Opened 8 years ago

Last modified 8 years ago

#26564 closed Bug

Migration for renaming M2M field intermediate model causes exception — at Version 1

Reported by: MohammadJafar MashhadiEbrahim Owned by: nobody
Component: Migrations Version: 1.9
Severity: Normal Keywords:
Cc: Triage Stage: Accepted
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by MohammadJafar MashhadiEbrahim)

There was Models Service, Application and ServiceActivation. ServiceActivation is intermediate model between Service and Application. I renamed ServiceActivation to ServiceInstance and theses migrations were generated:

        migrations.RenameModel(
            old_name='ServiceActivation',
            new_name='ServiceInstance',
        ),
        migrations.AlterField(
            model_name='application',
            name='services',
            field=models.ManyToManyField(related_name='user_applications', through='core.ServiceInstance', to='core.Service'),
        ),

I moved two operations to two separate migration files, the second is dependent on the first to ensure that sequence of running is correct. RenameModel operation runs normally but AlterField does not. Stack trace is as the following:

$ python manage.py migrate
Operations to perform:
  Apply all migrations: core
Running migrations:
  Applying core.0008_renamed_service_activation_model_2...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/core/management/__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/raven/contrib/django/management/__init__.py", line 41, in new_execute
    return original_func(self, *args, **kwargs)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/core/management/base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/core/management/commands/migrate.py", line 200, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/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 "/home/mjafar/Documents/project/venv/lib/python3.4/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 "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/db/migrations/executor.py", line 198, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/db/migrations/migration.py", line 123, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/db/migrations/operations/fields.py", line 201, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "/home/mjafar/Documents/project/venv/lib/python3.4/site-packages/django/db/backends/base/schema.py", line 465, in alter_field
    old_field.remote_field.through._meta.auto_created and
AttributeError: 'str' object has no attribute '_meta'

I read the code in schema.py around the line number that exception occuress, hoping to find a workaround but unfortunately i couldn't. Updated to Django 1.9.5 but bug still exists.

Change History (1)

comment:1 by MohammadJafar MashhadiEbrahim, 8 years ago

Description: modified (diff)
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