#35813: Makemigrations not properly tracking changes to unmanaged models
-------------------------------------+-------------------------------------
Reporter: Hanny G | Type: Bug
Status: new | Component:
| Migrations
Version: 5.1 | Severity: Normal
Keywords: makemigrations, | Triage Stage:
unmanaged | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
I believe there is a bug with the `makemigrations` command.
**The Issue/Bug:** Changes to unmanaged models are not being recognized by
`makemigrations`. If those same changes are applied to a managed model,
`makemigrations` recognizes the changes.
The `makemigrations` command tracks the Creation of an unmanaged model,
the Deletion of an unmanaged model, but does not track changes to the
attributes/fields of an unmanaged model (see example below for more
depth).
**Concerns/Discussion:** If you create an unmanaged model, make the
initial migration and then have to change a field on it, `makemigrations`
will not detect the change you made. At that point, your migrations (the
'historical reference') are out of sync with the current reality of the
model.
I have an if this is unclear.
For this example let's assume we have two models: `UnmanagedThing` and
`ManagedThing` (unmanaged and managed, respectively)
{{{
class UnmanagedThing(models.Model):
"""
This model represents an unmanaged Thing.
"""
id = models.IntegerField(
db_column="thingID", primary_key=True
)
thing_number = models.CharField(max_length=16,
db_column="thingNumber")
thing_name = models.CharField(max_length=50, db_column="thingName")
grade_level = models.CharField(max_length=2, db_column="gradeLevel")
class Meta:
"""Meta options for the UnmanagedThing model."""
verbose_name = "Unmanaged Thing"
verbose_name_plural = "Unmanaged Things"
managed = False
db_table = "some_table_name"
def __str__(self) -> str:
"""Return the course name."""
return f"{self.thing_name}"
class ManagedThing(models.Model):
"""
This model represents an unmanaged Thing.
"""
id = models.IntegerField(
db_column="thingID", primary_key=True
)
thing_number = models.CharField(max_length=16,
db_column="thingNumber")
thing_name = models.CharField(max_length=50, db_column="thingName")
grade_level = models.CharField(max_length=2, db_column="gradeLevel")
class Meta:
"""Meta options for the UnmanagedThing model."""
verbose_name = "Unmanaged Thing"
verbose_name_plural = "Unmanaged Things"
def __str__(self) -> str:
"""Return the course name."""
return f"{self.thing_name}"
}}}
If I run `makemigrations` I get the expected `0001...` migration file and
I see both models created with their respective fields/options.
If I change `thing_name` to be an `IntegerField` on the managed model and
run `makemigrations`, I see a `0002...` migration file created with the
expected 'AlterField' inside of it.
If I change `thing_name` to be an `IntegerField` on the unmanaged model
and run `makemigrations`, I see "No changes detected" and nothing is
created. However, now there is a disconnect between my model and what is
recorded in migrations.
Everything else works similarly between the two; if I delete either one,
it's recorded in a migration file. If I change the unmanaged model to
'managed', it creates a migration file for that (and subsequently begins
tracking changes as expected with `makemigrations`)
Per the django docs: " You should think of migrations as a version control
system for your database schema. `makemigrations` is responsible for
packaging up your model changes into individual migration files -
analogous to commits"; it's not behaving that way currently, so I believe
this to be a valid bug worth fixing if the docs
--
Ticket URL: <https://code.djangoproject.com/ticket/35813>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/0107019257b6f486-960590ba-7c98-4858-ba58-77adf3956b27-000000%40eu-central-1.amazonses.com.
