#34291: UniqueConstraint with expression including "desc()" causes admin to
crash
on adding an object
-------------------------------------+-------------------------------------
Reporter: Dan F | Owner: nobody
Type: Bug | Status: new
Component: Database | Version: 4.1
layer (models, ORM) |
Severity: Normal | Keywords:
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
I added this model:
{{{
class Foo(models.Model):
name = models.CharField(max_length=300, unique=True)
class Meta:
constraints = [
UniqueConstraint(
Lower("name").desc(), name="unique_lower_name"
)
]
}}}
and this admin class:
{{{
@admin.register(Foo)
class FooAdmin(admin.ModelAdmin):
search_fields = ("name",)
}}}
I based the UniqueConstraint on the documentation
(https://docs.djangoproject.com/en/4.1/ref/models/constraints/#django.db.models.UniqueConstraint.expressions),
which shows
{{{
UniqueConstraint(Lower('name').desc(), 'category',
name='unique_lower_name_category')
}}}
When I visit the admin and click "add foo", enter name "foo1", and click
Save, I get a stack trace:
{{{
Request Method: POST
Request URL: http://localhost:8000/admin/myapp/foo/add/
Django Version: 4.1.5
Python Version: 3.10.9
...
Traceback (most recent call last):
File ".../lib/python3.10/site-packages/django/db/backends/utils.py",
line 89, in _execute
return self.cursor.execute(sql, params)
The above exception (syntax error at or near "DESC"
LINE 1: ...werapp_foo" WHERE LOWER("myapp_foo"."name") DESC = (LO...
^
) was the direct cause of the following exception:
File ".../lib/python3.10/site-
packages/django/core/handlers/exception.py", line 55, in inner
response = get_response(request)
File ".../lib/python3.10/site-packages/django/core/handlers/base.py",
line 197, in _get_response
response = wrapped_callback(request, *callback_args,
**callback_kwargs)
File ".../lib/python3.10/site-packages/django/contrib/admin/options.py",
line 686, in wrapper
return self.admin_site.admin_view(view)(*args, **kwargs)
File ".../lib/python3.10/site-packages/django/utils/decorators.py", line
133, in _wrapped_view
response = view_func(request, *args, **kwargs)
File ".../lib/python3.10/site-
packages/django/views/decorators/cache.py", line 62, in _wrapped_view_func
response = view_func(request, *args, **kwargs)
File ".../lib/python3.10/site-packages/django/contrib/admin/sites.py",
line 242, in inner
return view(request, *args, **kwargs)
File ".../lib/python3.10/site-packages/django/contrib/admin/options.py",
line 1890, in add_view
return self.changeform_view(request, None, form_url, extra_context)
File ".../lib/python3.10/site-packages/django/utils/decorators.py", line
46, in _wrapper
return bound_method(*args, **kwargs)
File ".../lib/python3.10/site-packages/django/utils/decorators.py", line
133, in _wrapped_view
response = view_func(request, *args, **kwargs)
File ".../lib/python3.10/site-packages/django/contrib/admin/options.py",
line 1750, in changeform_view
return self._changeform_view(request, object_id, form_url,
extra_context)
File ".../lib/python3.10/site-packages/django/contrib/admin/options.py",
line 1796, in _changeform_view
form_validated = form.is_valid()
File ".../lib/python3.10/site-packages/django/forms/forms.py", line 205,
in is_valid
return self.is_bound and not self.errors
File ".../lib/python3.10/site-packages/django/forms/forms.py", line 200,
in errors
self.full_clean()
File ".../lib/python3.10/site-packages/django/forms/forms.py", line 439,
in full_clean
self._post_clean()
File ".../lib/python3.10/site-packages/django/forms/models.py", line
492, in _post_clean
self.instance.full_clean(exclude=exclude, validate_unique=False)
File ".../lib/python3.10/site-packages/django/db/models/base.py", line
1472, in full_clean
self.validate_constraints(exclude=exclude)
File ".../lib/python3.10/site-packages/django/db/models/base.py", line
1423, in validate_constraints
constraint.validate(model_class, self, exclude=exclude, using=using)
File ".../lib/python3.10/site-packages/django/db/models/constraints.py",
line 347, in validate
if queryset.exists():
File ".../lib/python3.10/site-packages/django/db/models/query.py", line
1226, in exists
return self.query.has_results(using=self.db)
File ".../lib/python3.10/site-packages/django/db/models/sql/query.py",
line 592, in has_results
return compiler.has_results()
File ".../lib/python3.10/site-
packages/django/db/models/sql/compiler.py", line 1366, in has_results
return bool(self.execute_sql(SINGLE))
File ".../lib/python3.10/site-
packages/django/db/models/sql/compiler.py", line 1398, in execute_sql
cursor.execute(sql, params)
File ".../lib/python3.10/site-
packages/debug_toolbar/panels/sql/tracking.py", line 230, in execute
return self._record(self.cursor.execute, sql, params)
File ".../lib/python3.10/site-
packages/debug_toolbar/panels/sql/tracking.py", line 154, in _record
return method(sql, params)
File ".../lib/python3.10/site-packages/django/db/backends/utils.py",
line 103, in execute
return super().execute(sql, params)
File ".../lib/python3.10/site-packages/django/db/backends/utils.py",
line 67, in execute
return self._execute_with_wrappers(
File ".../lib/python3.10/site-packages/django/db/backends/utils.py",
line 80, in _execute_with_wrappers
return executor(sql, params, many, context)
File ".../lib/python3.10/site-packages/django/db/backends/utils.py",
line 84, in _execute
with self.db.wrap_database_errors:
File ".../lib/python3.10/site-packages/django/db/utils.py", line 91, in
__exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File ".../lib/python3.10/site-packages/django/db/backends/utils.py",
line 89, in _execute
return self.cursor.execute(sql, params)
Exception Type: ProgrammingError at /admin/myapp/foo/add/
Exception Value: syntax error at or near "DESC"
LINE 1: ...myapp_foo" WHERE LOWER("myapp_foo"."name") DESC = (LO...
^
}}}
This happens on the Postgres backend (psycopg2 2.9.5).
I also get this error using the sqlite backend.
{{{
Exception Type: OperationalError at /admin/myapp/foo/add/
Exception Value: near "DESC": syntax error
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/34291>
Django <https://code.djangoproject.com/>
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