Django 中的通用关系，带有聚合的查询集

Question

我在模型中使用 django 1.6 和通用关系。我对模型中的 aggregate 函数有疑问：

以下是我的部分观点：

class EventListView(PageContextMixin, ListView):
    model = Activity
    template_name = 'events/eventlist.html'

    def get_queryset(self):
        seasons = Season.objects.all()
        if not self.request.user.is_superuser:
            seasons = seasons.filter(is_active=True)
            active_seasons_ids = list(IsActiveFlag.objects.exclude(is_active=False).values_list('id', flat=True))
            seasons = list(Season.objects.filter(isactiveflags__id__in=active_seasons_ids))
        minmax = seasons.aggregate(Min('start'), Max('end'))
        min_date = minmax['start__min']
        max_date = minmax['end__max']

        active_sale_and_cycles_ids = list(SaleAndCycle.objects.exclude(is_sale_active=False).values_list('id', flat=True))
        filters_sale = Q(sale_and_cycles__id__in=active_sale_and_cycles_ids)
        active_is_cyclic_event_ids = list(SaleAndCycle.objects.exclude(is_cyclic_event_active=False).values_list('id', flat=True))
        filters_cycle = Q(sale_and_cycles__id__in=active_is_cyclic_event_ids)
        sales_events_activities = Activity.objects.filter(Q(filters_sale, online=True) | Q(filters_cycle, online=True))   
        sales_events_ids = sales_events_activities.values_list('id', flat=True)
        minmax_sales_events_activities = sales_events_activities.aggregate(Min('start'), Max('end'))
        max_date_sales_events_activities = minmax_sales_events_activities['end__max']

我在这个地方遇到错误：

minmax_sales_events_activities = sales_events_activities.aggregate(Min('start'), Max('end'))

错误：

no such table: events_saleandcycle

但是数据库（我使用sqlite）中有table字段：id, content_type_id, object_id, position, is_sale_active, is_cyclic_event_active , cycle_link

class SaleAndCycle(SortableVAExtra):
    is_sale_active = models.BooleanField(default=False)
    is_cyclic_event_active = models.BooleanField(default=False)
    cycle_link = models.CharField(max_length=255, null=True, blank=True)

    def __unicode__(self):
        return str(self.is_sale_active)

Answer 1

有一个 closed issue against Django 1.6 that describes failures of annotations (aggregations). The relevant commit 修复仅存在于 Django 1.7a 向上。

恐怕你唯一的机会就是升级到 Django 1.7。

Django 中的通用关系，带有聚合的查询集

Generic relation in django, queryset with aggregate

python

django

aggregate

django-1.6

django-generic-relations