class SampleModel(models.Model):
date = models.DateField()
value = models.IntegerField()
subquery = SampleModels.objects.filter(
date__gte=models.OuterRef('date') - timedelta(days=2),
date__lte=models.OuterRef('date') + timedelta(days=2),
value__lte=30
)
queryset = SampleModel.objects.annotate(
is_what_i_am_looking_for=models.Exists(subquery)
)
According to the documentation on OuterRef
<https://docs.djangoproject.com/en/2.0/ref/models/expressions/#referencing-columns-from-the-outer-queryset>
:
Use OuterRef when a queryset in a Subquery needs to refer to a field from
> the outer query. It acts like an F
> <https://docs.djangoproject.com/en/2.0/ref/models/expressions/#django.db.models.F>
> expression
> except that the check to see if it refers to a valid field isn’t made until
> the outer queryset is resolved.
Since it states that it acts "like" an F expression, I assumed that
utilizing a timedelta would be permissible. However, I receive the
following traceback:
AttributeError: 'ResolvedOuterRef' object has no attribute 'relabeled_clone'
I was able to find someone else that is having this problem on
StackOverflow
<https://stackoverflow.com/questions/48230771/is-it-possible-to-do-arithmetic-operation-on-outerref-expression>.
I would like to confirm whether this is a bug or a lack of clarification in
the documentation. F expressions allow operations such as timedelta on
DateField.
Thanks for your help/advice in advance!
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