[Answered ]-How to create a migration after adding an hstore field? (django-hstore vs. South)

this message usually appears when South is trying to update your models on the database and finds existing rows on the table yo are trying to modify. In order to continue and create the new field on database you must specify a value for the existing rows of tha table you are migrating. What I usually do, if it is a development stage, I go for option number 2 and set the value to 0, {} empty dict, or even NULL, depending on the field type.

As already mentionned, when you hit 2, you can either go for an empty string (“”) or fill the field the way it’s stored:

? The field 'MyModel.data' does not have a default specified, yet is NOT NULL.
? Since you are adding this field, you MUST specify a default
? value to use for existing rows. Would you like to:
?  1. Quit now, and add a default to the field in models.py
?  2. Specify a one-off value to use for existing columns now
? Please select a choice: 2
? Please enter Python code for your one-off default value.
? The datetime module is available, so you can do e.g. datetime.date.today()
>>> "foo=>bar,foo2=>bar2"