[Django]-Django queryset question

You’ll need to add error checking but you could do something like this logic-wise:

total = 0
cart_items = CartItem.objects.filter(ticket__event=event) # assuming there are multiple cart items per event
for cart_item in cart_items:
    new_total = cart_item.ticket.price * cart_item.quantity
    total = total + new_total

That should give you total revenue for an event.