[Django] #22875: "ValueError: Lookup failed for model referenced by field app.Model.m2mfield: app.ThroghModel" in simple-self contained M2M setup
Django
app.Model.m2mfield: app.ThroghModel" in simple-self contained M2M setup
--------------------------------------+----------------------------
Reporter: ramiro | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.7-beta-2
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
--------------------------------------+----------------------------
In a simple `ManyToManyField` with intermediate model setup involving
three models in the same application:
{{{
# app_b/models.py
from django.db import models
class Employee(models.Model):
name = models.CharField(max_length=30)
class Employer(models.Model):
name = models.CharField(max_length=30)
employees = models.ManyToManyField(Employee, through='Employment')
class Employment(models.Model):
employee = models.ForeignKey(Employee)
employer = models.ForeignKey(Employer)
recruiting_date = models.DateField()
}}}
I'm seeing the following traceback when running `migrate` after the
initial migration has been created for the app:
{{{
~/dtest/dtest002$ rm -rf db.sqlite3 app_b/migrations
~/dtest/dtest002$ PYTHONPATH=~/django/upstream python ./manage.py
makemigrations
No changes detected
ramiro@serverid:~/dtest/dtest002$ PYTHONPATH=~/django/upstream python
./manage.py makemigrations app_b
Migrations for 'app_b':
0001_initial.py:
- Create model Employee
- Create model Employer
- Create model Employment
~/dtest/dtest002$ PYTHONPATH=~/django/upstream python ./manage.py migrate
Operations to perform:
Synchronize unmigrated apps: (none)
Apply all migrations: admin, contenttypes, app_b, auth, sessions
Synchronizing apps without migrations:
Creating tables...
Installing custom SQL...
Installing indexes...
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying app_b.0001_initial...Traceback (most recent call last):
File "./manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/home/xxx/django/upstream/django/core/management/__init__.py",
line 385, in execute_from_command_line
utility.execute()
File "/home/xxx/django/upstream/django/core/management/__init__.py",
line 377, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/xxx/django/upstream/django/core/management/base.py", line
288, in run_from_argv
self.execute(*args, **options.__dict__)
File "/home/xxx/django/upstream/django/core/management/base.py", line
337, in execute
output = self.handle(*args, **options)
File
"/home/xxx/django/upstream/django/core/management/commands/migrate.py",
line 146, in handle
executor.migrate(targets, plan, fake=options.get("fake", False))
File "/home/xxx/django/upstream/django/db/migrations/executor.py", line
62, in migrate
self.apply_migration(migration, fake=fake)
File "/home/xxx/django/upstream/django/db/migrations/executor.py", line
96, in apply_migration
migration.apply(project_state, schema_editor)
File "/home/xxx/django/upstream/django/db/migrations/migration.py", line
107, in apply
operation.database_forwards(self.app_label, schema_editor,
project_state, new_state)
File
"/home/xxx/django/upstream/django/db/migrations/operations/models.py",
line 33, in database_forwards
apps = to_state.render()
File "/home/xxx/django/upstream/django/db/migrations/state.py", line 89,
in render
model=lookup_model,
ValueError: Lookup failed for model referenced by field
app_b.Employer.employees: app_b.Employment
}}}
I'm selecting '1.7/beta-2' as Version but I'm running the latest
`stable/1.7.x` code:
{{{
~/django/upstream$ git log -1
commit 30d8b95139a1fa3070f3b112115e624ffcf8e555
Author: Tim Graham <timog...@gmail.com>
Date: Thu Jun 19 11:02:53 2014 -0400
[1.7.x] Added feature for implied null (needed for Firebird backend)
Backport of 1b07781292 from master
}}}
Initially Employee didn't exist and the m2m relationship was against a
custom User model.
After that trying to create a minimal setup that reproduces the issue,
usage of the swappable user model feature was removed and the m2m field
was re-pointed to standard auth.User, and finally to a local Employee
model.
--
Ticket URL: <https://code.djangoproject.com/ticket/22875>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
app.Model.m2mfield: app.ThroghModel" in simple-self contained M2M setup
Reporter: ramiro | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.7-beta-2
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Description changed by ramiro:
Old description:
New description:
After that (and when trying to create a minimal setup that reproduces the
issue):
- First usage of the swappable user model feature was removed and the m2m
field was re-pointed to standard auth.User
- And finally to a local Employee model.
In all cases, the same exception was generated.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/22875#comment:1>
Django
app.Model.m2mfield: app.ThroghModel" in simple-self contained M2M setup
Reporter: ramiro | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.7-beta-2
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by ramiro):
* severity: Normal => Release blocker
Comment:
This didn't fail in 1.7b4. `git bisect` between 1.7b4 and current 1.7 code
shows this is a regression introduced in:
{{{
commit 31fc34e447137631e6ea58fc33f3642e65479472
Date: Thu Jun 5 23:03:33 2014 -0700
[1.7.x] Rewrote migration autodetector to involve actual computer
science.
Fixes #22605, #22735; also lays the ground for some other fixes.
Conflicts:
django/db/migrations/autodetector.py
}}}
Marking as release blocker.
--
Ticket URL: <https://code.djangoproject.com/ticket/22875#comment:2>
Django
app.Model.m2mfield: app.ThroghModel" in simple-self contained M2M setup
Reporter: ramiro | Owner: nobody
Type: Bug | Status: closed
Component: Migrations | Version: 1.7-beta-2
Severity: Release blocker | Resolution: fixed
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Andrew Godwin <andrew@…>):
* status: new => closed
* resolution: => fixed
Comment:
In [changeset:"aa0886e7ae1f372488210e4e51ee6901af8ec643"]:
{{{
#!CommitTicketReference repository=""
revision="aa0886e7ae1f372488210e4e51ee6901af8ec643"
[1.7.x] Fixed #22875: Optimizer did not take through= into account.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/22875#comment:3>
Django
app.Model.m2mfield: app.ThroghModel" in simple-self contained M2M setup
Reporter: Ramiro Morales | Owner: nobody
Type: Bug | Status: closed
Component: Migrations | Version: 1.7-beta-2
Severity: Release blocker | Resolution: fixed
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Tim Graham <timograham@…>):
In [changeset:"e4c0878b30cf1fc29212185c55614fc463393af1" e4c0878b]:
{{{
#!CommitTicketReference repository=""
revision="e4c0878b30cf1fc29212185c55614fc463393af1"
Refs #22875 -- Fixed an optimizer test to use a valid scenario.
An explicit intermediary many-to-many relationship must declare forward
and
reverse foreign keys. The original issue was in the autodetector as these
operations shouldn't have been generated in this order in the first place
which is tested by AutodetectorTests.test_create_with_through_model.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/22875#comment:4>