[Solved]-Django annotate whether exists or not

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You can make use of an Exists expression [Django-doc] to determine if there exists a Pet for that Person. For example:

from django.db.models import Exists, OuterRef

Person.objects.annotate(
    has_pet=Exists(Pet.objects.filter(person=OuterRef('pk')))
)

Here the model is thus Pet that has a ForeignKey named person to Person. If the fields are named differently, then you should of course update the query accordingly.

👤willeM_ Van Onsem

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