How to sum data from an annotated query - django

Question

I'm trying to create a report that shows the number of males, females, and total customers in a given day by hour.
The data is inserted into the database as a transaction whenever somebody enters the building. It stores their gender there.
The query to gather the data looks as follows:
initial_query = EventTransactions.objects.using('reportsdb')
.filter(building_id=id,
actualdatetime__lte=end_date,
actualdatetime__gte=beg_date)
From there, I annotate the query to extract the date:
ordered_query = initial_query.annotate(
year=ExtractYear('actualdatetime'),
month=ExtractMonth('actualdatetime'),
day=ExtractDay('actualdatetime'),
hour=ExtractHour('actualdatetime'),
male=Coalesce(Sum(Case(When(customer_gender='M', then=1)), output_field=IntegerField()), Value(0)),
female=Coalesce(Sum(Case(When(customer_gender='F', then=1)), output_field=IntegerField()), Value(0))
).values(
'year', 'month', 'day', 'hour', 'male', 'female'
)
How do I then sum the male customers and female customers by hour?
By this, I mean that I wish to provide a table to the user which contains each hour of the day (can just be a number from 0-23 at this point), total males for that hour, total females for that hour, and total customers for that hour:
TIME | MALE | FEMALE | TOTAL
0 12 4 16
1 5 8 13
2 2 3 5
3 20 38 58
etc.
I'd be happy to provide more information if necessary. Thank you!

Answer 1

You're nearly there. Do the annotation for the gendered populations after calling values such that the database will do the aggregate on the group of datetime extracted values.
ordered_query = initial_query.annotate(
year=ExtractYear('actualdatetime'),
month=ExtractMonth('actualdatetime'),
day=ExtractDay('actualdatetime'),
hour=ExtractHour('actualdatetime'),
).values(
'year', 'month', 'day', 'hour',
).annotate(
male=Coalesce(Sum(Case(When(customer_gender='M', then=1)), output_field=IntegerField()), Value(0)),
female=Coalesce(Sum(Case(When(customer_gender='F', then=1)), output_field=IntegerField()), Value(0))
)