I get an error when return a queryset objects: Cannot resolve expression type, unknown output_field

Question

I'm need annotation each object in queryset. I used annotation, but when return modified object, I get this error:

Cannot resolve expression type, unknown output_field.

How can I solve this problem?

def get_queryset(self):
   get_cinema = Ciname.objects.filter(active_cinema='t')
   distation = 54.87 #for example
   queryset = get_cinema.annotate(distance=models.Max(distation))
   return queryset

Answer 1

You might need to add an output_field to your annotation:

queryset = get_cinema.annotate(distance=models.Max(distation, output_field=models.FloatField()))