How to remove a field in Django model - variation on answered question - python-3.x

Question

Although a couple of similar question were posted, none of those questions are the same as my case.
I had a model that looked like this:
class Person(models.Model):
"""Definition of persons that will fulfill a role in a committee
or will be in a way associated with a committee as an administrator
"""
ClientId = models.ForeignKey('clients.Client', on_delete=models.CASCADE,
to_field='id')
PersNumber = models.PositiveIntegerField(null=False)
PersSurName = models.CharField(max_length=40, null=False)
PersNames = models.CharField(max_length=40, null=False)
I set the uniqueness of the record on ClientId and PersNumber.
I have created 3 records in the database.
Along the way I became convinced that I might as well use the auto generated id of the record as the person number (I am learning Django).
I removed the PersNumber from my model and ran makemigrations.
All is well until I ran migrate...
I get the following error:
django.core.exceptions.FieldDoesNotExist: Person has no field named 'PersNumber'
Any idee on how to get past this error
The full trace looks like this:
Operations to perform:
Apply all migrations: admin, auth, clients, contenttypes, komadm_conf, sessions
Running migrations:
Applying komadm_conf.0017_auto_20180830_1806...Traceback (most recent call last):
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\models\options.py", line 564, in get_field
return self.fields_map[field_name]
KeyError: 'PersNumber'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 15, in
execute_from_command_line(sys.argv)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\core\management__init__.py", line 381, in execute_from_command_line
utility.execute()
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\core\management__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\core\management\base.py", line 316, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\core\management\base.py", line 353, in execute
output = self.handle(*args, **options)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\core\management\base.py", line 83, in wrapped
res = handle_func(*args, **kwargs)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\core\management\commands\migrate.py", line 203, in handle
fake_initial=fake_initial,
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\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 "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\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 "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\migrations\executor.py", line 244, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\migrations\migration.py", line 124, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\migrations\operations\fields.py", line 150, in database_forwards
schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\backends\sqlite3\schema.py", line 318, in remove_field
self._remake_table(model, delete_field=field)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\backends\sqlite3\schema.py", line 257, in _remake_table
self.create_model(temp_model)
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\backends\base\schema.py", line 300, in create_model
columns = [model._meta.get_field(field).column for field in fields]
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\backends\base\schema.py", line 300, in
columns = [model._meta.get_field(field).column for field in fields]
File "C:\ApplicationDef\za\co\drie_p\Komadmin.db\KomAdmin\KomadmTest\komadm_app\komadm_env\lib\site-packages\django\db\models\options.py", line 566, in get_field
raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
django.core.exceptions.FieldDoesNotExist: Person has no field named 'PersNumber'

Answer 1

Giving the fact that nobody else answered i will(but i am learning too)..
did you check if this field still exist ? (in the shell for instance).
i'll recommand to manually delete the migration file associated and try again (makemigrations + migrate).
The migration file i am talking about can be found MyProject/Myapp/migrations/00xx_something.py
If it still does not work you can delete the table directly in your database, and the migration file associated.