python - 聚合数据时无法获取 的 repr

Question

@user_passes_test(lambda u: u.is_staff, login_url='/pyramid/login/')
def defaulters_report(request):
    template = 'private/admin/report_defaulters.html'
    queryset = list(TreeNode.objects.all())
    for x in queryset:
        x.d = x.debt
    defaulters = TreeNode.objects.filter(id__in=([x.id for x in queryset if x.d > 0]))
    context = dict()
    unpaid_purepro = defaulters[0].annuities.all()
    for x in list(defaulters)[1:]:
        unpaid_purepro = unpaid_purepro | x.annuities.all()
    unpaid_purepro = unpaid_purepro.filter(expected_date__lt=timezone.now())
    context['total'] = unpaid_purepro.all().aggregate(Sum('total'))['total__sum']
    return render(request, template, context)

当我尝试获取 unpaid_purepro 的值时 - 我收到问题标题中的错误。 View 的最终错误是:

Expression tree is too large (maximum depth 1000)

我哪里错了？

换句话说:对于每个具有最后 expected_date 的 TreeNode FilterPayment 应该被选择并且 TreeNodes 应该按它们的 payment__expected_date 排序

更新:

模型.py:

class TreeNode(MPTTModel):
    class Meta:
        verbose_name = 'участник'
        verbose_name_plural = 'участники'

    # account for auth

    account = models.OneToOneField(User, verbose_name='аккаунт', related_name='treenode')

    @property
    def debt(self):
        ...

    @property
    def last_payment(self):
        return self.annuities.last()

    @property
    def pay_progress(self):
        return "{}/{}".format(self.annuities.exclude(fact_date=None).aggregate(Sum('total'))['total__sum'],
                             self.annuities.aggregate(Sum('total'))['total__sum'])


class FilterPayment(models.Model):
    class Meta:
        verbose_name = 'взнос за фильтр'
        verbose_name_plural = 'взносы за фильтр'

    expected_date = models.DateField(verbose_name='ожидаемая дата')
    fact_date = models.DateField(verbose_name='фактическая дата', null=True, blank=True)
    total = models.IntegerField(verbose_name='сумма')
    client = models.ForeignKey(TreeNode, related_name='annuities', verbose_name='клиент')

    CASH = 1
    TERMINAL = 2

    METHOD_CHOICES = (
        (CASH, "Cash"),
        (TERMINAL, "Mobilnik")
    )
    method = models.PositiveSmallIntegerField(choices=METHOD_CHOICES, default=1)

Answer 1

你会得到这个错误，因为一些生成的 SQL 查询对于 SQLite 来说太大了。如果您需要 annuities 与 treenodes 的过去 expected_date 以及正 debt 的总和，您可以试试这个:

@user_passes_test(lambda u: u.is_staff, login_url='/pyramid/login/')
def defaulters_report(request):
    template = 'private/admin/report_defaulters.html'
    context = {}

    context['total'] = TreeNode.objects.filter(
        debt__gt=0,
        annuities__expected_date__lt=timezone.now()
    ).aggregate(total=Sum('annuities__total'))['total']

    return render(request, template, context)

文档:

• Executing queries
• Aggregation