id summary reporter owner description type status component version severity resolution keywords cc stage has_patch needs_docs needs_tests needs_better_patch easy ui_ux 34546 "Failed migration yields to unmigratable app: ""OperationalError: (1050, ""Table '' already exists"")""" Natalia Bidart nobody "tl;dr While applying existing (and valid) migrations to a MySQL database, one of them failed with: {{{ ValueError: The database backend does not accept 0 as a value for AutoField. }}} and after fixing the migration by hand, re-running `migrate` yields to this error: {{{ MySQLdb.OperationalError: (1050, ""Table 'testapp_modelz' already exists"") }}} I'm reporting this as a bug because it's unclear to the user how they should proceed in this case. If the ticket is found invalid (likely), then perhaps we could consider adding to the error message an extra note on further steps? My naïve hope, as a user, was that after fixing the migration, a second run of `migrate` would succeed. Longer description: I have Django test project with some test apps in it. I usually switch the database settings to either use sqlite or Postgresql. Recently, I wanted to debug a issue using a MySQL database, so I started one using docker and I ensured I had a valid connection: {{{ $ python -Wall manage.py dbshell Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 14 Server version: 8.0.33 MySQL Community Server - GPL ... mysql> }}} Then, I made sure I had no pending migrations to generate, and immediately after I applied all the migrations: {{{ $ python -Wall manage.py makemigrations No changes detected $ python -Wall manage.py migrate Operations to perform: Apply all migrations: admin, auth, contenttypes, sessions, testapp, ticket_30382 Running migrations: Applying contenttypes.0001_initial... OK Applying auth.0001_initial... OK Applying admin.0001_initial... OK Applying admin.0002_logentry_remove_auto_add... OK Applying admin.0003_logentry_add_action_flag_choices... OK Applying contenttypes.0002_remove_content_type_name... OK Applying auth.0002_alter_permission_name_max_length... OK Applying auth.0003_alter_user_email_max_length... OK Applying auth.0004_alter_user_username_opts... OK Applying auth.0005_alter_user_last_login_null... OK Applying auth.0006_require_contenttypes_0002... OK Applying auth.0007_alter_validators_add_error_messages... OK Applying auth.0008_alter_user_username_max_length... OK Applying auth.0009_alter_user_last_name_max_length... OK Applying auth.0010_alter_group_name_max_length... OK Applying auth.0011_update_proxy_permissions... OK Applying auth.0012_alter_user_first_name_max_length... OK Applying sessions.0001_initial... OK Applying testapp.0001_initial... OK Applying testapp.0002_remove_grandchild_age_alter_child_parent_and_more... OK Applying testapp.0003_alter_article_authors... OK Applying testapp.0004_question_voter_choice... OK Applying testapp.0005_product_remove_choice_voters_images_delete_voter... OK Applying testapp.0006_modela_modelb... OK Applying testapp.0007_modelb_foo... OK Applying testapp.0008_rename_foo_modelb__foo... OK Applying testapp.0009_modelz_remove_modelb_id_modelb_modelz_ptr...Traceback (most recent call last): File ""/home/nessita/fellowship/projectfromrepo/manage.py"", line 22, in main() File ""/home/nessita/fellowship/projectfromrepo/manage.py"", line 18, in main execute_from_command_line(sys.argv) File ""/home/nessita/fellowship/django/django/core/management/__init__.py"", line 442, in execute_from_command_line utility.execute() File ""/home/nessita/fellowship/django/django/core/management/__init__.py"", line 436, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File ""/home/nessita/fellowship/django/django/core/management/base.py"", line 412, in run_from_argv self.execute(*args, **cmd_options) File ""/home/nessita/fellowship/django/django/core/management/base.py"", line 458, in execute output = self.handle(*args, **options) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/core/management/base.py"", line 106, in wrapper res = handle_func(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/core/management/commands/migrate.py"", line 356, in handle post_migrate_state = executor.migrate( ^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/executor.py"", line 135, in migrate state = self._migrate_all_forwards( ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/executor.py"", line 167, in _migrate_all_forwards state = self.apply_migration( ^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/executor.py"", line 252, in apply_migration state = migration.apply(state, schema_editor) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/migration.py"", line 132, in apply operation.database_forwards( File ""/home/nessita/fellowship/django/django/db/migrations/operations/fields.py"", line 108, in database_forwards schema_editor.add_field( File ""/home/nessita/fellowship/django/django/db/backends/mysql/schema.py"", line 107, in add_field super().add_field(model, field) File ""/home/nessita/fellowship/django/django/db/backends/base/schema.py"", line 668, in add_field definition, params = self.column_sql(model, field, include_default=True) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/base/schema.py"", line 359, in column_sql "" "".join( File ""/home/nessita/fellowship/django/django/db/backends/base/schema.py"", line 310, in _iter_column_sql default_value = self.effective_default(field) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/base/schema.py"", line 429, in effective_default return field.get_db_prep_save(self._effective_default(field), self.connection) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/models/fields/related.py"", line 1149, in get_db_prep_save return self.target_field.get_db_prep_save(value, connection=connection) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/models/fields/__init__.py"", line 957, in get_db_prep_save return self.get_db_prep_value(value, connection=connection, prepared=False) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/models/fields/__init__.py"", line 2748, in get_db_prep_value value = connection.ops.validate_autopk_value(value) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/mysql/operations.py"", line 250, in validate_autopk_value raise ValueError( ValueError: The database backend does not accept 0 as a value for AutoField. }}} I edited the troubling migration by hand, changing the default from `0` to `1`, but `migrate` would no longer work: {{{ $ python -Wall manage.py migrate Operations to perform: Apply all migrations: admin, auth, contenttypes, sessions, testapp, ticket_30382 Running migrations: Applying testapp.0009_modelz_remove_modelb_id_modelb_modelz_ptr...Traceback (most recent call last): File ""/home/nessita/fellowship/django/django/db/backends/utils.py"", line 87, in _execute return self.cursor.execute(sql) ^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/mysql/base.py"", line 75, in execute return self.cursor.execute(query, args) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/.virtualenvs/djangodev/lib/python3.11/site-packages/MySQLdb/cursors.py"", line 206, in execute res = self._query(query) ^^^^^^^^^^^^^^^^^^ File ""/home/nessita/.virtualenvs/djangodev/lib/python3.11/site-packages/MySQLdb/cursors.py"", line 319, in _query db.query(q) File ""/home/nessita/.virtualenvs/djangodev/lib/python3.11/site-packages/MySQLdb/connections.py"", line 254, in query _mysql.connection.query(self, query) MySQLdb.OperationalError: (1050, ""Table 'testapp_modelz' already exists"") The above exception was the direct cause of the following exception: Traceback (most recent call last): File ""/home/nessita/fellowship/projectfromrepo/manage.py"", line 22, in main() File ""/home/nessita/fellowship/projectfromrepo/manage.py"", line 18, in main execute_from_command_line(sys.argv) File ""/home/nessita/fellowship/django/django/core/management/__init__.py"", line 442, in execute_from_command_line utility.execute() File ""/home/nessita/fellowship/django/django/core/management/__init__.py"", line 436, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File ""/home/nessita/fellowship/django/django/core/management/base.py"", line 412, in run_from_argv self.execute(*args, **cmd_options) File ""/home/nessita/fellowship/django/django/core/management/base.py"", line 458, in execute output = self.handle(*args, **options) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/core/management/base.py"", line 106, in wrapper res = handle_func(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/core/management/commands/migrate.py"", line 356, in handle post_migrate_state = executor.migrate( ^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/executor.py"", line 135, in migrate state = self._migrate_all_forwards( ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/executor.py"", line 167, in _migrate_all_forwards state = self.apply_migration( ^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/executor.py"", line 252, in apply_migration state = migration.apply(state, schema_editor) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/migrations/migration.py"", line 132, in apply operation.database_forwards( File ""/home/nessita/fellowship/django/django/db/migrations/operations/models.py"", line 96, in database_forwards schema_editor.create_model(model) File ""/home/nessita/fellowship/django/django/db/backends/base/schema.py"", line 451, in create_model self.execute(sql, params or None) File ""/home/nessita/fellowship/django/django/db/backends/base/schema.py"", line 201, in execute cursor.execute(sql, params) File ""/home/nessita/fellowship/django/django/db/backends/utils.py"", line 102, in execute return super().execute(sql, params) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/utils.py"", line 67, in execute return self._execute_with_wrappers( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/utils.py"", line 80, in _execute_with_wrappers return executor(sql, params, many, context) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/utils.py"", line 84, in _execute with self.db.wrap_database_errors: File ""/home/nessita/fellowship/django/django/db/utils.py"", line 91, in __exit__ raise dj_exc_value.with_traceback(traceback) from exc_value File ""/home/nessita/fellowship/django/django/db/backends/utils.py"", line 87, in _execute return self.cursor.execute(sql) ^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/fellowship/django/django/db/backends/mysql/base.py"", line 75, in execute return self.cursor.execute(query, args) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File ""/home/nessita/.virtualenvs/djangodev/lib/python3.11/site-packages/MySQLdb/cursors.py"", line 206, in execute res = self._query(query) ^^^^^^^^^^^^^^^^^^ File ""/home/nessita/.virtualenvs/djangodev/lib/python3.11/site-packages/MySQLdb/cursors.py"", line 319, in _query db.query(q) File ""/home/nessita/.virtualenvs/djangodev/lib/python3.11/site-packages/MySQLdb/connections.py"", line 254, in query _mysql.connection.query(self, query) django.db.utils.OperationalError: (1050, ""Table 'testapp_modelz' already exists"") }}} " Bug closed Migrations 4.2 Normal invalid Unreviewed 0 0 0 0 0 0