[Django] #30691: Change uuid field to FK does not create dependency
Django
-----------------------------------------+--------------------------
Reporter: Dart | Owner: nobody
Type: Bug | Status: new
Component: Uncategorized | Version: 2.2
Severity: Normal | Keywords: UUID, FK
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-----------------------------------------+--------------------------
Hi! I am new in django community, so please help me, because i really dont
know is it really "bug".
I have a django project named "testproject" and two apps: testapp1,
testapp2.
It will be simpler to understand, with this example:
# TestApp1(models.py):
class App1(models.Model):
id = models.UUIDField(primary_key=True, unique=True,
default=uuid.uuid4, editable=False, verbose_name=_('identifier'))
text = models.CharField(max_length=100, verbose_name=_('text'))
another_app = models.UUIDField(null=True, blank=True,
verbose_name=_('another app'))
# TestApp2(models.py):
class App2(models.Model):
id = models.UUIDField(primary_key=True, unique=True,
default=uuid.uuid4, editable=False, verbose_name=_('identifier'))
text = models.CharField(max_length=100, verbose_name=_('text'))
First model named "App1" has UUID field named "another_app":
- another_app = models.UUIDField(null=True, blank=True,
verbose_name=_('another app'))
After some time i change field from UUID to FK, like this:
- another_app = models.ForeignKey(App2, null=True, blank=True,
on_delete=models.SET_NULL, verbose_name=_('another app'))
And as result i create new migration, but Migration class was unexpected
result, because it does not create any "dependencies" for App2, because of
FK.
I think the correct solution will be create dependency for App2.
This project use django version 2.2 and postgresql. Attach archive with
sources. Project contains small test, after running him, you will get
exception like this: ValueError: Related model 'testapp2.App2' cannot be
resolved.
So is it problem in django or maybe i dont understand something ?
Here is my post in django users:
https://groups.google.com/forum/#!searchin/django-
users/Django$20bug$3A$20change$20uuid$20field$20to$20FK$20does$20not$20create$20dependency%7Csort:date
/django-users/-h9LZxFomLU/yz-NLi1cDgAJ
Regards, Viktor Lomakin
--
Ticket URL: <https://code.djangoproject.com/ticket/30691>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: Dart | Owner: nobody
Type: Bug | Status: new
Component: Uncategorized | Version: 2.2
Keywords: UUID, FK | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Dart):
* Attachment "testproject.zip" added.
Django project which show the bug
Django
Reporter: Dart | Owner: nobody
Type: Bug | Status: new
Severity: Normal | Resolution:
Keywords: UUID, FK | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Carlton Gibson):
* version: 2.2 => master
* component: Uncategorized => Migrations
* stage: Unreviewed => Accepted
Comment:
There's a lot of history in here, so it may turn out this is a duplicate,
but I'll accept this for now, as there's certainly a bug.
`makemigrations` generats this:
{{{
dependencies = [
('testapp1', '0002_app1_another_app'),
]
operations = [
migrations.AlterField(
model_name='app1',
name='another_app',
field=models.ForeignKey(blank=True, null=True,
on_delete=django.db.models.deletion.SET_NULL, to='testapp2.App2',
verbose_name='another app'),
),
]
}}}
But that gives the `ValueError` as you say.
Adjusting `dependencies` allows the test to pass:
{{{
dependencies = [
('testapp1', '0002_app1_another_app'),
('testapp2', '0001_initial'),
]
}}}
Thus, `AlterField` should pick this up.
(Note for later: SQLite raised will required disabling constraint
checking, ref #30023.)
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:1>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Dart):
* status: new => assigned
* owner: nobody => Dart
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:2>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Old description:
New description:
Hi! I am new in django community, so please help me, because i really dont
know is it really "bug".
I have a django project named "testproject" and two apps: testapp1,
testapp2.
It will be simpler to understand, with this example:
# TestApp1(models.py):
{{{#!python
class App1(models.Model):
id = models.UUIDField(primary_key=True, unique=True,
default=uuid.uuid4, editable=False, verbose_name=_('identifier'))
text = models.CharField(max_length=100, verbose_name=_('text'))
another_app = models.UUIDField(null=True, blank=True,
verbose_name=_('another app'))
}}}
# TestApp2(models.py):
{{{#!python
Regards, Viktor Lomakin
--
Comment (by Simon Charette):
That's probably a bug in
`django.db.migrations.autodetector.MigrationAutodetector.generate_altered_fields`'s
[https://github.com/django/django/blob/514efa3129792ec2abb2444f3e7aeb3f21a38386/django/db/migrations/autodetector.py#L966-L974
call to add_operation] which doesn't pass any `dependencies` when
`new_field.is_relation and not old_field.is_relation`. The dependencies
can be retrieved by using
`self._get_dependencies_for_foreign_key(new_field)`.
We want to depend on the latest migration of the referenced app instead of
the initial one though as the model we're referencing might have been
altered since then but that's something the aforementioned method should
handle.
Tests should be added to `django/tests/migrations/test_autodetector.py`.
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:3>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Simon Charette):
Hello Dart,
Are you still planing to work on this? Do you need any assistance
submitting a patch?
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:4>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Dmitrij Strelnikov):
I'm pretty sure your db change interfere with migration best practice.
You are changing field type, which have to be done in two steps.
And your migrations are not telling django what should be done with data
in uuid field contains when migrate.
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:5>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Dart):
Replying to [comment:4 Simon Charette]:
> Hello Dart,
>
> Are you still planing to work on this? Do you need any assistance
submitting a patch?
Yes i'm work with this patch and planning to send this. Yes, it will be
good, if you help me.
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:6>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Dart):
Replying to [comment:4 Simon Charette]:
> Hello Dart,
>
> Are you still planing to work on this? Do you need any assistance
submitting a patch?
Hi! Today i will send a patch. I found a problem and resolve it.
Regards
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:7>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Comment (by Dart):
Hi! Send pull request, please check it. And please can you help me where
to put docs.
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:8>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Dart):
* has_patch: 0 => 1
Comment:
https://github.com/django/django/pull/11740
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:9>
Django
Reporter: Dart | Owner: Dart
Type: Bug | Status: assigned
Component: Migrations | Version: master
Severity: Normal | Resolution:
Has patch: 1 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Simon Charette):
* stage: Accepted => Ready for checkin
Comment:
Hey Dart, thanks for submitting a PR!
Since this is a bug fix it shouldn't not require any docs. I've marked the
patch RFC since only trivial changes need to be made before the patch is
merged which is something committers can take care of.
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:10>
Django
Reporter: Dart | Owner: Dart
Component: Migrations | Version: master
Severity: Normal | Resolution: fixed
Keywords: UUID, FK | Triage Stage: Ready for checkin
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by Mariusz Felisiak <felisiak.mariusz@…>):
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"5931d2e96ae94b204d146b7f751e0e804da74953" 5931d2e9]:
{{{
#!CommitTicketReference repository=""
revision="5931d2e96ae94b204d146b7f751e0e804da74953"
Fixed #30691 -- Made migrations autodetector find dependencies for foreign
keys altering.
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/30691#comment:11>