from rest_framework import serializers from .models import BudgetGroup, BudgetLine class BudgetGroupSerializer(serializers.ModelSerializer): total = serializers.SerializerMethodField() def get_total(self, obj): tot = 0 for i in obj.budgetline_set.all(): tot += i.amount return tot class Meta: model = BudgetGroup fields = "__all__" class BudgetLineSerializer(serializers.ModelSerializer): class Meta: model = BudgetLine fields = "__all__"