id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
34743	full_clean() raises AttributeError on constraints with related IDs.	NWAWEL A IROUME	Francesco Panico	"
{{{
from django.db import models
from django.db.models.constraints import CheckConstraint
from django.db.models import F, Q

# model with self FK
class Structure(models.Model):
    upper_structure = models.ForeignKey(
            ""self"",
            on_delete=models.SET_NULL,
            null=True,
            blank=True,
            related_name=""structures"",
        )

    class Meta:
            constraints = [
                # un poste ne peut pas etre lui-meme sont poste superieur
                CheckConstraint(
                    check=~Q(pk=F(""upper_structure__pk"")),
                    name=""%(app_label)s_%(class)s_upper_structure_not_equals_self"",
                )
            ]

# check the issue here
s = Structure()
s.full_clean()

}}}


**Expected behavior calling full_clean() shoul not trigger the error
**


{{{
#Here is the stack trace

File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/base.py"", line 1491, in full_clean
self.validate_constraints(exclude=exclude)
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/base.py"", line 1442, in validate_constraints
constraint.validate(model_class, self, exclude=exclude, using=using)
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/constraints.py"", line 92, in validate
if not Q(self.check).check(against, using=using):
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/query_utils.py"", line 134, in check
query.add_q(self)
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1532, in add_q
clause, _ = self._add_q(q_object, self.used_aliases)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1562, in _add_q
child_clause, needed_inner = self.build_filter(
                                ^^^^^^^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1388, in build_filter
return self._add_q(
        ^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1562, in _add_q
child_clause, needed_inner = self.build_filter(
                                ^^^^^^^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1407, in build_filter
lookups, parts, reffed_expression = self.solve_lookup_type(arg)
                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1217, in solve_lookup_type
_, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File ""/home/plexuserp/venv/lib/python3.11/site-packages/django/db/models/sql/query.py"", line 1656, in names_to_path
name = opts.pk.name
           ^^^^^^^
AttributeError: 'NoneType' object has no attribute 'pk'
}}}
"	Bug	closed	Database layer (models, ORM)	4.2	Normal	fixed	constraints, models, integrity	nwawelairoume14@… n.iroume@… wdmofor@… Gagaro	Ready for checkin	1	0	0	0	0	0