Question

How do I travel through multiple foreign keys in Django? I’ve tried everything I can think of from the django docs, but I’m obviously missed something (extreme newbie). I have models for scientists, experiments, and theories.

If I want to look at a particular Theory (let’s call it ‘relativity’) and get a list of all of the emails of scientists working on it (kept in the normal django user model), how do I do this?

---

class Experiment(models.Model)

    experimenter = models.ForeignKey(Scientist)
    theory = models.ForeignKey(Theory)


class Theory(models.Model)

    name = models.CharField(max_length=100)

class Scientist(models.Model)

    user = models.ForeignKey(User, unique=True)
    institution = models.CharField(max_length=20, null=True, blank=True)

---

These are simplified versions of my models that I rewrote, so there are probably some errors in it, but the relationships are correct.

I’ve tried every kind of combinations of select_related(), get(), filter() but can’t figure it out. Thanks in advance for your help!

Answer 1

User.objects.filter(scientist__experiment__theory__name=u'relativity')