Flushing a Database in Django - django

Question

I'm setting up a database in django, while trying to flush the database i get the following error:
You have requested a flush of the database.
This will IRREVERSIBLY DESTROY all data currently in the "/home/luc/projects/PySorge/API/db.sqlite3" database,
and return each table to an empty state.
Are you sure you want to do this?
Type yes to continue, or no to cancel: yes
Traceback (most recent call last):
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 413, in execute
return Database.Cursor.execute(self, query, params)
sqlite3.IntegrityError: NOT NULL constraint failed: django_content_type.name
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/luc/projects/PySorge/API/manage.py", line 22, in <module>
main()
File "/home/luc/projects/PySorge/API/manage.py", line 18, in main
execute_from_command_line(sys.argv)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
utility.execute()
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/__init__.py", line 395, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/base.py", line 330, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/base.py", line 371, in execute
output = self.handle(*args, **options)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/commands/flush.py", line 80, in handle
emit_post_migrate_signal(verbosity, interactive, database)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/sql.py", line 48, in emit_post_migrate_signal
models.signals.post_migrate.send(
File "/home/luc/.local/lib/python3.9/site-packages/django/dispatch/dispatcher.py", line 177, in send
return [
File "/home/luc/.local/lib/python3.9/site-packages/django/dispatch/dispatcher.py", line 178, in <listcomp>
(receiver, receiver(signal=self, sender=sender, **named))
File "/home/luc/.local/lib/python3.9/site-packages/django/contrib/auth/management/__init__.py", line 42, in create_permissions
create_contenttypes(app_config, verbosity=verbosity, interactive=interactive, using=using, apps=apps, **kwargs)
File "/home/luc/.local/lib/python3.9/site-packages/django/contrib/contenttypes/management/__init__.py", line 132, in create_contenttypes
ContentType.objects.using(using).bulk_create(cts)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/models/query.py", line 506, in bulk_create
returned_columns = self._batched_insert(
File "/home/luc/.local/lib/python3.9/site-packages/django/db/models/query.py", line 1277, in _batched_insert
self._insert(item, fields=fields, using=self.db, ignore_conflicts=ignore_conflicts)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/models/query.py", line 1254, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/models/sql/compiler.py", line 1397, in execute_sql
cursor.execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 98, in execute
return super().execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 66, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 413, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.IntegrityError: NOT NULL constraint failed: django_content_type.name
While trying to migrate, the following error occured:
Operations to perform:
Apply all migrations: admin, api, auth, contenttypes, sessions
Running migrations:
Applying api.0001_initial...Traceback (most recent call last):
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 82, in _execute
return self.cursor.execute(sql)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 411, in execute
return Database.Cursor.execute(self, query)
sqlite3.OperationalError: duplicate column name: ID
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/luc/projects/PySorge/API/manage.py", line 22, in <module>
main()
File "/home/luc/projects/PySorge/API/manage.py", line 18, in main
execute_from_command_line(sys.argv)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
utility.execute()
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/__init__.py", line 395, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/base.py", line 330, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/base.py", line 371, in execute
output = self.handle(*args, **options)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/base.py", line 85, in wrapped
res = handle_func(*args, **kwargs)
File "/home/luc/.local/lib/python3.9/site-packages/django/core/management/commands/migrate.py", line 243, in handle
post_migrate_state = executor.migrate(
File "/home/luc/.local/lib/python3.9/site-packages/django/db/migrations/executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/migrations/executor.py", line 227, in apply_migration
state = migration.apply(state, schema_editor)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/migrations/migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/migrations/operations/models.py", line 92, in database_forwards
schema_editor.create_model(model)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/base/schema.py", line 324, in create_model
self.execute(sql, params or None)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/base/schema.py", line 142, in execute
cursor.execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 98, in execute
return super().execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 66, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/utils.py", line 82, in _execute
return self.cursor.execute(sql)
File "/home/luc/.local/lib/python3.9/site-packages/django/db/backends/sqlite3/base.py", line 411, in execute
return Database.Cursor.execute(self, query)
django.db.utils.OperationalError: duplicate column name: ID
I'm using django version 3.1.6. I'm not really sure how to fix this as I'm not very familiar with databases. Seems like the error is caused by a duplicate field id - my current database setup does have a field named ID.

Answer 1

My recommendation, although certainly not the best way forward, would be to delete the database (delete the actual sqlite3 file in your project) then delete all of your previous migrations, and then try making migrations again.

Answer 2

I had a very old Django site (still had South migrations in tree!) that had been ticking along on a SQLite database forever. At some point Django removed the name column from the django_content_types table. The model uses a property now based on the reflected model class. I've no idea why this hadn't be caught by a Django migration, but I've been known to fake migrations in the blood mist of getting something to run, no-matter-what.
I just dropped the column in ./manage.py dbshell:
ALTER TABLE django_content_type DROP COLUMN name;
And migrations worked again. No ill effects felt. All my old contenttypes are in there, everything still works.

Answer 3

python manage.py reset_db
This will delete all tables. It also helps to delete all migration files in the project if you want a complete wipeout