[Django] #21664: Migrations and "Multi-Table" Inheritance
Django
---------------------------------+-----------------------------------
Reporter: andrew.ngo@… | Owner:
Type: Bug | Status: new
Component: Migrations | Version: master
Severity: Release blocker | Keywords: migration inheritance
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
---------------------------------+-----------------------------------
== Summary ==
I'm not entirely familiar with the internal workings of "'''Synchronize
unmigrated apps:'''" but my (freshly created) app doesn't seem to appear
in the list of unmigrated apps. Maybe this is how it's supposed to work?
Anyway, when the time comes to create all the new models through the
"'''Apply all migrations:'''" portion, the migration mechanism chokes on
creating inherited models if it has just created the base model.
== Steps to Recreate ==
I create an app "digestive", add it to INSTALLED_APPS in settings.py, and
give it the following two models (one inheriting from the other).
{{{
# models.py
from django.db import models
class Liver(models.Model):
pass
class DiseasedLiver(Liver):
ttl = models.PositiveIntegerField()
}}}
Then I run ''syncdb''. It tells me that I should run ''makemigrations''.
{{{
Operations to perform:
Synchronize unmigrated apps: admin, contenttypes, auth, sessions
Apply all migrations: (none)
[...]
No migrations needed.
Your models have changes that are not yet reflected in a migration, and
so won't be applied.
Run 'manage.py makemigrations' to make new migrations, and then re-run
'manage.py migrate' to apply them.
}}}
I run ''makemigrations'', then ''migrate''. This is the migration file it
generates.
{{{
# 0001_initial.py
from django.db import models, migrations
class Migration(migrations.Migration):
dependencies = []
operations = [
migrations.CreateModel(
fields = [('id', models.AutoField(verbose_name='ID',
serialize=False, auto_created=True, primary_key=True),)],
bases = (models.Model,),
options = {},
name = 'Liver',
),
migrations.CreateModel(
fields = [('liver_ptr', ('ttl',
models.PositiveIntegerField(),)],
bases = ('digestive.liver',),
options = {},
name = 'DiseasedLiver',
),
]
}}}
I run syncdb again. This is the output.
{{{
Operations to perform:
Synchronize unmigrated apps: admin, contenttypes, auth, sessions
Apply all migrations: digestive
[...]
Running migrations:
Applying digestive.0001_initial...Traceback (most recent call last):
File "/django/db/backends/utils.py", line 61, in execute
return self.cursor.execute(sql, params)
File "/django/db/backends/sqlite3/base.py", line 489, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: duplicate column name: liver_ptr_id
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/django/core/management/__init__.py", line 423, in
execute_from_command_line
utility.execute()
File "/django/core/management/__init__.py", line 415, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/django/core/management/base.py", line 243, in run_from_argv
self.execute(*args, **options.__dict__)
File "/django/core/management/base.py", line 290, in execute
output = self.handle(*args, **options)
File "/django/core/management/base.py", line 429, in handle
return self.handle_noargs(**options)
File "/django/core/management/commands/syncdb.py", line 22, in
handle_noargs
call_command("migrate", **options)
File "/django/core/management/__init__.py", line 170, in call_command
return klass.execute(*args, **defaults)
File "/django/core/management/base.py", line 290, in execute
output = self.handle(*args, **options)
File "/django/core/management/commands/migrate.py", line 145, in handle
executor.migrate(targets, plan, fake=options.get("fake", False))
File "/django/db/migrations/executor.py", line 60, in migrate
self.apply_migration(migration, fake=fake)
File "/django/db/migrations/executor.py", line 94, in apply_migration
migration.apply(project_state, schema_editor)
File "/django/db/migrations/migration.py", line 97, in apply
operation.database_forwards(self.app_label, schema_editor,
project_state, new_state)
File "/django/db/migrations/operations/models.py", line 26, in
database_forwards
schema_editor.create_model(model)
File "/django/db/backends/schema.py", line 233, in create_model
self.execute(sql, params)
File "/django/db/backends/schema.py", line 95, in execute
cursor.execute(sql, params)
File "/django/db/backends/utils.py", line 77, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/django/db/backends/utils.py", line 61, in execute
return self.cursor.execute(sql, params)
File "/django/db/utils.py", line 93, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/django/utils/six.py", line 495, in reraise
raise value.with_traceback(tb)
File "/django/db/backends/utils.py", line 61, in execute
return self.cursor.execute(sql, params)
File "/django/db/backends/sqlite3/base.py", line 489, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: duplicate column name: liver_ptr_id
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/21664>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
Reporter: andrew.ngo@… | Owner:
Type: Bug | Status: new
Component: Migrations | Version: master
Keywords: migration | Triage Stage:
inheritance | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by andrew.ngo@…):
* needs_better_patch: => 0
* severity: Release blocker => Normal
* needs_tests: => 0
* needs_docs: => 0
Comment:
Workaround: comment out submodels, run makemigrations, uncomment
submodels, run makemigrations again. (Then syncdb/migrate).
--
Ticket URL: <https://code.djangoproject.com/ticket/21664#comment:1>
Django
Reporter: andrew.ngo@… | Owner:
Type: Bug | andrewgodwin
Component: Migrations | Status: assigned
Severity: Normal | Version: master
Keywords: migration | Resolution:
inheritance | Triage Stage:
Has patch: 0 | Unreviewed
Needs tests: 0 | Needs documentation: 0
Easy pickings: 0 | Patch needs improvement: 0
| UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by andrewgodwin):
* owner: => andrewgodwin
* status: new => assigned
--
Ticket URL: <https://code.djangoproject.com/ticket/21664#comment:2>
Django
Reporter: andrew.ngo@… | Owner:
Type: Bug | andrewgodwin
Component: Migrations | Status: closed
Severity: Normal | Version: master
Keywords: migration | Resolution: fixed
inheritance | Triage Stage:
Has patch: 0 | Unreviewed
Needs tests: 0 | Needs documentation: 0
Easy pickings: 0 | Patch needs improvement: 0
| UI/UX: 0
-------------------------------------+-------------------------------------
* status: assigned => closed
* resolution: => fixed
Comment:
In [changeset:"3f1a008266e8797ae104905b4d3168fa2a33b9ae"]:
{{{
#!CommitTicketReference repository=""
revision="3f1a008266e8797ae104905b4d3168fa2a33b9ae"
Fixed #21664: Multi-table inheritance was duplicating _ptr fields
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/21664#comment:3>