South migration fails

Question

I have a problem with south migrations. I still don't understand how this did happen, and what should what path to move to resolve this

Romans-MacBook-Pro:holms$ ./manage.py migrate 
cRunning migrations for accounts:
- Nothing to migrate.
 - Loading initial data for accounts.
No fixtures found.
Running migrations for allocations:
- Nothing to migrate.
 - Loading initial data for allocations.
No fixtures found.
Running migrations for adyen:
- Nothing to migrate.
 - Loading initial data for adyen.
No fixtures found.
Running migrations for blog:
- Nothing to migrate.
 - Loading initial data for blog.
No fixtures found.
Running migrations for offers:
- Nothing to migrate.
 - Loading initial data for offers.
No fixtures found.
Running migrations for orders:
 - Migrating forwards to 0011_update_price_fields.
 > orders:0002_update_order_contact_information
Traceback (most recent call last):
  File "./manage.py", line 15, in <module>
    execute_manager(settings)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 438, in execute_manager
    utility.execute()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/__init__.py", line 379, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/base.py", line 191, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/management/base.py", line 220, in execute
    output = self.handle(*args, **options)
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/management/commands/migrate.py", line 105, in handle
    ignore_ghosts = ignore_ghosts,
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/__init__.py", line 191, in migrate_app
    success = migrator.migrate_many(target, workplan, database)
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/migrators.py", line 221, in migrate_many
    result = migrator.__class__.migrate_many(migrator, target, migrations, database)
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/migrators.py", line 292, in migrate_many
    result = self.migrate(migration, database)
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/migrators.py", line 125, in migrate
    result = self.run(migration)
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/migrators.py", line 99, in run
    return self.run_migration(migration)
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/migrators.py", line 81, in run_migration
    migration_function()
  File "/Users/holms/Development/xxx/xxx/settings/../../lib/south/migration/migrators.py", line 57, in <lambda>
    return (lambda: direction(orm))
  File "/Users/holms/Development/xxx/migrations/0002_update_order_contact_information.py", line 29, in forwards
    for o in orders:
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 107, in _result_iter
    self._fill_cache()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 772, in _fill_cache
    self._result_cache.append(self._iter.next())
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/query.py", line 273, in iterator
    for row in compiler.results_iter():
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 680, in results_iter
    for rows in self.execute_sql(MULTI):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 735, in execute_sql
    cursor.execute(sql, params)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/util.py", line 34, in execute
    return self.cursor.execute(sql, params)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py", line 234, in execute
    return Database.Cursor.execute(self, query, params)
django.db.utils.DatabaseError: no such column: orders_order.pre_paid

part of migration file [0002_update_order_contact_information.py] which breaks:

# encoding: utf-8
import datetime
from south.db import db
from south.v2 import DataMigration
from django.db import models

class Migration(DataMigration):

    def forwards(self, orm):
        Order = models.get_model('orders', 'Order')

        orders = Order.all_objects.select_related('buyer')
        orders = orders.filter(first_name__isnull=True)
        orders = orders.filter(buyer__isnull=False)
        orders = orders.exclude(payment_status="UNFINISHED")

        userfields = (
            'gender', 'birth_date', 'first_name', 'last_name', 'street_number',

Answer 1

You should not interact with your models directly like that. You use django.models, but that version of the models are in a wrong state. You want the state of the models as they were in migration 0002. The south manual states that you should access your models through the orm parameter.

Notice that we use orm.User to access the User model - this gives us the version of User from when this migration was created, so if we want to run the migration in future, it won’t get a completely different, new, User model. source

So you should rewrite the migration like this:

orders = orm.Order.objects.all()

Or even like this:

Order = orm.Order