#29367: bulk_create with manual primary_key don't update instances state
-------------------------------------+-------------------------------------
Reporter: Oscar | Owner: nobody
Esgalha |
Type: Bug | Status: new
Component: Database | Version: master
layer (models, ORM) | Keywords: bulk_create,
Severity: Normal | primary_key
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
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Given a model with manually defined primary keys:
{{{
#!python
class State(models.Model):
two_letter_code = models.CharField(max_length=2, primary_key=True)
}}}
Performing a bulk_create with model instances will not correctly update
their state.
Looping through the instances and calling save() individually will result
in instances with different state from instances persisted with
bulk_create:
{{{
#!python
state_ca = State(two_letter_code='CA')
State.objects.bulk_create([state_ca])
state_ca._state.adding # => True
state_ca._state.db # => None
state_ny = State(two_letter_code='NY')
state_ny.save()
state_ny._state.adding # => False
state_ny._state.db # => 'default'
}}}
One implication of this behavior is that the instances saved with
bulk_create can't be used to build relationships with model instances
loaded with other Queryset API methods.
Here is a demonstration:
{{{
#!python
class Group(models.Model):
ext_id = models.CharField(primary_key=True, max_length=32)
class Analist(models.Model):
ext_id = models.CharField(primary_key=True, max_length=32)
groups = models.ManyToManyField(Group)
group_aaa = Group.objects.get(ext_id='AAA')
analist_eee = Analist(ext_id='EEE')
Analist.objects.bulk_create([analist_eee])
analist_eee.groups.set([group_aaa]) # ValueError: Cannot add "<Group:
AAA>": instance is on database "None", value is on database "default"
}}}
It fails when the `._state.db` is compared.
A current workaround option is to manually set the `._state.db` after the
bulk_create:
{{{
analist_eee = Analist(ext_id='EEE')
Analist.objects.bulk_create([analist_eee])
analist_eee._state.db = 'default'
analist_eee.groups.set([group_aaa]) # And now it works
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/29367>
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