differ between prescriptions . A patient may receive multiple prescriptions for the same medication over time. For our purposes, you may assume that they will receive no more than one prescription of a given drug per day