id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
27765	Migration to delete child model (multi-table inheritance) results in an error when using SQLite	Alexandru Mărășteanu	nobody	"1. Create two models where one of them inherits the other:
{{{
class Foo(models.Model):
    test = models.CharField(max_length=256)


class Bar(Foo):
    pass
}}}

2. Generate and run migrations.
`migrations/0001_initial.py` is:
{{{    
...
operations = [
    migrations.CreateModel(
        name='Foo',
        fields=[
            ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
            ('test', models.CharField(max_length=256)),
        ],
    ),
    migrations.CreateModel(
        name='Bar',
        fields=[
            ('foo_ptr', models.OneToOneField(auto_created=True, on_delete=django.db.models.deletion.CASCADE, parent_link=True, primary_key=True, serialize=False, to='foo.Foo')),
        ],
        bases=('foo.foo',),
    ),
]
...
}}}

3. Delete the child model (`Bar`)

4. Generate migrations
`migrations/0002_auto_20170123_1212.py` is:
{{{
...
operations = [
    migrations.RemoveField(
        model_name='bar',
        name='foo_ptr',
    ),
    migrations.DeleteModel(
        name='Bar',
    ),
]
...
}}}

5. Run migrations 
{{{
$ python manage.py migrate
Operations to perform:
  Apply all migrations: admin, contenttypes, foo, auth, sessions
Running migrations:
  Rendering model states... DONE
  Applying foo.0002_auto_20170123_1212...Traceback (most recent call last):
  File ""manage.py"", line 10, in <module>
    execute_from_command_line(sys.argv)
  File ""/djbug/lib/python2.7/site-packages/django/core/management/__init__.py"", line 353, in execute_from_command_line
    utility.execute()
  File ""/djbug/lib/python2.7/site-packages/django/core/management/__init__.py"", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File ""/djbug/lib/python2.7/site-packages/django/core/management/base.py"", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File ""/djbug/lib/python2.7/site-packages/django/core/management/base.py"", line 399, in execute
    output = self.handle(*args, **options)
  File ""/djbug/lib/python2.7/site-packages/django/core/management/commands/migrate.py"", line 200, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File ""/djbug/lib/python2.7/site-packages/django/db/migrations/executor.py"", line 92, in migrate
    self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
  File ""/djbug/lib/python2.7/site-packages/django/db/migrations/executor.py"", line 121, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File ""/djbug/lib/python2.7/site-packages/django/db/migrations/executor.py"", line 198, in apply_migration
    state = migration.apply(state, schema_editor)
  File ""/djbug/lib/python2.7/site-packages/django/db/migrations/migration.py"", line 123, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File ""/djbug/lib/python2.7/site-packages/django/db/migrations/operations/fields.py"", line 121, in database_forwards
    schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/sqlite3/schema.py"", line 247, in remove_field
    self._remake_table(model, delete_fields=[field])
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/sqlite3/schema.py"", line 197, in _remake_table
    self.quote_name(model._meta.db_table),
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/base/schema.py"", line 110, in execute
    cursor.execute(sql, params)
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/utils.py"", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/utils.py"", line 64, in execute
    return self.cursor.execute(sql, params)
  File ""/djbug/lib/python2.7/site-packages/django/db/utils.py"", line 95, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/utils.py"", line 64, in execute
    return self.cursor.execute(sql, params)
  File ""/djbug/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py"", line 323, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: near "")"": syntax error
}}}

Verified with Django (1.9.6 and 1.10.5) and SQLite 3 (sqlite3.version is 2.6.0) on macOS 10.12.2 with Python 2.7.12."	Bug	closed	Migrations	1.10	Normal	duplicate			Unreviewed	0	0	0	0	0	0