Reference to aggregated field AND double underscore notation results in bad SQL

[Vasily Ivanov]

I have simple model like this one:

class Plan(models.Model):
	cap = models.IntegerField()

class Phone(models.Model):
	plan = models.ForeignKey(Plan, related_name='phones')

class Call(models.Model):
	phone = models.ForeignKey(Phone, related_name='calls')
	cost = models.IntegerField()

Call to:

Phone.objects.annotate(total_cost=Sum('calls__cost')).filter(total_cost__gte=0.5*F('plan__cap'))

results in error:

ProgrammingError: column "app_plan.cap" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: ...."plan_id" HAVING SUM("app_call"."cost") >=  0.5 * "app_plan"....

Generated SQL is:

SELECT "app_phone"."id", "app_phone"."plan_id", SUM("app_call"."cost") AS "total_cost"
FROM "app_phone"
INNER JOIN "app_plan" ON ("app_phone"."plan_id" = "app_plan"."id")
LEFT OUTER JOIN "app_call" ON ("app_phone"."id" = "app_call"."phone_id")
GROUP BY "app_phone"."id", "app_phone"."plan_id"
HAVING SUM("app_call"."cost") >=  0.5 * "app_plan"."cap"

Is it Django bug?

[Vasily Ivanov]

I don't know how to modify ticket description here, but in case someone can see ambiguity here I'd like Django to add "app_plan"."cap" column into GROUP BY clause in this particular case.

[Vasily Ivanov]

Workaround:
​http://stackoverflow.com/questions/2755382/need-a-workaround-to-filter-on-related-model-and-aggregated-fields-in-django/2761578#2761578

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Anssi Kääriäinen]

This seems to be fixed in master, see aggregation_regress/test_aggregate_fexpr()