.annotate() and .values()

[mr-time2028]

Is django jalali only support .filter() query?
it might be great if you add a feature to support .values() and .annotate() queries.

[hramezani]

Could you please explain it more?

What do you mean by add a feature to support .values() and .annotate() queries.? Could you please provide some examples?

[mr-time2028]

I'm using .values("timestamp__year") query for my database records to get jalali year for each of them, but it return gregorian year instead.

[hramezani]

Ok, We don't support it for now. as you know, Django converts __year to django_date_extract and does the year extraction at the database level. for example, it converts .values("timestamp__year") to SELECT django_date_extract('year', "model_name"."timestamp") FROM ....
One possible solution would be to override def values(self, *fields, **expressions): and then search for __year and the end of fields and convert the year from gregorian to jalali. but I am not sure about the performance because we have to loop over all data.
The other solution is, to convert years at the database level by changing django_date_extract but I think this one is hard to implement.

Do you have any idea here @slashmili?

[mr-time2028]

finally I got jalali year by another way, I try .values("timestamp") instead of .values("timestamp__year") and it return jalali datetime (timestamp is a jDateTimeField). then I get jalali year by this line of code:

queryset = my_model.objects.values("timestamp")
for query in queryset:
    jalali_year = query['timestamp'].year
    ....

so because it worked, actually we can use of it for other lookups. but as a side note, actually I don't know Is it work for jDateField or not?

About .annotate() we need something like jalali Extract class.