(ll_env) C:jiaguolearning_logs>python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, learning_log, sessions
Running migrations:
  Applying learning_log.0003_entry_topic...Traceback (most recent call last):
  File "manage.py", line 15, in <module>
    execute_from_command_line(sys.argv)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangocoremanagement__init__.py", line 371, in execute_from_command_line
    utility.execute()
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangocoremanagement__init__.py", line 365, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangocoremanagementbase.py", line 288, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangocoremanagementbase.py", line 335, in execute
    output = self.handle(*args, **options)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangocoremanagementcommandsmigrate.py", line 200, in handle
    fake_initial=fake_initial,
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmigrationsexecutor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmigrationsexecutor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmigrationsexecutor.py", line 244, in apply_migration
    state = migration.apply(state, schema_editor)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmigrationsmigration.py", line 122, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmigrationsoperationsfields.py", line 84, in database_forwards
    field,
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbbackendssqlite3schema.py", line 306, in add_field
    self._remake_table(model, create_field=field)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbbackendssqlite3schema.py", line 178, in _remake_table
    self.effective_default(create_field)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbbackendsbaseschema.py", line 240, in effective_default
    default = field.get_db_prep_save(default, self.connection)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmodelsfieldsrelated.py", line 936, in get_db_prep_save
    return self.target_field.get_db_prep_save(value, connection=connection)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmodelsfields__init__.py", line 767, in get_db_prep_save
    return self.get_db_prep_value(value, connection=connection, prepared=False)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmodelsfields__init__.py", line 939, in get_db_prep_value
    value = self.get_prep_value(value)
  File "C:jiaguolearning_logsll_envlibsite-packagesdjangodbmodelsfields__init__.py", line 947, in get_prep_value
    return int(value)
TypeError: int() argument must be a string, a bytes-like object or a number, not 'datetime.datetime'