Question

I am getting an DatabaseError saying no column named playlist exists and I’m trying to figure out how to fix it. I’m using South. I deleted the old files in the my migrations folder and ran:

python manage.py schemamigration app_name --initial
python manage.py migrate reserve

I get this error when I do that:

south.exceptions.GhostMigrations: 

 ! These migrations are in the database but not on disk:
    <reserve: 0002_initial>
 ! I'm not trusting myself; either fix this yourself by fiddling
 ! with the south_migrationhistory table, or pass --delete-ghost-migrations
 ! to South to have it delete ALL of these records (this may not be good). 

I’m not sure how to get rid of this error, since in my migrations folder I only have init.py(c) and 0001_initial.py(c); I don’t have 0002 migration file anymore.

When I try runserver and click “add playlist” in the admin, this is when I get the DatabaseError. If it helps, my models.py is:

class UserProfile(models.Model):
    user = models.OneToOneField(User)
    def __unicode__(self):
        return self.user

def create_user_profile(sender, instance, created, **kwargs):
    if created:
        UserProfile.objects.create(user=instance)

post_save.connect(create_user_profile, sender=User)         

class Playlist(models.Model):
    playlist = models.CharField('Playlist', max_length = 2000, null=True, blank=True)
    def __unicode__(self):
        return self.playlist

class Video(models.Model):
    video_url = models.URLField('Link to video', max_length = 200, null=True, blank=True)
    def __unicode__(self):
        return self.video_url

class UserPlaylist(models.Model):
    profile = models.ForeignKey(User)
    playlist = models.ForeignKey(Playlist)
    def __unicode__(self):
        return self.playlist

class Videoplaylist(models.Model):
    video = models.ForeignKey(Video)
    playlist = models.ForeignKey(UserPlaylist)
    def __unicode__(self):
        return self.playlist

Any advice on how to fix this?

Answer 1

South stores migration information in the database too, in a table called “migrations”. [ I think thats the table name; writing this from memory ].

You need to clear that table out.

Note

• Once you clear that table out, you have to start the migrations again from scratch; right from the initial migration.
• It would be a good idea to make a copy of your database as-is before you do this. I assume that your code is already version controlled.