Django update on queryset to change ID of ForeignKey

Question

I am trying to update the ids of a bunch of objects and a related table that refers to the objects.

class Test(models.Model):
    id=models.IntegerField(primary_key=True)

class Question(models.Model):
    id=models.AutoField(primary_key=True)
    test=models.ForeignKey('Test',db_column='testId')


d={1:2,5:10}

for fr,to in d.items():
    Test.objects.filter(id=fr).update(id=to)
    Question.objects.filter(test_id=fr).update(test_id=to)

I have tried test_id, test__id and testId but get this error message:

django.db.models.fields.FieldDoesNotExist: Question has no field named 'test_id'

Is this currently possible?

Edit: I would prefer not to have to load the Test object for each id change.

Answer 1

Implemented in Django 1.8

Usage:

Bar.objects.filter(pk=foo.id).update(a_id=bar.id)
Bar.objects.filter(pk=foo.id).update(a=bar.id)

See ticket and commit.

Answer 2

You cannot update ForeignKey field with ID. You should pass the model object to update it. You can try

for fr,to in d.items():
    Test.objects.filter(id=fr).update(id=to)
    test_obj = Test.objects.get(id=to)
    Question.objects.filter(test_id=fr).update(test=test_obj)

Refer Documentation

Update:

From Django 1.8, you can use id of ForeignKey object to update an object.

for fr,to in d.items():
    Test.objects.filter(id=fr).update(id=to)
    Question.objects.filter(test_id=fr).update(test_id=to)