Is it possible to refresh the state of a django object from database? I mean behavior roughly equivalent to:
new_self = self.__class__.objects.get(pk=self.pk) for each field of the record: setattr(self, field, getattr(new_self, field))
UPDATE: Found a reopen/wontfix war in the tracker: http://code.djangoproject.com/ticket/901.
Still don’t understand why the maintainers don’t like this.
I’ve found it relatively easy to reload the object from the database like so:
x = X.objects.get(id=x.id)
In reference to @grep’s comment, shouldn’t it be possible to do:
# Put this on your base model (or monkey patch it onto django's Model if that's your thing) def reload(self): new_self = self.__class__.objects.get(pk=self.pk) # You may want to clear out the old dict first or perform a selective merge self.__dict__.update(new_self.__dict__) # Use it like this bar.foo = foo assert bar.foo.pk is None foo.save() foo.reload() assert bar.foo is foo and bar.foo.pk is not None
As of Django 1.8 refreshing objects is built in. Link to docs.
def test_update_result(self): obj = MyModel.objects.create(val=1) MyModel.objects.filter(pk=obj.pk).update(val=F('val') + 1) # At this point obj.val is still 1, but the value in the database # was updated to 2. The object's updated value needs to be reloaded # from the database. obj.refresh_from_db() self.assertEqual(obj.val, 2)
As @Flimm pointed out, this is a really awesome solution:
This reloads all data from the database into the object.