#27274: KeyError when using RenameModel in migrations that refer to an unmanaged
model in another app.
-------------------------------+--------------------
Reporter: Dennis Ahrens | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.10
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------+--------------------
While upgrading from django 1.9 to django 1.10 i've encountered an
KeyError (see below) when running `python manage.py migrate`.
Inside of `RenameModel.state_forwards()` the ProjectState is not aware of
the unmanaged model included in another app and dies with the KeyError:
{{{
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/core/management/__init__.py", line 367, in
execute_from_command_line
utility.execute()
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/core/management/__init__.py", line 359, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/core/management/base.py", line 294, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/core/management/base.py", line 345, in execute
output = self.handle(*args, **options)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/core/management/commands/migrate.py", line 163, in
handle
pre_migrate_state =
executor._create_project_state(with_applied_migrations=True)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/db/migrations/executor.py", line 81, in
_create_project_state
migration.mutate_state(state, preserve=False)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/db/migrations/migration.py", line 92, in
mutate_state
operation.state_forwards(self.app_label, new_state)
File "/home/ahrensde/Projects/fk_to_unmanaged_model/venv/lib/python3.5
/site-packages/django/db/migrations/operations/models.py", line 323, in
state_forwards
for name, field in state.models[related_key].fields:
KeyError: ('legacy', 'legacymodel')
}}}
To reproduce the issue i've created a project containing two apps `legacy`
and `directed`; you can find the setup on github here:
https://github.com/dahrens/django_renamemodel_related_to_unmanaged_model
`legacy` does not use migrations at all and the models are unmanaged.
models.py might look like that:
{{{
from django.db import models
class LegacyModel(models.Model):
name = models.CharField(max_length=200)
class Meta:
managed = False
db_table = 'legacy_model'
}}}
The corresponding SQL statement to create the table like that:
{{{
CREATE table legacy_model (
id INTEGER PRIMARY KEY AUTOINCREMENT,
name character varying(50) NOT NULL
);
}}}
The direct app uses migrations and `models.py` that finally looks like
that:
{{{
from django.db import models
class RenamedDirectedModel(models.Model):
name = models.CharField(max_length=10)
legacy = models.ForeignKey("legacy.LegacyModel",
on_delete=models.CASCADE)
}}}
Additionally there are two migrations.
0001_initial.py:
{{{
# -*- coding: utf-8 -*-
# Generated by Django 1.9.9 on 2016-09-26 09:17
from __future__ import unicode_literals
from django.db import migrations, models
import django.db.models.deletion
class Migration(migrations.Migration):
initial = True
dependencies = [
('legacy', '__first__'),
]
operations = [
migrations.CreateModel(
name='DirectedModel',
fields=[
('id', models.AutoField(auto_created=True,
primary_key=True, serialize=False, verbose_name='ID')),
('name', models.CharField(max_length=10)),
('legacy',
models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
to='legacy.LegacyModel')),
],
),
]
}}}
and then 0002_auto_20160926_1023.py:
{{{
# -*- coding: utf-8 -*-
# Generated by Django 1.10.1 on 2016-09-26 10:23
from __future__ import unicode_literals
from django.db import migrations
class Migration(migrations.Migration):
dependencies = [
('directed', '0001_initial'),
]
operations = [
migrations.RenameModel(
old_name='DirectedModel',
new_name='RenamedDirectedModel',
),
]
}}}
Using the sample you can reproduce the bug with django version >= 1.10 -
everything below works fine. While debugging i tracked down, that the
issue is related to this commit:
https://github.com/django/django/commit/f1e408ff40d2c1753f92515c70a44634b4d47467
--
Ticket URL: <https://code.djangoproject.com/ticket/27274>
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