使用 Django 2.0 提交注册后的完整性错误

Question

注册后，我不断收到完整性错误(外键约束失败(。

from django.db import models
from .user import User
from django.core.validators import RegexValidator
from django.db.models.signals import post_save
from django.dispatch import receiver

class Student(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, primary_key=True)
    avatar = models.ImageField(upload_to='media/pictures/', blank=True)
    regex = RegexValidator(r'^d{2}/d{4}',
                           message='Required. 7 characters or fewer. This value must contain only numeric and slash.')
    matric_no = models.CharField(validators=[regex], blank=False, max_length=7, unique=True)
    phone_regex = RegexValidator(regex=r'^+?1?d{9,15}$',
                                 message="Phone number must be entered in the format: '[phone]'. Up to 15 digits allowed.")
    phone_number = models.CharField(validators=[phone_regex], max_length=17, blank=True)  # validators should be a list
    address = models.CharField(max_length=150, blank=True)
    birth_date = models.DateField(null=True, blank=True)
    GENDER_CHOICES = (
            ('M', 'Male'),
            ('F', 'Female'),
        )
    gender = models.CharField(max_length=1, choices=GENDER_CHOICES, null=False, default='M',)

forms.py

class StudentProfileForm(forms.ModelForm):
    avatar = forms.ImageField()
    class Meta:
        model = Student
        fields = ('avatar', 'phone_number', 'address', 'gender', 'matric_no')

views.py

class StudentRegistrationView(CreateView):
    model = Student
    form_class = StudentProfileForm
    template_name = 'registration.html'
    def student_registration(request):
        if request.method == "POST":
            form = StudentProfileForm(request.POST, request.FILES)
            if form.is_valid():
                register = form.save(False)
                register.save()
                return redirect('home')
        else:
            form = StudentProfileForm()
        return render(request, 'accounts/registration.html', {'form': form})

我认为问题可能是matric_no领域，或者你怎么看？

Answer 1

user是一个OneToOneField，不可为空，并且它不是形式，所以你需要分配它。方便的是，您已经在执行解决方案的步骤 1 和 3(使用 commit False 保存表单，然后保存实例(，因此您只需添加缺少的步骤：

if form.is_valid():
    register = form.save(commit=False)
    register.user = request.user
    register.save()

Answer 2

我在模型中使用信号解决问题，并以这种方式编写视图

view.py

def signup(request):
    if request.method == 'POST':
        form = StudentSignUpForm(request.POST)
        if form.is_valid():
            user_obj = form.save(commit=False)
            user_obj.set_password(form.cleaned_data.get('password1'))
            user_obj.save()
            user_login = auth.authenticate(username=user_obj.username, password=form.cleaned_data.get('password1'))
            login(request, user_login)
            return redirect('student_register')
    else:
        form = StudentSignUpForm()
    return render(request, 'registration/signup_form.html', {'form': form})

model.py

@receiver(post_save, sender=User)
    def update_user_profile(sender, instance, created, **kwargs):
        if created:
            Student.objects.create(user=instance)