[Solved]-Django model – on_delete=models.PROTECT()

by

21👍

✅

Ignore your IDE. It is trying to get you to call the models.PROTECT function, which does indeed take those arguments. But you actually want to pass the function itself:

my_field = models.ForeignKey(..., on_delete=models.PROTECT)

ie without the parentheses that would call the function.

(Insert rant about using an IDE with a dynamic language here…)

👤Daniel Roseman

1👍

Import like:(Python 2.7)

from django.db.models.deletion import PROTECT

Then you can use it directly.

category = ForeignKey(TCategory, PROTECT, null=False, blank=False)
👤WesternGun

-1👍

models.PROTECT prevents deletions but does not raise an error by default.

you can create a custom exception for it, which is already protected.

from django.db import IntegrityError

class ModelIsProtectedError(IntegrityError):
    pass

def prevent_deletions(sender, instance, *args, **kwargs):
    raise ModelIsProtectedError("This model can not be deleted")


#in your models.py:
pre_delete.connect(prevent_deletions, sender=<your model>)
👤yet

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