Django |是否根据单项价格和金额生成总价？

# models.py
from django.db import models

class Product(models.Model):
    name = models.CharField(max_length=100)
    price = models.DecimalField(max_digits=8, decimal_places=2)

class Order(models.Model):
    products = models.ManyToManyField(Product)
    total_price = models.DecimalField(max_digits=10, decimal_places=2)

    def calculate_total_price(self):
        total = sum(product.price for product in self.products.all())
        self.total_price = total
        self.save()

# views.py
from django.shortcuts import render
from .models import Order

def order_detail(request, order_id):
    order = Order.objects.get(id=order_id)
    order.calculate_total_price()
    return render(request, 'order_detail.html', {'order': order})