Django管理列表显示优化查询集

Question

在User模型中我有一个方法:

@cached_property
    def income(self):
        return PartnerIncome.objects.all().aggregate(Sum('income'))['income__sum']*self.share_of_profit

PartnerIncome模型:

class PartnerIncome(models.Model):
    title = models.CharField(max_length=255)
    income = models.FloatField(default=0)

现在我想list_display=('income', )在管理面板中显示'inccome' ,但每个对象都会对数据库进行额外查询.我如何PartnerIncome.objects.all().aggregate(Sum('income'))作为管理员更改列表的全局变量...

Answer 1

如何覆盖get_queryset你的方法ModelAdmin呢？

class UserAdmin(admin.ModelAdmin):

    list_display = ('income', ...)

    def income(self, obj):
        return obj.income

    def get_queryset(self, request):
       queryset = super(UserAdmin, self).get_queryset(request)
       # you logic here to `annotate`the queryset with income
       return queryset

文档aggregation:

https://docs.djangoproject.com/en/dev/topics/db/aggregation/

没有我真正理解你的模型和业务逻辑..这里是我自己的代码的一个片段作为一个例子:

class AuthorAdmin(admin.ModelAdmin):
    list_display = ('__str__', 'books_count',)

    def books_count(self, obj):
        return obj.books_count

    def get_queryset(self, request):
        return super(AuthorAdmin, self).get_queryset(
            request).annotate(books_count=Count('books'))