#36404: Aggregates with filter using OuterRef raise FieldError
-------------------------------------+-------------------------------------
Reporter: Adam | Owner: Adam Johnson
Johnson |
Type: Bug | Status: assigned
Component: Database | Version: dev
layer (models, ORM) |
Severity: Release | Keywords:
blocker |
Triage Stage: | Has patch: 1
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
While upgrading a client project to Django 5.2, I encountered some
`FieldError`s like:
{{{#!python
FieldError: Cannot resolve keyword 'isbn' into field. Choices are: book,
book_id, id, isbn_ref
}}}
The issue is reproduced with models:
{{{#!python
from django.db import models
class Book(models.Model):
isbn = models.IntegerField()
class Chapter(models.Model):
book = models.ForeignKey(Book, on_delete=models.CASCADE)
isbn_ref = models.IntegerField()
}}}
And `QuerySet`:
{{{#!python
from django.db.models import Count, OuterRef, Q, Subquery
from example.models import Book, Chapter
qs = Book.objects.annotate(
point_count=Subquery(
Chapter.objects.annotate(
count=Count(
"id",
filter=Q(isbn_ref=OuterRef("isbn")),
)
).values("count")
)
)
}}}
Full traceback:
{{{
$ python t.py
Traceback (most recent call last):
File "/.../t.py", line 14, in <module>
Chapter.objects.annotate(
~~~~~~~~~~~~~~~~~~~~~~~~^
count=Count(
^^^^^^^^^^^^
...<2 lines>...
)
^
).values("count")
^
File "/.../django/django/db/models/manager.py", line 87, in
manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/query.py", line 1643, in annotate
return self._annotate(args, kwargs, select=True)
~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/query.py", line 1695, in _annotate
clone.query.add_annotation(
~~~~~~~~~~~~~~~~~~~~~~~~~~^
annotation,
^^^^^^^^^^^
alias,
^^^^^^
select=select,
^^^^^^^^^^^^^^
)
^
File "/.../django/django/db/models/sql/query.py", line 1218, in
add_annotation
annotation = annotation.resolve_expression(self, allow_joins=True,
reuse=None)
File "/.../django/django/db/models/aggregates.py", line 271, in
resolve_expression
result = super().resolve_expression(*args, **kwargs)
File "/.../django/django/db/models/aggregates.py", line 124, in
resolve_expression
c.filter.resolve_expression(query, allow_joins, reuse, summarize)
~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/expressions.py", line 300, in
resolve_expression
expr.resolve_expression(query, allow_joins, reuse, summarize)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/sql/where.py", line 288, in
resolve_expression
clone._resolve_node(clone, *args, **kwargs)
~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/sql/where.py", line 280, in
_resolve_node
cls._resolve_node(child, query, *args, **kwargs)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/sql/where.py", line 284, in
_resolve_node
node.rhs = cls._resolve_leaf(node.rhs, query, *args, **kwargs)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/sql/where.py", line 273, in
_resolve_leaf
expr = expr.resolve_expression(query, *args, **kwargs)
File "/.../django/django/db/models/expressions.py", line 958, in
resolve_expression
col = super().resolve_expression(*args, **kwargs)
File "/.../django/django/db/models/expressions.py", line 902, in
resolve_expression
return query.resolve_ref(self.name, allow_joins, reuse, summarize)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../django/django/db/models/sql/query.py", line 2049, in
resolve_ref
join_info = self.setup_joins(
field_list, self.get_meta(), self.get_initial_alias(),
can_reuse=reuse
)
File "/.../django/django/db/models/sql/query.py", line 1900, in
setup_joins
path, final_field, targets, rest = self.names_to_path(
~~~~~~~~~~~~~~~~~~^
names[:pivot],
^^^^^^^^^^^^^^
...<2 lines>...
fail_on_missing=True,
^^^^^^^^^^^^^^^^^^^^^
)
^
File "/.../django/django/db/models/sql/query.py", line 1805, in
names_to_path
raise FieldError(
...<2 lines>...
)
django.core.exceptions.FieldError: Cannot resolve keyword 'isbn' into
field. Choices are: book, book_id, id, isbn_ref
}}}
The error occurs because the `isbn` field is looked up against the inner
model, `Chapter`, rather than the outer one, `Book`.
I bisected the error to e306687a3a5507d59365ba9bf545010e5fd4b2a8. That
commit referenced #36042 and was part of a PR for #36117. The
simplification left a duplicated call to `resolve_expression()` for
`Aggregate.filter`, leading to “over resolution” and triggering the
`FieldError`. The issue is similar to #36117, which removed some duplicate
`resolve_expression()` methods from `Case` and `When`.
While fixing this issue, I spotted the same mistake had been made for the
newly added `Aggregate.order_by` from #35444, which the PR associated to
this ticket fixes in a second commit. The first commit should be
backported to 5.2, the second left only on `main`.
--
Ticket URL: <https://code.djangoproject.com/ticket/36404>
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