#25982: Djago ORM. Filter using multi-valued queryset
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Reporter: FreddieFruitSticks | Owner: nobody
Type: New feature | Status: new
Component: Database layer | Version: 1.8
(models, ORM) | Keywords: mutli-value,
Severity: Normal | valuequeryset
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
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As I understand it, and from the error I received, trying to filter based
on a multi-valued queryset cant be done (the error I received was
something like "cant filter using multi-valued querysets"). It is possible
that one may wish to filter based on a pair of values. Commutativity of
the tuples should be considered. Eg Filter the following:
Object.objects.values_list("v1","v2").filter(AnotherObject.objects.values_list("v1","v2"))
Eg,
[(1,2),(5,7),(3,8),(9,3)].filter ([(1,2),(3,9)]) = [(5,7),(3,8),(9,3)]
here (9,3) == (3,9) is false. Non-commutative
For commutative comparison we have Eg,
[(1,2),(5,7),(3,8),(9,3)].filter ([(1,2),(3,9)]) = [(5,7),(3,8)]
here (9,3) == (3,9) is true.
The non-commutative case was necessary in an example I had. I hacked it
where I created lists and compared using lists. However this requires a db
evaluation.
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Ticket URL: <https://code.djangoproject.com/ticket/25982>
Django <https://code.djangoproject.com/>
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