Entity Relationship Diagrams explained using the Emergency Medical Hologram's medical database (from Star Trek:Voyager) as an example.

1. Entity Relationship Diagrams

5. Prescription

6. Prescription

7. Prescription Dr. Lewis Zimmerman 459 Patient name: Tom Paris Stardate: 41153.7 Drug: Tri-Ox Compound Take twice a day Dr. Lewis Zimmerman 459 Patient name: Tom Paris Stardate: 41153.7 Drug: Tri-Ox Compound Take twice a day

8. Prescription Dr. Lewis Zimmerman 459 Patient name: Tom Paris Stardate: 41153.7 Drug: Tri-Ox Compound Take twice a day Doctor Patient Date Drug Frequency Prescription number Dr. Lewis Zimmerman 459 Patient name: Tom Paris Stardate: 41153.7 Drug: Tri-Ox Compound Take twice a day

9. Prescription PrescriptionID DoctorName PatientName DrugName Date Frequency

10. Prescription PrescriptionID DoctorName PatientName DrugName Date Frequency Is this a good and sufficient representation ?????

11. Prescription 3 37389.5 Tri-Ox T’Pol Dr. Phlox 9 4 45673.4 Hyronalin Katherine Janeway Dr. L. Zimmerman 8 5 42604.4 Tri-Ox Tom Paris Dr. Lewis Zimmerman 7 90 42765.5 Priaxate Tom Paris L. Zimmerman 6 2 48796.6 Synaptizine Odo Dr. Bashir 5 1 45912.3 Hyronalin Lt. Data Dr. Beverly Crusher 4 7 42235.2 Tri-Ox Harry Kim Lewis Zimmerman 3 3 45432.1 Hyronalin Odo Dr. Julian Bashir 2 2 42231.2 Tri-Ox Tom Paris Dr. Lewis Zimmerman 1 Frequency (per day) Date Drug Name Patient Name Doctor Name Prescription ID

15. Prescription 3 37389.5 Tri-Ox T’Pol Dr. Phlox 9 4 45673.4 Hyronalin Katherine Janeway Dr. L. Zimmerman 8 5 42604.4 Tri-Ox Tom Paris Dr. Lewis Zimmerman 7 90 42765.5 Priaxate Tom Paris L. Zimmerman 6 2 48796.6 Synaptizine Odo Dr. Bashir 5 1 45912.3 Hyronalin Lt. Data Dr. Beverly Crusher 4 7 42235.2 Tri-Ox Harry Kim Lewis Zimmerman 3 3 45432.1 Hyronalin Odo Dr. Julian Bashir 2 2 42231.2 Tri-Ox Tom Paris Dr. Lewis Zimmerman 1 Frequency (per day) Date Drug Name Patient Name Doctor Name Prescription ID

16. Prescription 3 37389.5 Tri-Ox T’Pol 4 9 4 45673.4 Hyronalin Katherine Janeway 1 8 5 42604.4 Tri-Ox Tom Paris 1 7 90 42765.5 Priaxate Tom Paris 1 6 2 48796.6 Synaptizine Odo 2 5 1 45912.3 Hyronalin Lt. Data 2 4 7 42235.2 Tri-Ox Harry Kim 1 3 3 45432.1 Hyronalin Odo 2 2 2 42231.2 Tri-Ox Tom Paris 1 1 Frequency (per day) Date Drug Name Patient Name Doctor ID Prescription ID

18. Prescription 3 37389.5 Tri-Ox T’Pol 4 9 4 45673.4 Hyronalin Katherine Janeway 1 8 5 42604.4 Tri-Ox Tom Paris 1 7 90 42765.5 Priaxate Tom Paris 1 6 2 48796.6 Synaptizine Odo 2 5 1 45912.3 Hyronalin Lt. Data 2 4 7 42235.2 Tri-Ox Harry Kim 1 3 3 45432.1 Hyronalin Odo 2 2 2 42231.2 Tri-Ox Tom Paris 1 1 Frequency (per day) Date Drug Name Patient Name Doctor ID Prescription ID

19. Prescription 3 37389.5 Tri-Ox 6 4 9 4 45673.4 Hyronalin 5 1 8 5 42604.4 Tri-Ox 1 1 7 90 42765.5 Priaxate 1 1 6 2 48796.6 Synaptizine 2 2 5 1 45912.3 Hyronalin 4 2 4 7 42235.2 Tri-Ox 3 1 3 3 45432.1 Hyronalin 2 2 2 2 42231.2 Tri-Ox 1 1 1 Frequency (per day) Date Drug Name Patient ID Doctor ID Prescription ID

21. Prescription 3 37389.5 Tri-Ox 6 4 9 4 45673.4 Hyronalin 5 1 8 5 42604.4 Tri-Ox 1 1 7 90 42765.5 Priaxate 1 1 6 2 48796.6 Synaptizine 2 2 5 1 45912.3 Hyronalin 4 2 4 7 42235.2 Tri-Ox 3 1 3 3 45432.1 Hyronalin 2 2 2 2 42231.2 Tri-Ox 1 1 1 Frequency (per day) Date Drug Name Patient ID Doctor ID Prescription ID

22. Prescription 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID

24. Prescription Drug Patient Doctor 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

25. Prescription Drug Patient Doctor

27. Prescription Drug Patient Doctor 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

28. Prescription Drug Patient Doctor Text Numbers Text Text 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

29. Prescription Drug Patient Doctor Transactional Table Master Table Master Table Master Table 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

31. Prescription Drug Patient Doctor 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

32. Prescription Drug Patient Doctor Tricordrazine 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

34. Prescription 3 37389.5 Tri-Ox T’Pol Dr. Phlox 9 4 45673.4 Hyronalin Katherine Janeway Dr. L. Zimmerman 8 5 42604.4 Tri-Ox Tom Paris Dr. Lewis Zimmerman 7 90 42765.5 Priaxate Tom Paris L. Zimmerman 6 2 48796.6 Synaptizine Odo Dr. Bashir 5 1 45912.3 Hyronalin Lt. Data Dr. Beverly Crusher 4 7 42235.2 Tri-Ox Harry Kim Lewis Zimmerman 3 3 45432.1 Hyronalin Odo Dr. Julian Bashir 2 2 42231.2 Tri-Ox Tom Paris Dr. Lewis Zimmerman 1 Frequency (per day) Date Drug Name Patient Name Doctor Name Prescription ID

35. Prescription Tricordrazine Tricordrazine Tricordrazine Tricordrazine 3 37389.5 Tri-Ox T’Pol Dr. Phlox 9 4 45673.4 Hyronalin Katherine Janeway Dr. L. Zimmerman 8 5 42604.4 Tri-Ox Tom Paris Dr. Lewis Zimmerman 7 90 42765.5 Priaxate Tom Paris L. Zimmerman 6 2 48796.6 Synaptizine Odo Dr. Bashir 5 1 45912.3 Hyronalin Lt. Data Dr. Beverly Crusher 4 7 42235.2 Tri-Ox Harry Kim Lewis Zimmerman 3 3 45432.1 Hyronalin Odo Dr. Julian Bashir 2 2 42231.2 Tri-Ox Tom Paris Dr. Lewis Zimmerman 1 Frequency (per day) Date Drug Name Patient Name Doctor Name Prescription ID

37. Prescription Tricordrazine Tricordrazine Tricordrazine 3 37389.5 Tri-Ox T’Pol Dr. Phlox 9 4 45673.4 Hyronalin Katherine Janeway Dr. L. Zimmerman 8 5 42604.4 Tri-Ox Tom Paris Dr. Lewis Zimmerman 7 90 42765.5 Priaxate Tom Paris L. Zimmerman 6 2 48796.6 Synaptizine Odo Dr. Bashir 5 1 45912.3 Hyronalin Lt. Data Dr. Beverly Crusher 4 7 42235.2 Tri-Ox Harry Kim Lewis Zimmerman 3 3 45432.1 Hyronalin Odo Dr. Julian Bashir 2 2 42231.2 Tri-Ox Tom Paris Dr. Lewis Zimmerman 1 Frequency (per day) Date Drug Name Patient Name Doctor Name Prescription ID

40. Prescription Drug Patient Doctor 3 37389.5 1 6 4 9 4 45673.4 2 5 1 8 5 42604.4 1 1 1 7 90 42765.5 4 1 1 6 2 48796.6 3 2 2 5 1 45912.3 2 4 2 4 7 42235.2 1 3 1 3 3 45432.1 2 2 2 2 2 42231.2 1 1 1 1 Frequency (per day) Date Drug ID Patient ID Doctor ID Prescription ID Priaxate 4 Synaptizine 3 Hyronalin 2 Tri-Ox 1 Drug Name Drug ID T’Pol 6 Katherine Janeway 5 Lt. Data 4 Harry Kim 3 Odo 2 Tom Paris 1 Patient Name Prescription ID Dr. Phlox 4 Dr. Beverly Crusher 3 Dr. Julian Bashir 2 Dr. Lewis Zimmerman 1 Doctor Name Doctor ID

41. Now when we insert a record

42. Now when we insert a record PrescriptionID DoctorID PatientID DrugID Date Frequency

43. Prescription Insert new prescription record

44. Prescription Insert new prescription record Drug Check if the drug on the prescription is a real and existing drug

45. Prescription Drug Insert new prescription record Patient Check if the patient on the prescription is a real and existing patient

46. Prescription Drug Insert new prescription record Patient Check if the doctor on the Prescription is a real and existing doctor Doctor

47. Prescription Drug Patient Doctor

48. Prescription Drug Patient Doctor DrugID PatientID DoctorID

49. Prescription Drug Patient Doctor DrugID PatientID DoctorID PrescriptionID DoctorID PatientID DrugID Date Frequency DrugID DrugName RecommendedDosage Side-Effects PatientID PatientName PatientAddress Sympthoms Occupation DoctorID DoctorName Qualifications

50. Prescription Drug Patient Doctor DrugID PatientID DoctorID PrescriptionID DoctorID PatientID DrugID Date Frequency DrugID DrugName RecommendedDosage Side-Effects DoctorID DoctorName Qualifications PatientID PatientName PatientAddress Sympthoms Occupation