Django，从带注释的最大值中选择一个最大值(几个字段中的最大值)

Question

我有一个关于 django 注释方法的问题:
是否可以计算这 3 个特定折扣的“maximum_discount”(并按此“maximum_discount”排序)？

Product.objects\
   .annotate(
        product_discount=Max('discounts__amount'),
        category_discount=Max('category__discounts__amount'),
        brand_discount=Max('brand__discounts__amount')
    )

Answer 1

尝试这样的事情:

max_discount = max(value for key, value in Product.objects\
   .annotate(  # maybe 'aggregate'?
        product_discount=Max('discounts__amount'),
        category_discount=Max('category__discounts__amount'),
        brand_discount=Max('brand__discounts__amount')
    )
)