Hello David, The proposed patch and test adjustments make sense to me, please open an associated ticket and PR.
Thanks for digging this through and working on a solution! I think that an argument could be made for the `if e.code == "unique" and len(constraint.fields) == 1` branch in `Model.validate_constraints` to be entirely encapsulated in `UniqueConstraint.validate` (which knows about len(self.fields)) but focusing on making sure the proper code is attributed to the ValidationError instance is definitely an improvement. Cheers, Simon Le mardi 13 septembre 2022 à 09:40:59 UTC-4, amolras...@gmail.com a écrit : > Then what I do..? > > On Mon, 12 Sep, 2022, 8:36 pm David Sanders, <shang.xia...@gmail.com> > wrote: > >> Hi Simon, >> >> > This should already work for constraints over a single field but not on >> the ones with multiple fields[0] which is covered by the suite[1] but it >> doesn't look like UniqueConstraint.validate is providing code="unique" >> which might be the source of the issue you are encountering? >> >> Yep that's correct. The code="unique" is only ever set from >> Model.unique_error_message() >> <https://github.com/django/django/blob/07ebef566f751e172e266165071081c7614e2d33/django/db/models/base.py#L1409> >> >> which, as you're already aware, is only called if there's no condition in >> UniqueConstraint.validate() >> <https://github.com/django/django/blob/07ebef566f751e172e266165071081c7614e2d33/django/db/models/constraints.py#L359>. >> >> Updating one of the tests confirms this (see below). >> >> Given that we'd like to avoid wording complications with conditions… >> looks like we could simply add code="unique" in UniqueConstraint.validate() >> as per: >> >> index 49c7c91de9..61ca15c7c4 100644 >> --- a/django/db/models/constraints.py >> +++ b/django/db/models/constraints.py >> @@ -364,6 +364,8 @@ class UniqueConstraint(BaseConstraint): >> if (self.condition & >> Exists(queryset.filter(self.condition))).check( >> against, using=using >> ): >> - raise >> ValidationError(self.get_violation_error_message()) >> + raise ValidationError( >> + message=self.get_violation_error_message(), >> code="unique" >> + ) >> except FieldError: >> pass >> >> Which then fixes the patched test: >> >> index d4054dfd77..d433555f9f 100644 >> --- a/tests/constraints/tests.py >> +++ b/tests/constraints/tests.py >> @@ -569,8 +569,9 @@ class UniqueConstraintTests(TestCase): >> name=obj1.name, color="blue" >> ).validate_constraints() >> msg = "Constraint “name_without_color_uniq” is violated." >> - with self.assertRaisesMessage(ValidationError, msg): >> + with self.assertRaisesMessage(ValidationError, msg) as cm: >> UniqueConstraintConditionProduct(name=obj2.name >> ).validate_constraints() >> + self.assertEqual(cm.exception.message_dict, {"name": [msg]}) >> >> def test_validate(self): >> constraint = UniqueConstraintProduct._meta.constraints[0] >> >> (pasting test failure) >> >> ====================================================================== >> FAIL: test_model_validation_with_condition >> (constraints.tests.UniqueConstraintTests) >> Partial unique constraints are not ignored by >> ---------------------------------------------------------------------- >> Traceback (most recent call last): >> ... >> AssertionError: {'__all__': ['Constraint “name_without_color_uniq” is >> violated.']} != {'name': ['Constraint “name_without_color_uniq” is >> violated.']} >> - {'__all__': ['Constraint “name_without_color_uniq” is violated.']} >> ? ^^ ^^^^ >> >> + {'name': ['Constraint “name_without_color_uniq” is violated.']} >> ? ^ ^^ >> >> >> If this is acceptable I could open a ticket / start a PR? >> >> -- >> David >> >> On Mon, 12 Sept 2022 at 23:26, charettes <chare...@gmail.com> wrote: >> >>> Hello David >>> >>> > Would it be possible to group the message by field in the same way as >>> standard unique? >>> >>> This should already work for constraints over a single field but not on >>> the ones with multiple fields[0] which is covered by the suite[1] but it >>> doesn't look like UniqueConstraint.validate is providing code="unique" >>> which might be the source of the issue you are encountering? >>> >>> [0] >>> https://github.com/django/django/blob/07ebef566f751e172e266165071081c7614e2d33/django/db/models/base.py#L1443-L1447 >>> [1] https://djangoci.com/job/django-coverage/HTML_20Coverage_20Report/ >>> >>> >>> Le dimanche 11 septembre 2022 à 22:02:35 UTC-4, shang.xia...@gmail.com >>> a écrit : >>> >>>> Hi Simon, >>>> >>>> Cheers for the explanation. >>>> >>>> I'm ok with the error message being the "constraint is violated" >>>> generic message as I agree with what you're saying. >>>> >>>> Would it be possible to group the message by field in the same way as >>>> standard unique? >>>> >>>> ie, would this be an idea?: >>>> >>>> django.core.exceptions.ValidationError: {'test': ['Constraint “unique” >>>> is violated.']} >>>> >>>> This way the customised error message would be preserved. >>>> >>>> This also leads to another question I had about whether it might be an >>>> idea to allow overriding error messages for constraints in forms using the >>>> error_messages dict… but I'll leave that for another post :) >>>> >>>> Regards, >>>> David >>>> >>>> On Mon, 12 Sept 2022 at 11:53, charettes <chare...@gmail.com> wrote: >>>> >>>>> Hello David, >>>>> >>>>> This is expected because Django doesn't have a way to express the >>>>> constraint in words to present to the user when a condition, which could >>>>> be >>>>> complex, is provided. >>>>> >>>>> When no conditions are defined the metadata is easy to interpret to >>>>> form a sentence out of ("Foo with this field0, field1, fieldN already >>>>> exists") while when a condition is provided Q can define very complex >>>>> criteria that only the developer is able to express in words. This is the >>>>> same class of problem as trying to have a machine describe a text >>>>> representation of a regular expression. It's doable for very simple cases >>>>> but almost impossible for complex ones. >>>>> >>>>> We decided not to try to be clever about what the error message should >>>>> be and opted to have a default that uses the constraint name when a >>>>> condition is present while allowing developers to provide a >>>>> `violation_error_message` at constraint initialization to have them >>>>> express >>>>> what a more appropriate error message should be. >>>>> >>>>> If we take your particular example, how should Django figure out what >>>>> the error message should be for a UniqueConstraint of this form? >>>>> >>>>> UniqueConstraint( >>>>> fields=["foo"], >>>>> name="unique_uppercase_foo", >>>>> condition=Q(test__upper=F("test")) >>>>> ) >>>>> >>>>> The developer who defined the constraint is in a much better position >>>>> to provide an error that says that "Test with an upper case "foo" must be >>>>> unique". If you're not convinced try with a complex condition involving >>>>> OR >>>>> and mixing transform comparison (e.g. a unique constraint only defined on >>>>> palindromes) >>>>> >>>>> Cheers, >>>>> Simon >>>>> >>>>> Le dimanche 11 septembre 2022 à 14:52:47 UTC-4, othnield...@gmail.com >>>>> a écrit : >>>>> >>>>>> nice one there >>>>>> >>>>>> On Sun, Sep 11, 2022 at 3:36 PM David Sanders <shang.xia...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> Hi folks (and in particular Simon Charette), >>>>>>> >>>>>>> I had a bit of a gotcha moment when a custom unique constraint >>>>>>> validation message disappeared when I added a condition to it. I won't >>>>>>> raise a ticket for this because it looks intentional from the >>>>>>> constraint >>>>>>> validation PR, but I wanted to seek clarification and whether either >>>>>>> some >>>>>>> adjustment to the behaviour could be made or clarification in the docs. >>>>>>> >>>>>>> Here's a boiled down example: >>>>>>> >>>>>>> Validating models with UniqueConstraint usually groups errors by >>>>>>> field name: >>>>>>> >>>>>>> class Test(Model): >>>>>>> test = CharField(max_length=255) >>>>>>> >>>>>>> class Meta: >>>>>>> constraints = [ >>>>>>> UniqueConstraint(fields=["test"], name="unique"), >>>>>>> ] >>>>>>> >>>>>>> Test.objects.create(test="abc") >>>>>>> test = Test(test="abc") >>>>>>> test.validate_constraints() >>>>>>> django.core.exceptions.ValidationError: {'test': ['Test with this >>>>>>> Test already exists.']} >>>>>>> >>>>>>> However if a condition is added to the UniqueConstraint the >>>>>>> validation error is categorised as a non-field error: >>>>>>> >>>>>>> class Test(Model): >>>>>>> test = CharField(max_length=255) >>>>>>> >>>>>>> class Meta: >>>>>>> constraints = [ >>>>>>> UniqueConstraint(fields=["test"], name="unique", >>>>>>> condition=~Q(test="")), >>>>>>> ] >>>>>>> >>>>>>> Test.objects.create(test="abc") >>>>>>> test = Test(test="abc") >>>>>>> test.validate_constraints() >>>>>>> django.core.exceptions.ValidationError: {'__all__': ['Constraint >>>>>>> “unique” is violated.']} >>>>>>> >>>>>>> This affects the way custom error messages are defined (eg forms >>>>>>> error_messages dict vs constraint violation_error_message) >>>>>>> >>>>>>> This behaviour is defined in UniqueConstraint.validate() and looks >>>>>>> to be intentional from this advice from Simon: >>>>>>> https://github.com/django/django/pull/14625#issuecomment-897275721 >>>>>>> >>>>>>> I was wondering what the rationale for that was? Would it be >>>>>>> possible to make the behaviour consistent? And if not - would a PR to >>>>>>> clarify how ValidationErrors are raised for constraints in the docs be >>>>>>> welcomed? >>>>>>> >>>>>>> Cheers, >>>>>>> David >>>>>>> >>>>>>> -- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "Django developers (Contributions to Django itself)" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to django-develop...@googlegroups.com. >>>>>>> To view this discussion on the web visit >>>>>>> https://groups.google.com/d/msgid/django-developers/CADyZw-5w94wvx26OVdSaDHGjKxRGvdnCZYeMOM-p4J9t9JUqMw%40mail.gmail.com >>>>>>> >>>>>>> <https://groups.google.com/d/msgid/django-developers/CADyZw-5w94wvx26OVdSaDHGjKxRGvdnCZYeMOM-p4J9t9JUqMw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Django developers (Contributions to Django itself)" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to django-develop...@googlegroups.com. >>>>> >>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/django-developers/455d67d0-ca3e-4bc2-888f-10312dae8915n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/django-developers/455d67d0-ca3e-4bc2-888f-10312dae8915n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Django developers (Contributions to Django itself)" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to django-develop...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-developers/d7130f45-9c78-4dfc-8a77-f49c98071fb2n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/django-developers/d7130f45-9c78-4dfc-8a77-f49c98071fb2n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django developers (Contributions to Django itself)" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to django-develop...@googlegroups.com. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-developers/CADyZw-4%2B3F9Nx%2BPVhNoh8Su5bvBky4O%2BBdOzmZT1MYxVaWDVrA%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/django-developers/CADyZw-4%2B3F9Nx%2BPVhNoh8Su5bvBky4O%2BBdOzmZT1MYxVaWDVrA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. 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