#29291: Conditional expressions and ~Q queries
-------------------------------------+-------------------------------------
Reporter: Bo Marchman | Owner: nobody
Type: Bug | Status: new
Component: Database layer | Version: master
(models, ORM) |
Severity: Normal | Resolution:
Keywords: | Triage Stage: Accepted
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by rjsparks):
I think this is just a consequence of the way annotate works on a reverse
ForeignKey rather than being a bug in the conditional expression.
{{{
In [53]: Application.objects.annotate(
...: needs_review=Case(
...: When(~Q(score__reviewed=True), then=V(True)),
...: default=V(False),
...: output_field=BooleanField()
...: )
...: )
Out[53]: <QuerySet [<Application: Application object (1)>, <Application:
Application object (1)>, <Application: Application object (2)>]>
In [54]: Application.objects.annotate(
...: needs_review=Case(
...: When(~Q(score__reviewed=True), then=V(True)),
...: default=V(False),
...: output_field=BooleanField()
...: )
...: ).values_list('needs_review',flat=True)
Out[54]: <QuerySet [True, False, True]>
}}}
Or more simply:
{{{
In [55]:
Application.objects.annotate(score_has_been_reviewed=F('score__reviewed
...: '))
Out[55]: <QuerySet [<Application: Application object (1)>, <Application:
Application object (1)>, <Application: Application object (2)>]>
In [56]:
Application.objects.annotate(score_has_been_reviewed=F('score__reviewed
...: ')).values_list('score_has_been_reviewed',flat=True)
Out[56]: <QuerySet [False, True, None]>
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/29291#comment:5>
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