Opened 13 years ago
Closed 9 years ago
#17043 closed Bug (duplicate)
Model subclass field named the same as one of the parent model subclasses clashes
Reported by: | Simon Charette | Owned by: | nobody |
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Component: | Database layer (models, ORM) | Version: | 1.3 |
Severity: | Normal | Keywords: | |
Cc: | Triage Stage: | Accepted | |
Has patch: | no | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
The following model inheritance should raise a warning on model validation:
from django.db import models class A(models.Model): pass class B(A): pass class C(A): b = models.BooleanField() print A.b #<django.db.models.fields.related.SingleRelatedObjectDescriptor object at 0x1b08e10> print B.b #<django.db.models.fields.related.SingleRelatedObjectDescriptor object at 0x1b08e10> print C.b #<django.db.models.fields.related.SingleRelatedObjectDescriptor object at 0x1b08e10> C.objects.create(b=False) #ValueError: Cannot assign "False": "C.b" must be a "B" instance.
Took me some time before figuring out what was happening. Feel free to rename the ticket with a more descriptive title.
Is there a reason why the RelatedObjectDescriptor
is also added to the subclasses of A
and not only the parent model? Lets say I have a c = C
instance, theres no way c.b
might return something, only a = A
might do?
Change History (2)
comment:1 by , 13 years ago
Triage Stage: | Unreviewed → Accepted |
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comment:2 by , 9 years ago
Resolution: | → duplicate |
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Status: | new → closed |
Marking as duplicate of #14217.
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The
RelatedObjectDescriptor
is not added to the subclasses - subclasses simply inherit descriptors by Python's normal inheritiance mechanism. Fixing this might be infeasible.However, a validation warning ought to be possible, and accepting on that basis.