#29291: Conditional expressions and ~Q queries
-------------------------------------+-------------------------------------
Reporter: Bo Marchman | Owner: nobody
Type: Bug | Status: new
Component: Database layer | Version: 2.0
(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
-------------------------------------+-------------------------------------
Description changed by Bo Marchman:
Old description:
> I've run into an issue with conditional expressions using negated Q
> objects.
>
> I would expect `qs1` and `qs2` to be equivalent in the following code:
>
> {{{#!python
>
> class Application(models.Model):
> pass
>
> class Score(models.Model):
> application = models.ForeignKey(Application,
> on_delete=models.PROTECT)
> reviewed = models.BooleanField()
>
> a1 = Application.objects.create()
> Score.objects.create(reviewed=False, application=a1)
> Score.objects.create(reviewed=True, application=a1)
>
> a2 = Application.objects.create()
>
> qs1 = Application.objects.annotate(
> needs_review=Case(
> When(~Q(score__reviewed=True), then=V(True)),
> default=V(False),
> output_field=BooleanField()
> )
> ).filter(needs_review=True)
>
> qs2 = Application.objects.filter(
> ~Q(score__reviewed=True)
> )
>
> print(qs1) # <QuerySet [<Application: Application object (1)>,
> <Application: Application object (2)>]>
> print(qs2) # <QuerySet [<Application: Application object (2)>]>
>
> assert set(qs1) == set(qs2)
> }}}
>
> The identical `~Q` expression is behaving differently in the context of
> `Case/When` and `filter`. Am I completely missing something and this is
> expected behavior?
New description:
I've run into an issue with conditional expressions using negated Q
objects.
I would expect `qs1` and `qs2` to be equivalent in the following code:
{{{#!python
class Application(models.Model):
pass
class Score(models.Model):
application = models.ForeignKey(Application, on_delete=models.PROTECT)
reviewed = models.BooleanField()
a1 = Application.objects.create()
Score.objects.create(reviewed=False, application=a1)
Score.objects.create(reviewed=True, application=a1)
a2 = Application.objects.create()
qs1 = Application.objects.annotate(
needs_review=Case(
When(~Q(score__reviewed=True), then=V(True)),
default=V(False),
output_field=BooleanField()
)
).filter(needs_review=True)
qs2 = Application.objects.filter(
~Q(score__reviewed=True)
)
print(qs1) # <QuerySet [<Application: Application object (1)>,
<Application: Application object (2)>]>
print(qs2) # <QuerySet [<Application: Application object (2)>]>
assert set(qs1) == set(qs2)
}}}
The identical `~Q` expression is behaving differently in the context of
`Case/When` and `filter`. Am I completely missing something and this is
expected behavior?
This is using Django 2.0.4.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/29291#comment:1>
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