#20742: ModelForm primary_key update with instance set is executed as INSERT
caused
by is_valid() chaning the instance
-------------------------------------+-------------------------------------
Reporter: amin@… | Owner: nobody
Type: Bug | Status: new
Component: Database layer | Version: 1.5
(models, ORM) | Keywords: modelform instance
Severity: Normal | primary_key update
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
I do agree this is a bad database design but it's executed without any
warning or anything in the docs so i want to open this ticket to allow the
discussion of raising an Error or anything (e.g. an info in the docs
@primary_key or modelform) not let anyone run into this mistake.
class Test(models.Model):
email = models.CharField(max_length=100, primary_key=True)
class TestForm(forms.ModelForm):
class Meta:
model = Test
# assuming this object exists
x = Test.objects.get(email='o...@example.com')
form = TestForm(email='n...@example.com', instance=x)
# here instance is updated with n...@example.com as pkey and django thinks
it has to create a new model instance not updating the old instance
if form.is_valid():
new_x = form.save()
new_x.save()
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Ticket URL: <https://code.djangoproject.com/ticket/20742>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
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