#28542: migration that introduces uuid field is not reversible with unique=True
--------------------------------------+------------------------
Reporter: karyon | Owner: nobody
Type: Bug | Status: new
Component: Migrations | Version: 1.11
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
--------------------------------------+------------------------
sorry for the confusing title, couldn't think of a better one...
this migration here (from https://github.com/fsr-
itse/EvaP/pull/1002/files)
{{{
# -*- coding: utf-8 -*-
# Generated by Django 1.11.3 on 2017-07-03 18:31
from __future__ import unicode_literals
from django.db import migrations, models
import uuid
def fill_textanswer_uuid(apps, schema_editor):
db_alias = schema_editor.connection.alias
TextAnswer = apps.get_model('evaluation', 'TextAnswer')
for obj in TextAnswer.objects.using(db_alias).all():
obj.uuid = uuid.uuid4()
obj.save()
class Migration(migrations.Migration):
""" this migration changes a model from a auto-generated id field to a
uuid-primary key. """
dependencies = [
('evaluation', '0059_add_yes_no_questions'),
]
# Based on
# https://gist.github.com/smcoll/8bb867dc631433c01fd0
operations = [
migrations.AddField(
model_name='textanswer',
name='uuid',
field=models.UUIDField(null=True),
),
migrations.RunPython(fill_textanswer_uuid,
migrations.RunPython.noop),
migrations.AlterField(
model_name='textanswer',
name='uuid',
field=models.UUIDField(primary_key=False, default=uuid.uuid4,
serialize=False, editable=False), # add 'unique=True' here
),
migrations.RemoveField('TextAnswer', 'id'),
migrations.RenameField(
model_name='textanswer',
old_name='uuid',
new_name='id'
),
migrations.AlterField(
model_name='textanswer',
name='id',
field=models.UUIDField(primary_key=True, default=uuid.uuid4,
serialize=False, editable=False),
),
]
}}}
runs fine forwards and backwards.
adding unique=True in the line indicated above makes the backward
direction fail, although it should intuitively have little to no effect.
especially the error {{{multiple primary keys for table
"evaluation_textanswer" are not allowed}}} doesn't make much sense to me.
traceback:
{{{
Traceback (most recent call last):
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
psycopg2.ProgrammingError: multiple primary keys for table
"evaluation_textanswer" are not allowed
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 "/home/vagrant/.local/lib/python3.4/site-
packages/django/core/management/__init__.py", line 363, in
execute_from_command_line
utility.execute()
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/core/management/__init__.py", line 355, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/core/management/base.py", line 283, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/core/management/base.py", line 330, in execute
output = self.handle(*args, **options)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/core/management/commands/migrate.py", line 204, in handle
fake_initial=fake_initial,
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/migrations/executor.py", line 119, in migrate
state = self._migrate_all_backwards(plan, full_plan, fake=fake)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/migrations/executor.py", line 194, in
_migrate_all_backwards
self.unapply_migration(states[migration], migration, fake=fake)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/migrations/executor.py", line 264, in unapply_migration
state = migration.unapply(state, schema_editor)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/migrations/migration.py", line 178, in unapply
operation.database_backwards(self.app_label, schema_editor,
from_state, to_state)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/migrations/operations/fields.py", line 160, in
database_backwards
schema_editor.add_field(from_model,
to_model._meta.get_field(self.name))
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/backends/base/schema.py", line 429, in add_field
self.execute(sql, params)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/backends/base/schema.py", line 120, in execute
cursor.execute(sql, params)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/backends/utils.py", line 80, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File "/home/vagrant/.local/lib/python3.4/site-
packages/django/db/backends/utils.py", line 65, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: multiple primary keys for table
"evaluation_textanswer" are not allowed
}}}
console output including sql statements when running the migration
backwards without the unique=True: https://pastebin.com/gs2SaBjt
with unique=True: https://pastebin.com/QUebX0aa
check them out, the sql is vastly different. i haven't investigated
further what the problem is.
--
Ticket URL: <https://code.djangoproject.com/ticket/28542>
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 post to this group, send email to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/049.f666506b38bd8f9e1086d1309797fc20%40djangoproject.com.
For more options, visit https://groups.google.com/d/optout.
