'We can increment a value of all objects in a query set.'

def test_increment_value(self):

    self.assertEqual(Number.objects.filter(integer__gt=0).update(integer=(F('integer') + 1)), 2)
    self.assertQuerysetEqual(Number.objects.all(), ['<Number:    -1,    -1.000>', '<Number:    43,    42.000>', '<Number:    1338,    1337.000>'], ordered=False)
