How to get only latest record on filter of foreign key

Question

I have a table like this

Event table

id	status	date	order(FK)
1	Planned	05-02-2015	1
2	Delivered	04-02-2015	2
3	Packed	03-02-2015	3
4	Return	06-02-2015	1

I want output like this

id	status	date	order(FK)
2	Delivered	04-02-2015	2
3	Packed	03-02-2015	3
4	Return	06-02-2015	1

I tried with

query = Event.objects.annotate(order_num=Max('date'))

but didn't get the expected result. How can I achieve this output?

Answer 1

Try using the following:

from django.db.models import Max

Event.objects.annotate(max_date=Max('order__event__date')) \
             .filter(date=F('max_date'))