Ben Ben - 4 months ago 28
Python Question

Foreign key from one app into another in Django

I'm wondering if it's possible to define a foreign key in a models.py file in Django that is a reference to a table in another app?

In other words, I have two apps, called cf and profiles, and in cf/models.py I have (amongst other things):

class Movie(models.Model):
title = models.CharField(max_length=255)


and in profiles/models.py I want to have:

class MovieProperty(models.Model):
movie = models.ForeignKey(Movie)


But I can't get it to work. I've tried:

movie = models.ForeignKey(cf.Movie)


and I've tried importing cf.Movie at the beginning of models.py, but I always get errors, such as:

NameError: name 'User' is not defined


Am I breaking the rules by trying to tie two apps together in this way, or have I just got the syntax wrong?

Answer

According to the docs, your second attempt should work:

To refer to models defined in another application, you must instead explicitly specify the application label. For example, if the Manufacturer model above is defined in another application called production, you'd need to use:

class Car(models.Model):
    manufacturer = models.ForeignKey('production.Manufacturer')

Have you tried putting it into quotes?