Django:如何修复 RelatedOjbectDoesNotExist 异常？

Question

型号:

class Users(models.Model):
    first_nm = models.CharField('First Name', max_length=100)
    last_nm = models.CharField('Last Name', max_length=100)
    email = models.EmailField('Email Address', max_length=200, unique=True )

class Invoices(models.Model):
    invoice_date = models.DateField('created date', auto_now=True)
    user = models.ForeignKey(Users)

查看:

    def post(self, request):
    bound_form = UsersForm(request.POST)

    if bound_form.is_valid() and lineItemsForm.is_valid() and formset.is_valid():
        u = Users()
        u.first_nm = bound_form.cleaned_data['first_nm']
        u.last_nm = bound_form.cleaned_data['last_nm']
        u.email = bound_form.cleaned_data['email']
        u.save()
        i = Invoices()
        i.user.add(u)
        i.save()

在我调用 i.save() 之后，我得到了这个:

Request Method: POST
Request URL:    http://gpga-hrguys.rhcloud.com/players/create_user/
Django Version: 1.8.4
Exception Type: RelatedObjectDoesNotExist
Exception Value:    
Invoices has no user.

Invoices怎么可能没有用户呢？我在调用 i.save() 之前将它添加到 Invoices 对象

Answer 1

您在发票中设置的用户有误。因为它是一个ForeignKey，所以简单地说:

i.user = u
i.save()

i.user.add(u) 如果用户是 ManyToMany 字段。 为了您的信息，您可以通过调用访问用户的所有发票:

u.invoice_set