'decimal.Decimal‘对象不可迭代django出错

Question

我在尝试循环并获取Django模型中的一个十进制对象的总数时遇到错误，尝试了这么多解决方案都失败了。错误是

'decimal.Decimal' object is not iterable

这是模型和对象。

from django.db import models

class Product(models.Model):
    name = models.CharField(max_length=50, null=True)
    price = models.DecimalField(max_digits=6, decimal_places=2)

    def __str__(self):
        return self.name

class Order(models.Model):
    total_price = models.DecimalField(max_digits=10, decimal_places=2, default=0)
    timestamp = models.DateTimeField(auto_now=True)

    def __str__(self):
        return 'Order {0}'.format(self.id)

    @property
    def order_prices(self):
        order = Decimal(0)
        for o in float(self.total_price):
            order += o
        return float(order)


    @property
    def product_name(self):
        product_name = []
        for b in self.orderitem_set.all():
            product_name.append(b.total_name)
        return product_name
        
class OrderItem(models.Model):
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    order = models.ForeignKey(Order, on_delete=models.CASCADE)
    timestamp = models.DateTimeField(auto_now=True)

    @property
    def total_name(self):
        product_name = []
        for p in self.product.name:
            product_name.append(p)
        b = "".join(product_name)
        return b

错误发生在订单模型的order_price对象上

Answer 1

@property
def order_prices(self):
    queryset = self.orderitem_set.all().aggregate(
        total_price=models.Sum('product__price'))
    return queryset['total_price']