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G4G0-1/Semester 1/Database Systems/Assignment/ER Diagram.md
2024-01-15 20:14:10 +00:00

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Key Phrases:

  1. Transplant operations [are carried out at specialist transplant units. They] are never split across more than one unit. An operation takes place at 1 Unit.

  2. Each unit is based at one hospital only A unit can only be in 1 hospital

  3. Specialises in one type of transplantation A unit has 1 specialisation

  4. A unit can transplant the other types of organ which lie outside of its area of expertise. A unit does not specifically have to transplant it's specialisation

  5. Some hospitals host more than one transplant unit. However some do not have a transplant unit. A hospital can have 0, 1 or many transplant units.

  • Transplant Operation:
    • Involves a Donor [1:1] and a Patient [1:1].
      • Encompasses one or more Organs [1:M].
  • Donor:
    • May be associated with one or more Transplant Operations [1:M].
  • Patient:
    • May be associated with one or more Transplant Operations [1:M].
  • Organ:
    • Is involved in one or more Transplant Operations [M:1].
  • Specialist Transplant Unit:
    • Is tied to one Hospital [1:1].
    • Specialises in one type of Organ transplantation [o:1].
    • Can handle other types of Organ transplants outside its specialization [o:M].
  • Hospital:
    • Can host one or more Specialist Transplant Units [1:M].
    • Not all hospitals have a Transplant Unit [o:1].

Hospital -|---o-< TransplantUnit

  • One hospital can have 0, 1 or many Units.
  • A unit must have a hospital, and only 1.