我正在使用Django 1.9编写代码库，我正忙着准备一切升级到1.10。

从python社交身份验证迁移到python社交身份验证应用django后，我遇到了一个问题。我已使用此处找到的步骤

更新设置和网址文件后，我遇到了以下错误。有人知道我该如何解决吗？

Running migrations:
  Rendering model states... DONE
  Applying social_django.0006_partial... OK
  Applying social_django.0007_code_timestamp... OK
  Applying social_django.0008_partial_timestamp... OK
  Applying social_django.0009_auto_20191118_0520...Traceback (most recent call last):
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
psycopg2.IntegrityError: column "modified" contains null values


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 "/home/brendan/venvs/social/lib/python3.6/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
    utility.execute()
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/core/management/__init__.py", line 345, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/core/management/base.py", line 348, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/core/management/base.py", line 399, in execute
    output = self.handle(*args, **options)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 200, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/migrations/executor.py", line 92, in migrate
    self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/migrations/executor.py", line 121, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/migrations/executor.py", line 198, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/migrations/migration.py", line 123, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/migrations/operations/fields.py", line 62, in database_forwards
    field,
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 396, in add_field
    self.execute(sql, params)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 110, in execute
    cursor.execute(sql, params)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/backends/utils.py", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/utils.py", line 95, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/utils/six.py", line 685, in reraise
    raise value.with_traceback(tb)
  File "/home/brendan/venvs/social/lib/python3.6/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
django.db.utils.IntegrityError: column "modified" contains null values