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

Make sure you are not doing any queries when loading the application!, as eg. in:

class A:
  field = fn_that_makes_query()

When running migrate or makemigrations, Django performs system checks, which loads the entire application, so if during this process any queries are made which use added/altered db fields you run into inconsitencies, because you are trying to access db fileds that are not there yet.