Question

我有3个模特

class Lease(CommonInfo):
    version = IntegerVersionField( )
    #amount  = models.DecimalField(max_digits=7, decimal_places=2)
    is_renewed = models.BooleanField(default=False)
    unit = models.ForeignKey(Unit)
    is_terminated = models.BooleanField(default=False)

class LeaseTerm(CommonInfo):
    version = IntegerVersionField( )
    start_period = models.ForeignKey(Period, related_name='start_period' )
    end_period = models.ForeignKey(Period, related_name='end_period')
    lease = models.ForeignKey(Lease)
    increase  = models.DecimalField(max_digits=7, decimal_places=2)
    amount  = models.DecimalField(max_digits=7, decimal_places=2)
    is_terminated = models.BooleanField(default=False)

    def clean(self):
    model = self.__class__
    if self.lease_id and (self.is_terminated == False) and model.objects.filter(lease=self.lease, is_active=True ).count() == 1:
        raise ValidationError('!Lease has a active condition already, Terminate prior to creation of new one'.format(self.lease))

class LeasePayment(CommonInfo):
    version = IntegerVersionField( )
    amount  = models.DecimalField(max_digits=7, decimal_places=2)
    leaseterm = models.ForeignKey(LeaseTerm)
    period_payed_for = models.DateTimeField()
    payment_date = models.DateTimeField()

（clean方法只允许一个LeaseTerm处于活动状态而不会终止。）

在我看来，我希望看到为此租约活跃的LeaseTerm所做的所有付款

    lease = get_object_or_404(Lease, pk=lease_id)
    leaseterm = LeaseTerm.objects.filter(lease=lease, is_terminated =False, is_active = True )
    payment = leaseterm.leasepayment_set.all().order_by('payment_date')

但收到错误

'QuerySet'对象没有属性'leasepayment_set'

我做错了什么？

Answer 1

模型LeaseTerm的实例具有属性leasepayment_set，而不是模型LeaseTerm的查询集。您可以通过获取此类实例来访问leasepayment_set。

get代替filter

leaseterm = LeaseTerm.objects.get(lease=lease, ...)
payment = leaseterm.leasepayment_set.all()

循环查询集

leaseterm = LeaseTerm.objects.filter(lease=lease, ...)
for lt in leaseterm: # lt is an instance of LeaseTerm
    payment = lt.leasepayment_set.all()

（通过评论更新，感谢Alasdair和Ingomar）从相关模型开始，它更高效，更优雅的查询表达。
```
LeasePayment.objects.filter(leaseterm__lease=lease)
```

为什么我收到错误：'QuerySet'对象没有属性？

1 个答案: