Add data with Django data migration

Question

Is it possible to add, data do DB with South data migration in Django? I don't mean change of DB structure, I need to change the value of some fields. I know that it could be done via Django admin, but I need migration way.

Answer 1

Absolutely. You need to use data migrations. With south, you can call

$ ./manage.py datamigration <app_name> <migration_name>

which will create a data migration file in your migrations module. You can then do your migration in forwards(self, orm) function. Just make sure that when accessing models, you use orm. For example, if I wanted to prefix every User's username

def forwards(self, orm):
    for user in orm.User.objects.all():
        user.username = 'prefix' + user.username
        user.save()

You can find more information in the official tutorial.