Django Migration Error: Column does not exist

Question

Python 3, Django 1.8.5, Postgres

I have a model Sites that has been working fine. I recently tried to add a field, airport_code, and migrate the data.

class Site(BaseModel):

  objects = SiteManager()

  name = models.CharField(max_length=200, unique=True)
  domain = models.CharField(max_length=200, unique=True)
  weather = models.CharField(max_length=10)
  nearby_sites = models.ManyToManyField('self', symmetrical=False, blank=True)
  users = models.ManyToManyField(settings.AUTH_USER_MODEL, blank=True)
  facebook = models.URLField(max_length=200)
  twitter = models.URLField(max_length=200)
  header_override = models.TextField(blank=True)
  email_header_override = models.TextField(blank=True)
  timely_site_tag_id = models.IntegerField()
  timely_featured_tag_id = models.IntegerField()
  timely_domain = models.CharField(max_length=255)
  sitemap_public_id = models.CharField(max_length=255)
  state = models.CharField(max_length=24)
  airport_code = JSONField()

However, when I ran makemigrations I got an error:

django.db.utils.ProgrammingError: column sites_site.airport_code does not exist LINE 1: ..._site"."sitemap_public_id", "sites_site"."state", "sites_sit...

Of course, this doesn't make sense, because the column obviously does not exist when I'm trying to create it within the migration.

I have seen many questions about this bug on Stack Overflow that are unanswered, or have a solution to manually create the migration file, or destroy and rebuild the database. This is not an okay solution.

Answer 1

After you run makemigrations, be sure to go through the stack trace step by step.

In my case, I noticed it traced through a call to a Form contained within a forms.py in a completely different app, which happened to have a call to the model I was trying to create a new migration for.

Moving the Form class out of forms.py into the views.py fixed the issue.

Answer 2

This bug was resolved for me by commenting out the django debug toolbar from INSTALLED_APPS in settings.py. I am not sure why debug toolbar is the culprit, but after I commented it out, I was able to run makemigrations and migrate with no issue.

Hoping this helps someone, as I spent twelve hours trying to figure it out.

Answer 3

I ran into this issue as well and the answer by @Nexus helped. I thought I'd provide details of my specific case here for better illustrate the cause of the issue. It seems like a potential bug to me.

I have a model Brand as follows:

class Brand(BaseModelClass):
    name = CharField(max_length=256, unique=True)
    website = ForeignKey(URL, on_delete=CASCADE, null=True, blank=True)

I was running a python manage.py makemigrations after adding a Boolean field as follows:

class Brand(BaseModelClass):
    name = CharField(max_length=256, unique=True)
    website = ForeignKey(URL, on_delete=CASCADE, null=True, blank=True)
    trusted = Boolean(default=True)

When running the makemigrations command, I recieved an error similar to OP's:

django.db.utils.ProgrammingError: column appname_brand.trusted does not exist

Per @Nexus' suggestion, I went through the stacktrace, line-by-line, assuming that it wasn't some core issue with Django. As it turns out, in one of apps forms.py file I had the following:

choices={(str(brand.id), brand.name) for brand in Brand.objects.all()}

The solution was to simply comment-out that line, run manage.py makemigrations, then run manage.py migrate. Afterwards, I uncommented the line and everything and my forms' functionality worked just as before.