Opened 4 years ago

Last modified 4 years ago

#32457 closed Bug

SeparateDatabaseAndState fails with RemoveField — at Version 1

Reported by: Christian Bundy Owned by: nobody
Component: Migrations Version: 3.1
Severity: Normal Keywords: database state remove field
Cc: Triage Stage: Unreviewed
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by Christian Bundy)

Hi. We're doing multi-stage migrations with a blue-green deployment model, and currently bumping into an error. I think this is a small problem with a quick fix. The goal was to remove a field with three separate changes:

  1. Remove the model and create a migration that removes the field from Django's state.
  2. Create a migration that removes the field from the database.

I've reproduced the error in a Git repository here, with the above migrations:

​https://github.com/christianbundy/django-bug-remove-field/tree/main/example/migrations

Expected behavior: The migration succeeds.

Action behavior:

  File "/usr/local/lib/python3.9/site-packages/django/db/migrations/operations/fields.py", line 158, in state_forwards
    old_field = model_state.fields.pop(self.name)
KeyError: 'last_name'

Relevant Django code: ​https://github.com/django/django/blob/d02d60eb0f032c9395199fb73c6cd29ee9bb2646/django/db/migrations/operations/fields.py#L162

Is there some other way that I should be making this change, or is this a bug in Django?

Thanks for the help!

Change History (1)

comment:1 by Christian Bundy, 4 years ago

Description: modified (diff)
Note: See TracTickets for help on using tickets.
Back to Top