Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by João Paulo Limberger - JOTAPE - Shoo):

 Thanks! This workaround save my day Too!!!

 > Replying to [comment:7 Daniel Naab]:
 > > I hit this bug also, and worked around by:
 > >
 > > 1) Making the models `managed = True`
 > > 2) Running `manage.py makemigrations` for those models
 > > 3) Manually switched all `'managed': True` models in the migration to
 `'managed': False`
 > > 4) Switch models back to `managed = False`
 >
 > Same bug here and this workaround saved my day.
 > Thanks a lot!

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by Ponytech):

 Replying to [comment:7 Daniel Naab]:
 > I hit this bug also, and worked around by:
 >
 > 1) Making the models `managed = True`
 > 2) Running `manage.py makemigrations` for those models
 > 3) Manually switched all `'managed': True` models in the migration to
 `'managed': False`
 > 4) Switch models back to `managed = False`

 Same bug here and this workaround saved my day.
 Thanks a lot!

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+
Changes (by Fabio Sangiovanni):

 * cc: Fabio Sangiovanni (added)


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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by Simon Charette):

 Sergey,

 > Unmanaged models should not work in migrations by their nature.

 Is there a reason for that? How would the migration framework know how to
 generate references from managed models to unmanaged ones then (e.g. a
 foreign key)? The migration framework has supported managed model
 references for a while and even
 [https://docs.djangoproject.com/en/2.1/howto/writing-migrations/#changing-
 an-unmanaged-model-to-managed documents how to move an unmanaged model to
 a managed one].

 > You can make direct import of this model in migrations and use it.

 Direct model imports in migrations will break over time if the model
 definition happen to change and won't work when mixed up with
 state/migration models. The
 [https://docs.djangoproject.com/en/2.1/topics/migrations/#historical-
 models documentation warns about this pattern].

 I still believe this is a legitimate bug.

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by Sergey Yurchenko):

 Unmanaged models should not work in migrations by their nature.
 You can make direct import of this model in migrations and use it.
 I think it is expected behaviour not a bug.

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+
Changes (by Daniel Naab):

 * cc: Daniel Naab (added)


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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by Daniel Naab):

 I hit this bug also, and worked around by:

 1) Making the models `managed = True`
 2) Running `manage.py makemigrations` for those models
 3) Manually switched all `'managed': True` columns in the migration to
 `'managed': False`
 4) Switch models back to `managed = False`

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by Sven R. Kunze):

 Bug is also present on 1.11.

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+

Comment (by YBull):

 Using version 2.0.5, I just encountered this bug and when trying to work
 around it, discovered that it's a little more expansive than the example
 model with A, B, C above shows.  In my case, I had used the 'inspectdb'
 command to generate models for 12 legacy tables (all with managed =
 False).  The inspectdb command did a reasonably good job and included all
 the ForeignKey fields it should have.  But even after I commented out the
 lines in autodetector.py to work around this bug, I discovered that the
 'makemigrations' command still has another related problem with Fkeys on
 unmanaged models.  Specifically, whenever a new unmanaged model is
 referenced by another model's Fkeys, you must run 'makemigrations' for the
 referenced table BEFORE adding the model(s) containing the reference.  So
 in my case, even though the models.py was valid and complete at the
 beginning, I had to temporarily remove all the new dependent models to
 carefully generate a sequence of six separate migrations to get all my 12
 legacy tables in with the correct FKey declarations in the migration
 scripts.

 Being new to Django and the code base, I wanted to report this here, but
 I'm not sure whether the fix for this aspect is actually a separate
 related bug.

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  1 |  Needs documentation:  1
  Needs tests:  0 |  Patch needs improvement:  1
Easy pickings:  0 |UI/UX:  0
--+
Changes (by Keryn Knight):

 * needs_better_patch:  0 => 1
 * has_patch:  0 => 1
 * needs_docs:  0 => 1


Comment:

 WIP PR: https://github.com/django/django/pull/9741

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 Keywords:| Triage Stage:  Accepted
Has patch:  0 |  Needs documentation:  0
  Needs tests:  0 |  Patch needs improvement:  0
Easy pickings:  0 |UI/UX:  0
--+
Changes (by Simon Charette):

 * stage:  Unreviewed => Accepted


Comment:

 Seems like a legitimate bug.

 Do you think you could submit a PR with the removed lines and a test in
 
[https://github.com/django/django/blob/master/tests/migrations/test_autodetector.py
 test_autodetector.py] for it?

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Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+--
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 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 Keryn Knight:

Old description:

> Given models like the following, where `B` is unmanaged, and `C` is a
> normal concrete `Model`:
>
> {{{
> from django.db import models
>
> class A(models.Model):
> class Meta:
> db_table = "test_a"
>

> class B(models.Model):
> a = models.ForeignKey(A, related_name="+", on_delete=models.CASCADE)
>
> class Meta:
> managed = False
> db_table = "test_b"
>

> class C(models.Model):
> a = models.ForeignKey(A, related_name="+", on_delete=models.CASCADE)
>
> class Meta:
> db_table = "test_c"
> }}}
>
> when `python manage.py makemigrations ` is called, `B` ends up
> looking like:
> {{{
> migrations.CreateModel(
> name='B',
> fields=[
> ('id', models.AutoField(auto_created=True, primary_key=True,
> serialize=False, verbose_name='ID')),
> ],
> options={
> 'db_table': 'test_b',
> 'managed': False,
> },
> )
> }}}
> whilst `C` correctly gets:
> {{{
> migrations.CreateModel(
> name='C',
> fields=[
> ('id', models.AutoField(auto_created=True, primary_key=True,
> serialize=False, verbose_name='ID')),
> ('a',
> models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
> related_name='+', to='whee.A')),
> ],
> options={
> 'db_table': 'test_c',
> },
> )
> }}}
> Because `B` doesn't have the `a` attribute, any subsequent data
> migrations which would like to query on it, like so:
> {{{
> def forwards(apps, schema_editor):
> B = apps.get_model('whee', 'B')
> B.objects.filter(a=1)
> }}}
> will crash.
>
> With the assistance of Markus on IRC:
> {{{
> MarkusH: do you want to try what's gonna happen when you just drop the
> if-condition in
> https://github.com/django/django/blob/75527c0f8360ae3555fcf67ce19b4cb910b69b9d/django/db/migrations/autodetector.py#L570-L572
> ?
> }}}
>
> commenting out the lines
> {{{
> if not model_opts.managed:
> continue
> }}}
>
> allows the autodetector to generate the following:
> {{{
> migrations.CreateModel(
> name='A',
> fields=[
> ('id', models.AutoField(auto_created=True, primary_key=True,
> serialize=False, verbose_name='ID')),
> ],
> options={
> 'db_table': 'test_a',
> },
> ),
> migrations.AddField(
> model_name='b',
> name='a',
> field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
> related_name='+', to='whee.A'),
> )
> }}}
> and subsequently the data migration can access `B.a`
>
> If `A` itself is `managed=False` the migration generated is instead:
> {{{
> migrations.CreateModel(
> name='B',
> fields=[
> ('id', models.AutoField(auto_created=True, primary_key=True,
> serialize=False, verbose_name='ID')),
> ('a',
> models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
> related_name='+', to='whee.A')),
> ],
> options={
> 'db_table': 'test_b',
> 'managed': False,
> },
> )
> }}}
>
> Running the test suite via `./runtests.py` as of commit
> 75527c0f8360ae3555fcf67ce19b4cb910b69b9d doesn't seem to cause any
> failures, with those lines commented out.
>
> Markus also pointed out commit
> https://github.com/django/django/commit/215aa4f53b6bbd07d5c1eecfa94e7fcd00da813e
> which references #23415
>
> I noticed this "issue" while bringing a project up from 1.9, so it's not
> a recent problem.

New description:

 Given models like the following, where `B` is unmanaged, and `C` is a
 normal concrete `Model`:

 {{{
 from django.db import models

 class A(models.Model):
 class Meta:
 db_table = "test_a"


 class B(models.Model):
 a = models.ForeignKey(A, related_name="+", on_delete=models.CASCADE)

 class Meta:
 managed = False
 db_table = "test_b"


 class C(models.Model):
 a = models.ForeignKey(A, related_name="+", on_delete=models.CASCADE)

 class Meta:
 db_table = "test_c"
 }}}

 when `python manage.py makemigrations ` is called, `B` ends up
 looking like:
 {{{
 migrations.CreateModel(
 name='B',
 fields=[
 ('id', models.AutoField(auto_created=True, primary_key=True,
 serialize=False, verbose_name='ID')),
 ],
 options={
 'db_table': 

Re: [Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
--+--
 Reporter:  Keryn Knight  |Owner:  nobody
 Type:  Bug   |   Status:  new
Component:  Migrations|  Version:  master
 Severity:  Normal|   Resolution:
 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 Keryn Knight):

 * cc: Keryn Knight (added)


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[Django] #29177: Unmanaged models with ForeignKeys do not get those fields serialized into their migration state when CreateModel happens.

[Django]

#29177: Unmanaged models with ForeignKeys do not get those fields serialized 
into
their migration state when CreateModel happens.
+
   Reporter:  Keryn Knight  |  Owner:  nobody
   Type:  Bug   | Status:  new
  Component:  Migrations|Version:  master
   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 |
+
 Given models like the following, where `B` is unmanaged, and `C` is a
 normal concrete `Model`:

 {{{
 from django.db import models

 class A(models.Model):
 class Meta:
 db_table = "test_a"


 class B(models.Model):
 a = models.ForeignKey(A, related_name="+", on_delete=models.CASCADE)

 class Meta:
 managed = False
 db_table = "test_b"


 class C(models.Model):
 a = models.ForeignKey(A, related_name="+", on_delete=models.CASCADE)

 class Meta:
 db_table = "test_c"
 }}}

 when `python manage.py makemigrations ` is called, `B` ends up
 looking like:
 {{{
 migrations.CreateModel(
 name='B',
 fields=[
 ('id', models.AutoField(auto_created=True, primary_key=True,
 serialize=False, verbose_name='ID')),
 ],
 options={
 'db_table': 'test_b',
 'managed': False,
 },
 )
 }}}
 whilst `C` correctly gets:
 {{{
 migrations.CreateModel(
 name='C',
 fields=[
 ('id', models.AutoField(auto_created=True, primary_key=True,
 serialize=False, verbose_name='ID')),
 ('a',
 models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
 related_name='+', to='whee.A')),
 ],
 options={
 'db_table': 'test_c',
 },
 )
 }}}
 Because `B` doesn't have the `a` attribute, any subsequent data migrations
 which would like to query on it, like so:
 {{{
 def forwards(apps, schema_editor):
 B = apps.get_model('whee', 'B')
 B.objects.filter(a=1)
 }}}
 will crash.

 With the assistance of Markus on IRC:
 {{{
 MarkusH: do you want to try what's gonna happen when you just drop the if-
 condition in
 
https://github.com/django/django/blob/75527c0f8360ae3555fcf67ce19b4cb910b69b9d/django/db/migrations/autodetector.py#L570-L572
 ?
 }}}

 commenting out the lines
 {{{
 if not model_opts.managed:
 continue
 }}}

 allows the autodetector to generate the following:
 {{{
 migrations.CreateModel(
 name='A',
 fields=[
 ('id', models.AutoField(auto_created=True, primary_key=True,
 serialize=False, verbose_name='ID')),
 ],
 options={
 'db_table': 'test_a',
 },
 ),
 migrations.AddField(
 model_name='b',
 name='a',
 field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
 related_name='+', to='whee.A'),
 )
 }}}
 and subsequently the data migration can access `B.a`

 If `A` itself is `managed=False` the migration generated is instead:
 {{{
 migrations.CreateModel(
 name='B',
 fields=[
 ('id', models.AutoField(auto_created=True, primary_key=True,
 serialize=False, verbose_name='ID')),
 ('a',
 models.ForeignKey(on_delete=django.db.models.deletion.CASCADE,
 related_name='+', to='whee.A')),
 ],
 options={
 'db_table': 'test_b',
 'managed': False,
 },
 )
 }}}

 Running the test suite via `./runtests.py` as of commit
 75527c0f8360ae3555fcf67ce19b4cb910b69b9d doesn't seem to cause any
 failures, with those lines commented out.

 Markus also pointed out commit
 
https://github.com/django/django/commit/215aa4f53b6bbd07d5c1eecfa94e7fcd00da813e
 which references #23415

 I noticed this "issue" while bringing a project up from 1.9, so it's not a
 recent problem.

-- 
Ticket URL: 
Django 
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