django south migration, doesnt set default

Question

I use south to migrate my django models. There is however a nasty bug in south. It doesn\'t set default values in Postgres Databases. Example:

created_at = model         


        

Answer 1

As mentioned in earlier answers, the default mechanism in django is implemented in the model class, and is not relevant to south migrations.

Also, since south 0.8, the keep_default flag is deprecated, and won't add the default value to your model.

What I do to solve this is writing a custom migration to add the default value. You can do that by creating a separate data migration:

./manage.py datamigration your_app_name migration_name

and add the following line to the forwards function:

orm.YourModel.objects.update(field_name = DEFAULT_VALUE)

Alternatively, instead of creating a new migration, you can modify your original migration:

1. add no_dry_run = True to the class itself (so you will have access to the ORM).
2. add orm.YourModel.objects.update(field_name = DEFAULT_VALUE) to the end of the forwards function.

This way you don't have to write a backwards migration, because you already have the original delete-column one.