I have a model where I can set expire_date_1 and expire_date_2. And 2 filters like this.
filter_1 = Q(expire_date_1__isnull=False) & Q(expire_date_1__lte=after_30days)
filter_2 = Q(expire_date_2__isnull=False) & Q(expire_date_2__lte=after_30days)
I want to filter the model that if expire_date_2 is not null then using filter_2 else use filter_1 I tried it to do with Case and When but I can't filter in a When function, can I?
You can work with Coalesce [Django-doc] to determine what field to use:
from django.db.models import Coalesce
MyModel.objects.alias(
exp_date=Coalesce('expire_date_2', 'expire_date_1')
).filter(
exp_date__lte=after_30_days
)or prior to django-3.2 with .annotate(…):
from django.db.models import Coalesce
MyModel.objects.annotate(
exp_date=Coalesce('expire_date_2', 'expire_date_1')
).filter(
exp_date__lte=after_30_days
)