how to use reverse query data from a child model to do arithmetic's in parent model?

[Vansh Jagyasi -IIITK]

I have created a model location, and a model transaction which has a many to one relation with location which has the information of a transaction done at a particular location, say 3 dollars spent at macdonalds, now I want to find all the transactions related to a particular location and add the amount to find the total amount spent,please help

[Ryan Nowakowski]

You probably want to use `Sum` from Django aggregate:

https://docs.djangoproject.com/en/3.1/topics/db/aggregation/