[Django] #26208: Squashing migrations in which unique=True is added and then removed for Charfield cannot migrate backwards on Postgres
Django
Charfield cannot migrate backwards on Postgres
--------------------------+------------------------------------------------
Reporter: linuss | Owner: nobody
Type: Bug | Status: new
Component: | Version: 1.9
Migrations |
Severity: Normal | Keywords: migrations squash charfield unique
Triage Stage: | Has patch: 0
Unreviewed |
Easy pickings: 0 | UI/UX: 0
--------------------------+------------------------------------------------
This bug can be reproduced as follows:
* Create a model with a CharField with unique=True
* Create a migration
* Alter the model so that CharField is no longer unique
* Create a new migration
* Squash the two migrations
* Migrate forwards, and then backwards
Error output:
{{{
psycopg2.ProgrammingError: relation
"survey_respondent_email_b0f1dc87_like" already exists
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
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/core/management/__init__.py", line 353, in
execute_from_command_line
utility.execute()
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/core/management/__init__.py", line 345, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, **cmd_options)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/core/management/base.py", line 399, in execute
output = self.handle(*args, **options)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/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
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/migrations/executor.py", line 96, in migrate
self._migrate_all_backwards(plan, full_plan, fake=fake)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/migrations/executor.py", line 163, in
_migrate_all_backwards
self.unapply_migration(states[migration], migration, fake=fake)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/migrations/executor.py", line 218, in
unapply_migration
state = migration.unapply(state, schema_editor)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/migrations/migration.py", line 172, in unapply
operation.database_backwards(self.app_label, schema_editor,
from_state, to_state)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/migrations/operations/fields.py", line 206, in
database_backwards
self.database_forwards(app_label, schema_editor, from_state, to_state)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/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
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/backends/base/schema.py", line 482, in
alter_field
old_db_params, new_db_params, strict)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/backends/postgresql/schema.py", line 116, in
_alter_field
self.execute(like_index_statement)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/backends/base/schema.py", line 110, in execute
cursor.execute(sql, params)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/backends/utils.py", line 79, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/utils.py", line 95, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/utils/six.py", line 685, in reraise
raise value.with_traceback(tb)
File
"/var/lib/jenkins/shiningpanda/jobs/914dc536/virtualenvs/d41d8cd9/lib/python3.4
/site-packages/django/db/backends/utils.py", line 64, in execute
return self.cursor.execute(sql, params)
django.db.utils.ProgrammingError: relation
"survey_respondent_email_b0f1dc87_like" already exists
}}}
This issue was not present in version 1.9.0, but appeared in version 1.9.2
(or 1.9.1). Probably related to #26034
--
Ticket URL: <https://code.djangoproject.com/ticket/26208>
Django <https://code.djangoproject.com/>
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Django
Charfield cannot migrate backwards on Postgres
Reporter: linuss | Owner: nobody
Type: Bug | Status: new
Severity: Normal | Resolution:
Keywords: migrations squash | Triage Stage:
charfield unique | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
Changes (by timgraham):
* needs_better_patch: => 0
* needs_tests: => 0
* needs_docs: => 0
Comment:
I followed those steps but couldn't reproduce. Could list the exact
commands for each step to ensure I didn't misinterpret?
--
Ticket URL: <https://code.djangoproject.com/ticket/26208#comment:1>
Django
Charfield cannot migrate backwards on Postgres
Reporter: linuss | Owner: nobody
Type: Bug | Status: closed
Component: Migrations | Version: 1.9
Severity: Normal | Resolution: needsinfo
Keywords: migrations squash | Triage Stage:
charfield unique | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Changes (by timgraham):
* status: new => closed
* resolution: => needsinfo
--
Ticket URL: <https://code.djangoproject.com/ticket/26208#comment:2>