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
36360	KeyError calling `update()` after an `annotate()` and a `values()`	Gav O'Connor	Simon Charette	"== Summary

We have noticed an issue when migrating from Django 5.1 to 5.2 in that we now get a `KeyError` where it previously worked without issue. I can't see anything in the changelog that would point towards this being an intended change.

The bug seems to happen when we try to call `.update()` on a QuerySet after we have called both `.annotate()` and `.values()` on it. A `KeyError` is raised with the name of the annotation.

Our real-world example is quite complex, but I have managed to simplify it somewhat in the example below. 

== Example


{{{#!python
# models.py
from django.db import models

class Service(models.Model):
    name = models.CharField(max_length=255)
    slug = models.SlugField(max_length=255)

    def __str__(self):
        return self.name

class Order(models.Model):
    service_slug = models.CharField(max_length=255)

    def __str__(self):
        return self.id

class OrderLine(models.Model):
    order = models.ForeignKey(Order, on_delete=models.CASCADE)
    notes = models.CharField(max_length=255, blank=True, null=True)

    def __str__(self):
        return self.id
}}}


{{{#!python
# tests.py
from django.test import TestCase
from django.db.models import OuterRef, Subquery
from .models import Service, Order, OrderLine

class MyTestCase(TestCase):
    def test_1(self):
        Service.objects.create(name=""Green"", slug=""green"")
        
        order = Order.objects.create(service_slug=""green"")
        OrderLine.objects.create(order=order)
        
        lines = OrderLine.objects.annotate(
            service=Subquery(
                Service.objects.filter(slug=OuterRef('order__service_slug')).values_list('name')[:1]
            )
        ).values(
            'id',
            'service',
        )
        
        lines.update(notes='foo')
}}}

== Output

=== Django 5.1

{{{
❯ uv add django==5.1
❯ uv run manage.py test
Found 1 test(s).
.
----------------------------------------------------------------------
Ran 1 test in 0.001s

OK
}}}

=== Django 5.2

{{{
❯ uv add django==5.2
❯ uv run manage.py test
Found 1 test(s).
E
======================================================================
ERROR: test_1 (core.tests.MyTestCase.test_1)
----------------------------------------------------------------------
Traceback (most recent call last):
  File ""/Users/gav/code/annotatebug/core/tests.py"", line 21, in test_1
    lines.update(notes='foo')
    ~~~~~~~~~~~~^^^^^^^^^^^^^
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/query.py"", line 1258, in update
    rows = query.get_compiler(self.db).execute_sql(ROW_COUNT)
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 2059, in execute_sql
    row_count = super().execute_sql(result_type)
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 1609, in execute_sql
    sql, params = self.as_sql()
                  ~~~~~~~~~~~^^
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 1988, in as_sql
    self.pre_sql_setup()
    ~~~~~~~~~~~~~~~~~~^^
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 2110, in pre_sql_setup
    super().pre_sql_setup()
    ~~~~~~~~~~~~~~~~~~~~~^^
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 85, in pre_sql_setup
    self.setup_query(with_col_aliases=with_col_aliases)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 74, in setup_query
    self.select, self.klass_info, self.annotation_col_map = self.get_select(
                                                            ~~~~~~~~~~~~~~~^
        with_col_aliases=with_col_aliases,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File ""/Users/gav/code/annotatebug/.venv/lib/python3.13/site-packages/django/db/models/sql/compiler.py"", line 283, in get_select
    expression = self.query.annotations[expression]
                 ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
KeyError: 'service'

----------------------------------------------------------------------
Ran 1 test in 0.003s

FAILED (errors=1)
}}}"	Bug	closed	Database layer (models, ORM)	5.2	Release blocker	fixed		Gav O'Connor	Ready for checkin	1	0	0	0	0	0