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.

Answer 1

I faced this problem. for solving problem follow the step.
1.open Database and table.
2.Create a required(sites_site.airport_codes in question ) column which was not exits in your table with default value.

3.run the command

python manage.py makemigrations

python manage.py migrate <app name>

python manage.py runserver

Answer 2

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 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.

Answer 4

I ran into this problem recently after upgrading to Django 1.11. I wanted to permanently address the issue so I wouldn't have to comment / uncomment code every time I ran a migration on the table, so my approach:

from django.db.utils import ProgrammingError as AvoidDataMigrationError

try:
    ... do stuff that breaks migrations
except AvoidDataMigrationError:
    pass

I rename the exception during import to AvoidDataMigrationError so it's clear why it's there.

Answer 5

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 6

I too got same issue when i executed a cmd like python manage.py makemigrations app1. I resolved my issue by commenting the custom orms which is running in another app2 under views.

Example:

inside app1 models.py

class ModelA(models.Model):
    subject = models.CharField(max_length=1)
    course = models.CharField(max_length=1)

inside app2 view.py

# obj = ModelA.object.all()
# get_subjct = [s.subject for s in obj]

So here i have commented above code and executed the makemigrations and migrate then uncommented.

Working fine...