dealing with foreign keys in Django-CodePudding

i am creating a doctor appointment system, and i did include prescriptions too

class Prescription(models.Model):
    id = models.UUIDField(default=uuid.uuid4, primary_key=True, editable=False)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    doctor = models.ForeignKey(Doctor, null = True, on_delete=models.SET_NULL)
    clinic = models.ForeignKey(Clinic, on_delete=models.SET_NULL)

i was thinking what if the doctor delete his account for some reasons, can the doctor or the clinic set to null if this happen?

CodePudding user response：

You can add doctor_name and clinic_name fields in your models.py:

class Prescription(models.Model):
    id = models.UUIDField(default=uuid.uuid4, primary_key=True, editable=False)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    doctor = models.ForeignKey(Doctor, null = True, on_delete=models.SET_NULL)
    clinic = models.ForeignKey(Clinic, on_delete=models.SET_NULL)

    doctor_name = models.CharField(max_length=100, blank=False)
    clinic_name = models.CharField(max_length=100, blank=False)

And add the doctor's name and the name of the clinic each time. However, this is very redundant....

Actually, here iss stackoverflow's database schema -> url.
As you can see, there's OwnerDisplayName so that posts still have author's name.