id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30281	Model.refresh_from_db() does not refresh related objects	Aleksander Zamojski	nobody	"After testing my application with Django 2.0.13 I noticed few of my test started failing (they were working on Django 2.1). After further investigation, I figured out the problem was coming from **refresh_from_db** method.

Here is a test that show the problem:

{{{
def test_error_on_refresh_from_db(self):
    def add_one(id):
        task_model = FakeTask.objects.get(id=id)
        task_model.task_group.finished_tasks_number = F('finished_tasks_number') + 1
        task_model.task_group.save()
        task_model.task_group.refresh_from_db()
        task_model.save()
        self.assertEqual(task_model.task_group.finished_tasks_number, 1)

    task_group_model = FakeTaskGroup.objects.create()
    task_model = FakeTask.objects.create(task_group=task_group_model)
    add_one(task_model.id)
    task_model.refresh_from_db()
    self.assertEqual(task_model.task_group.finished_tasks_number, 1)
}}}

Here you can find the definition (light version) of the this models:

{{{
class FakeTaskGroup(models.Model):
   finished_tasks_number = models.PositiveIntegerField(default=0)

class FakeTask(models.Model):
    task_group = models.ForeignKey(FakeTaskGroup, on_delete=models.CASCADE)
}}}
"	Bug	closed	Database layer (models, ORM)	2.0	Normal	wontfix	refresh_from_db		Unreviewed	0	0	0	0	0	0