[Django] #28253: Integrity error in get_or_create
Django
-------------------------------------+-------------------------------------
Reporter: Anuranjit | Owner: Anuranjit maindola
maindola |
Type: Bug | Status: assigned
Component: Database | Version: 1.11
layer (models, ORM) |
Severity: Normal | Keywords:
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
I came across an issue. Consider a code example below
{{{
class Config(models.Model):
key = models.CharField(max_length=100)
value = models.CharField(max_length=100)
def save(self, *args, **kwargs):
super(Config, self).save(*args, **kwargs)
super(Config, self).save(*args, **kwargs)
}}}
Now if for the Above model I do
{{{
params = {"key":"1", "value": "2")
obj, created = Config.objects.get_or_create(**params)
}}}
I get an Integrity Error for Primary Key i.e. the database `id` field.
The issue as i understood comes because Django tries to insert again with
duplicate Primary key. In `get_or_create` the `create` method is called
with `force_insert=True` and a particular check in `_save_table` fails
(line number 897) . (If this check passes django is supposed to do an
update).
{{{
# If possible, try an UPDATE. If that doesn't update anything, do an
INSERT.
if pk_set and not force_insert:
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/28253>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
-------------------------------------+-------------------------------------
| maindola
Type: Bug | Status: assigned
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Old description:
> I came across an issue. Consider a code example below
> {{{
> class Config(models.Model):
> key = models.CharField(max_length=100)
> value = models.CharField(max_length=100)
> def save(self, *args, **kwargs):
> super(Config, self).save(*args, **kwargs)
> super(Config, self).save(*args, **kwargs)
> }}}
> Now if for the Above model I do
> {{{
> params = {"key":"1", "value": "2")
> obj, created = Config.objects.get_or_create(**params)
> }}}
> I get an Integrity Error for Primary Key i.e. the database `id` field.
>
> The issue as i understood comes because Django tries to insert again with
> duplicate Primary key. In `get_or_create` the `create` method is called
> with `force_insert=True` and a particular check in `_save_table` fails
> (line number 897) . (If this check passes django is supposed to do an
> update).
>
> {{{
> # If possible, try an UPDATE. If that doesn't update anything, do an
> INSERT.
> if pk_set and not force_insert:
> }}}
New description:
I came across an issue. Consider a code example below
{{{
class Config(models.Model):
key = models.CharField(max_length=100)
value = models.CharField(max_length=100)
def save(self, *args, **kwargs):
super(Config, self).save(*args, **kwargs)
super(Config, self).save(*args, **kwargs)
}}}
Now if for the Above model I do
{{{
params = {"key":"1", "value": "2"}
obj, created = Config.objects.get_or_create(**params)
}}}
I get an Integrity Error for Primary Key i.e. the database `id` field.
The issue as i understood comes because Django tries to insert again with
duplicate Primary key. In `get_or_create` the `create` method is called
with `force_insert=True` and a particular check in `_save_table` fails
(line number 897) . (If this check passes django is supposed to do an
update).
{{{
# If possible, try an UPDATE. If that doesn't update anything, do an
INSERT.
if pk_set and not force_insert:
}}}
--
Comment (by Tim Graham):
What's the reason for calling `super().save()` twice?
--
Ticket URL: <https://code.djangoproject.com/ticket/28253#comment:1>
Django
-------------------------------------+-------------------------------------
Type: Bug | Status: assigned
Component: Database layer | Version: 1.11
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* owner: Anuranjit maindola => 冯钊
--
Ticket URL: <https://code.djangoproject.com/ticket/28253#comment:2>
Django
-------------------------------------+-------------------------------------
| maindola
Type: Bug | Status: assigned
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage:
| Unreviewed
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* owner: 冯钊 => Anuranjit maindola
--
Ticket URL: <https://code.djangoproject.com/ticket/28253#comment:3>
Django
-------------------------------------+-------------------------------------
| maindola
Component: Database layer | Version: 1.11
(models, ORM) |
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* status: assigned => closed
* resolution: => invalid
Comment:
Absent a justification for the double save, this looks like invalid usage
rather than a bug in Django.
--
Ticket URL: <https://code.djangoproject.com/ticket/28253#comment:2>
Django
-------------------------------------+-------------------------------------
| maindola
Type: Bug | Status: closed
Component: Database layer | Version: 1.11
(models, ORM) |
Severity: Normal | Resolution: invalid
Keywords: | Triage Stage:
| Unreviewed
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Anuranjit maindola):
@Tim Graham .
Doing any number of saves should be fine.
Can you elaborate on why is this is not a valid issue?
--
Ticket URL: <https://code.djangoproject.com/ticket/28253#comment:3>
Django
-------------------------------------+-------------------------------------
| maindola
Type: Bug | Status: closed
Component: Database layer | Version: 1.11
(models, ORM) |
Severity: Normal | Resolution: invalid
Keywords: | Triage Stage:
| Unreviewed
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Marten Kenbeek):
The issue is that you save twice with `force_insert=True`, without
changing the value of the primary key. If you want to update the object
after the first save, you need to strip the `force_insert` argument from
`**kwargs`.
--
Ticket URL: <https://code.djangoproject.com/ticket/28253#comment:4>