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 33280 [bug] migration don't work with multiple databases (sometimes) razielvamp666 nobody "My configuration is: {{{ python 3.7.1 }}} {{{ Django==2.2.24 django-axes==5.16.0 django-bootstrap-modal-forms==1.3.1 django-celery-results==1.0.4 django-cors-headers==3.1.1 django-database-view==0.3.0 django-debug-toolbar==1.11 django-dynamic-db-router==0.3.0 django-ipware==3.0.7 django-redis-cache==3.0.0 django-redis-sessions==0.6.2 django-ses==1.0.3 django-storages==1.12.3 django-taggit==0.24.0 djangorestframework==3.12.4 pytest-django==4.4.0 }}} I using Django with multiple databases and default DB is not set for security reasons (I prefer to get error if Django will fallback to `default` connection, because it means that current tenant DB is not used for some reasons). so `default` connection is empty (`{}`). When I run `python manage.py migrate --database=some_db_name` I've get error: {{{ Applying app_name.0154_migration_name...Traceback (most recent call last): File ""manage.py"", line 41, in execute_from_command_line(sys.argv) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/core/management/__init__.py"", line 381, in execute_from_command_line utility.execute() File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/core/management/__init__.py"", line 375, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/core/management/base.py"", line 323, in run_from_argv self.execute(*args, **cmd_options) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/core/management/base.py"", line 364, in execute output = self.handle(*args, **options) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/core/management/base.py"", line 83, in wrapped res = handle_func(*args, **kwargs) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/core/management/commands/migrate.py"", line 234, in handle fake_initial=fake_initial, File ""/user/.pyenv/versions/gl/lib/python3.7/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 ""/user/.pyenv/versions/gl/lib/python3.7/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 ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/migrations/executor.py"", line 245, in apply_migration state = migration.apply(state, schema_editor) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/migrations/migration.py"", line 124, in apply operation.database_forwards(self.app_label, schema_editor, old_state, project_state) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/dbview/helpers.py"", line 21, in database_forwards self._create_standard_view(model, schema_editor) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/dbview/helpers.py"", line 60, in _create_standard_view qs = str(model.view()) File ""/user/code/genki_labo/orm_django/models/novel_coronavirus_vaccine.py"", line 136, in view return str(qs.query) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/query.py"", line 265, in __str__ sql, params = self.sql_with_params() File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/query.py"", line 273, in sql_with_params return self.get_compiler(DEFAULT_DB_ALIAS).as_sql() File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/compiler.py"", line 474, in as_sql extra_select, order_by, group_by = self.pre_sql_setup() File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/compiler.py"", line 54, in pre_sql_setup self.setup_query() File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/compiler.py"", line 45, in setup_query self.select, self.klass_info, self.annotation_col_map = self.get_select() File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/compiler.py"", line 254, in get_select sql, params = self.compile(col, select_format=True) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/compiler.py"", line 405, in compile sql, params = node.as_sql(self, self.connection) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/expressions.py"", line 737, in as_sql return ""%s.%s"" % (qn(self.alias), qn(self.target.column)), [] File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/models/sql/compiler.py"", line 396, in quote_name_unless_alias r = self.connection.ops.quote_name(name) File ""/user/.pyenv/versions/gl/lib/python3.7/site-packages/django/db/backends/dummy/base.py"", line 20, in complain raise ImproperlyConfigured(""settings.DATABASES is improperly configured. "" django.core.exceptions.ImproperlyConfigured: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details. }}} You can see that problem is here: {{{ return self.get_compiler(DEFAULT_DB_ALIAS).as_sql() }}} `DEFAULT_DB_ALIAS` is `default` and it hardcoded. Also `DEFAULT_DB_ALIAS` is used couple of times inside `django/db/models/sql/query.py` (please search by `DEFAULT_DB_ALIAS` in file to see details) It should use CURRENT_DB as other parts of Django Unfortunately I didn't check how migration determines current DB when `--database=...` is set so can't recommend exact solution, but I may see couple hints: 1. DB may be get from `--database=...` directly (But not sure if that is a correct solution). 2. DB may be get from [`DatabaseRouter`](https://docs.djangoproject.com/en/2.2/topics/db/multi-db/#database-routers) as other parts of Django (It is looking like correct solution) 3. Here should be `using` option to be able set connection DB directly (for example, all functions inside `django/db/transaction.py` has `using` argument to be able set connection name directly) Right now I using workaround and set `from django.conf import settings; settings.DATABASES['default'] = current_db_taken_from_cmd` if command is `migrate`. Not all migrations fail. I don't know reason why it happens only with specific migrations, but I guess that it because this migration doing `CreateView` Migration file is looking like: {{{ # Generated by Django 2.2.10 on 2021-10-06 04:17 from dbview.helpers import CreateView import common.enums.some_enum from django.db import migrations, models import django.db.models.deletion class Migration(migrations.Migration): dependencies = [ ('app_name', '0153_previous_migration'), ] operations = [ migrations.CreateModel( name='SomeName', fields=[ ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')), ('create_datetime', models.DateTimeField(auto_now_add=True, verbose_name='A')), ('user', models.CharField(default='admin', max_length=32, verbose_name='B')), ('update_datetime', models.DateTimeField(auto_now=True, verbose_name='C')), ... ], options={ 'db_table': 'table_name', 'unique_together': {('other_table', 'table_name')}, }, ), CreateView( name='SomeNameView', fields=[ ('table_name_1', models.OneToOneField(on_delete=django.db.models.deletion.PROTECT, primary_key=True, serialize=False, to='orm_django.ApplyingInformation')), ('table_name_2', models.IntegerField(verbose_name='A')), ('table_name_3', models.IntegerField(verbose_name='B')), ('table_name_3', models.IntegerField(verbose_name='C')), ... ], options={ 'db_table': 'table_view', }, ), migrations.AddIndex( model_name='modelname', index=models.Index(fields=['field_A', 'field_B', ...], name='index_name'), ), ] }}}" Bug new Database layer (models, ORM) 2.2 Normal orm migration Unreviewed 0 0 0 0 0 0