为什么我得到错误：'QuerySet'对象没有属性？

Question

我有3种型号

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() 

（清洁方法只允许一个LeaseTerm被激活，而不是终止。）

在我看来，我想看看这个租赁公司积极LeaseTerm所做的所有款项

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') 

，但得到一个错误

'QuerySet' object has no attribute '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。您可以通过获取像这样的实例来访问leasepayment_set。

1. get，而不是filter

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

2. 周围的查询集循环

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

3. （通过评论更新，感谢麦金太尔和Ingomar）开始与相关的模型，它是更高效和优雅的查询表达式。

   LeasePayment.objects.filter(leaseterm__lease=lease)