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 20978 Cannot migrate if on_delete=models.SET_NULL Markus Holtermann loic84 "Given the following models, the `migrate` step fails with `'module' object has no attribute 'set_on_delete'`. {{{ # -*- coding: utf-8 -*- from django.db import models from django.utils.encoding import python_2_unicode_compatible @python_2_unicode_compatible class MyModel(models.Model): name = models.CharField('Name', max_length=50, unique=True) text = models.TextField('Text', blank=True, null=True) class Meta: verbose_name = 'My “fancy” Model' verbose_name_plural = 'My “fancy” Models' def __str__(self): return self.name @python_2_unicode_compatible class OtherModel(models.Model): mymodel = models.ForeignKey(MyModel, null=True, on_delete=models.SET_NULL) value = models.IntegerField('Value', blank=True, null=False, default=50) class Meta: verbose_name = 'Other Model' verbose_name_plural = 'Other Models' def __str__(self): return '%(mymodel)s %(value)d' % { 'mymodel': self.mymodel.name, 'value': self.value, } }}} The migration file looks like {{{ # encoding: utf8 from django.db import models, migrations import django.db.models.deletion class Migration(migrations.Migration): dependencies = [(u'something', '0001_initial')] operations = [ migrations.CreateModel( fields = [(u'id', models.AutoField(verbose_name=u'ID', serialize=False, auto_created=True, primary_key=True),), ('name', models.CharField(unique=True, max_length=50, verbose_name='Name'),), ('text', models.TextField(null=True, verbose_name='Text', blank=True),)], bases = (models.Model,), options = {u'verbose_name': 'My \xe2\x80\x9cfancy\xe2\x80\x9d Model', u'verbose_name_plural': 'My \xe2\x80\x9cfancy\xe2\x80\x9d Models'}, name = 'MyModel', ), migrations.CreateModel( fields = [(u'id', models.AutoField(verbose_name=u'ID', serialize=False, auto_created=True, primary_key=True),), ('mymodel', models.ForeignKey(to=u'something.MyModel', to_field=u'id', null=True, on_delete=django.db.models.deletion.set_on_delete),), ('value', models.IntegerField(default=50, verbose_name='Value', blank=True),)], bases = (models.Model,), options = {u'verbose_name': 'Other Model', u'verbose_name_plural': 'Other Models'}, name = 'OtherModel', ), ] }}} Migrating with Python 3.3: {{{ Traceback (most recent call last): File ""manage.py"", line 10, in execute_from_command_line(sys.argv) File ""/home/markus/.venvs/django-master-py3/src/django/django/core/management/__init__.py"", line 397, in execute_from_command_line utility.execute() File ""/home/markus/.venvs/django-master-py3/src/django/django/core/management/__init__.py"", line 390, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File ""/home/markus/.venvs/django-master-py3/src/django/django/core/management/base.py"", line 242, in run_from_argv self.execute(*args, **options.__dict__) File ""/home/markus/.venvs/django-master-py3/src/django/django/core/management/base.py"", line 289, in execute output = self.handle(*args, **options) File ""/home/markus/.venvs/django-master-py3/src/django/django/core/management/commands/migrate.py"", line 52, in handle executor = MigrationExecutor(connection, self.migration_progress_callback) File ""/home/markus/.venvs/django-master-py3/src/django/django/db/migrations/executor.py"", line 14, in __init__ self.loader.load_disk() File ""/home/markus/.venvs/django-master-py3/src/django/django/db/migrations/loader.py"", line 77, in load_disk migration_module = import_module(""%s.%s"" % (module_name, migration_name)) File ""/home/markus/.venvs/django-master-py3/lib/python3.3/importlib/__init__.py"", line 90, in import_module return _bootstrap._gcd_import(name[level:], package, level) File """", line 1586, in _gcd_import File """", line 1567, in _find_and_load File """", line 1534, in _find_and_load_unlocked File """", line 586, in _check_name_wrapper File """", line 1024, in load_module File """", line 1005, in load_module File """", line 562, in module_for_loader_wrapper File """", line 870, in _load_module File """", line 313, in _call_with_frames_removed File ""/home/markus/Coding/django-testing/example/something/migrations/0001_initial.py"", line 6, in class Migration(migrations.Migration): File ""/home/markus/Coding/django-testing/example/something/migrations/0001_initial.py"", line 20, in Migration fields = [('id', models.AutoField(serialize=False, auto_created=True, primary_key=True, verbose_name='ID'),), ('mymodel', models.ForeignKey(t_field='id', on_delete=django.db.models.deletion.set_on_delete, null=True, to='something.MyModel'),), ('value', models.IntegerField(default=50, bank=True, verbose_name='Value'),)], AttributeError: 'module' object has no attribute 'set_on_delete' }}} Migrating with Python 2.7.5: {{{ Traceback (most recent call last): File ""manage.py"", line 10, in execute_from_command_line(sys.argv) File ""/home/markus/.venvs/django-master-py27/src/django/django/core/management/__init__.py"", line 397, in execute_from_command_line utility.execute() File ""/home/markus/.venvs/django-master-py27/src/django/django/core/management/__init__.py"", line 390, in execute self.fetch_command(subcommand).run_from_argv(self.argv) File ""/home/markus/.venvs/django-master-py27/src/django/django/core/management/base.py"", line 242, in run_from_argv self.execute(*args, **options.__dict__) File ""/home/markus/.venvs/django-master-py27/src/django/django/core/management/base.py"", line 289, in execute output = self.handle(*args, **options) File ""/home/markus/.venvs/django-master-py27/src/django/django/core/management/commands/migrate.py"", line 52, in handle executor = MigrationExecutor(connection, self.migration_progress_callback) File ""/home/markus/.venvs/django-master-py27/src/django/django/db/migrations/executor.py"", line 14, in __init__ self.loader.load_disk() File ""/home/markus/.venvs/django-master-py27/src/django/django/db/migrations/loader.py"", line 77, in load_disk migration_module = import_module(""%s.%s"" % (module_name, migration_name)) File ""/usr/lib64/python2.7/importlib/__init__.py"", line 37, in import_module __import__(name) File ""/home/markus/Coding/django-testing/example/something/migrations/0001_initial.py"", line 6, in class Migration(migrations.Migration): File ""/home/markus/Coding/django-testing/example/something/migrations/0001_initial.py"", line 18, in Migration fields = [(u'id', models.AutoField(verbose_name=u'ID', serialize=False, auto_created=True, primary_key=True),), ('mymodel', models.ForeignKey(to=u'something.MyModel', to_field=u'id', null=True, on_delete=django.db.models.deletion.set_on_delete),), ('value', models.IntegerField(default=50, verbose_name='Value', blank=True),)], AttributeError: 'module' object has no attribute 'set_on_delete' }}}" Bug closed Migrations dev Normal fixed Accepted 1 0 0 0 0 0