I already have model topic and have data in it, when I tried to use MPTTMODEL insted of the regular model
class Topic(MPTTModel):
parent = TreeForeignKey('self', null=True, blank=True, related_name='children')
....
so I run the following command to migrate the parent column in the topic table
./manage.py evolve --hint --execute
but I get this error
Error: Cannot use hinted evolution: AddField or ChangeField mutation for 'Topic.rght' in 'core' requires user-specified initial value.
it works fine with new model, but with existing Model that has data it raise this error