問題描述

models.py：訂單數據模型

class Order(models.Model): date = models.DateTimeField(default=timezone.now) paid_card = models.PositiveIntegerField(blank=True, null=True) paid_cash = models.PositiveIntegerField(blank=True, null=True) paid_gift = models.PositiveIntegerField(blank=True, null=True)statur = models.CharField() @property # 實收金額(paid_in) = paid_card + paid_cash + paid_gift def paid_in(self):return sum(filter(None, [self.paid_card, self.paid_cash, self.paid_gift]))

views.py: 按日歸檔統計每天的訂單數、訂單總額

def wx_archive(request): orders = Order.objects.filter(status=’closed’).annotate(day=TruncDay(’start_time’)).values(’day’).annotate(count=Count(’id’), total=Sum(’paid_in’)).values(’day’, ’count’, ’total’).order_by(’day’) return render(request, ’orders/archive.html’, {’orders’: orders})

運行后報錯，提示

FieldError at /orders/archive/Cannot resolve keyword ’paid_in’ into field. Choices are: count, day, id, paid_card, paid_cash, paid_gift, status

請問，我該如何統計每日的總 paid_in？

問題解答

你的paid_in并不是數據庫字段，很明顯不能用在SQL語句中。兩個方法：

把符合時間段的orders實例取出來，用時間篩選。然后Sum(所有的order.pard_in)

數據庫層面Sum所有符合時間段的訂單的paid_card, paid_cash, paid_gift