#34933: update_or_create() does not persist field changes in save() when 
performing
an update
-------------------------------------+-------------------------------------
               Reporter:  cbasah     |          Owner:  nobody
                   Type:  Bug        |         Status:  new
              Component:  Database   |        Version:  4.2
  layer (models, ORM)                |
               Severity:  Normal     |       Keywords:  update_or_create
           Triage Stage:             |      Has patch:  0
  Unreviewed                         |
    Needs documentation:  0          |    Needs tests:  0
Patch needs improvement:  0          |  Easy pickings:  0
                  UI/UX:  0          |
-------------------------------------+-------------------------------------
 It seems when ''update_or_create()'' is updating an object, field updates
 set in the model's overriden ''save()'' method is not persisted in the
 database.

 The following simple model illustrates this behavior. ''field1'' is set
 via the ''default={...}'' argument while ''field2'' is an increment of
 ''field1'' by 1 performed in the model's overridden ''save()'' method.

 {{{#!python
 class Test(models.Model):
     field1 = models.PositiveSmallIntegerField(blank=True, null=True)
     field2 = models.PositiveSmallIntegerField(blank=True, null=True)

     def save(self, *args, **kwargs):
         self.field2 = self.field1 + 1
         super().save(*args, **kwargs)
 }}}

 The following call for ''update_or_create()'' '''inserts''' the object
 with id 1
 {{{#!python
 >>> (obj, is_created) = Test.objects.update_or_create(id=1,
 defaults={'field1': 1})
 >>> Test.objects.get(id=1).field1
 1
 >>> Test.objects.get(id=1).field2
 2
 }}}

 The following call '''updates''' the same object
 {{{#!python
 >>> (obj, is_created) = Test.objects.update_or_create(id=1,
 defaults={'field1': 10})
 >>> Test.objects.get(id=1).field1
 10
 >>> Test.objects.get(id=1).field2
 2
 }}}
 However, field2 does not get updated to 11.

-- 
Ticket URL: <https://code.djangoproject.com/ticket/34933>
Django <https://code.djangoproject.com/>
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