python - /updatestudent/3 处的 Django ValueError 无法分配“'1'”：“Student.class

问题描述

/updatestudent/3 处的 ValueError 无法分配“'1'”：“Student.class_id”必须是“Class”实例。当我尝试更新我的学生模型时会出现此错误。当我更新用户名时，它不会引发任何错误，但如果我不更新用户名，则只会引发此错误

任何帮助都是有帮助的。

模型.py

class CustomUser(AbstractUser):
    user_type_data = ((1,'HOD'),(2,'Staff'),(3,'Student'))
    user_type = models.CharField(default=1, choices=user_type_data, max_length=10)
class Student(models.Model):
    id = models.AutoField(primary_key=True)
    admin = models.OneToOneField(CustomUser, on_delete=models.CASCADE)
    gender = models.CharField(default=1, choices=gender_type, max_length=10)
    profile = models.ImageField(upload_to='student/profile-images/%y/%m/%d/', default='student/profile-images/default.jpg', blank=False, null=False)
    address = models.TextField()
    class_id = models.ForeignKey(Class, on_delete=models.CASCADE, default=1)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now_add=True)
    objects = models.Manager()
    def full_name(self):
        return self.admin.first_name+' '+self.admin.last_name

    def __str__(self):
        return self.admin.username

class Session(models.Model):
    id = models.AutoField(primary_key=True)
    session_start= models.IntegerField()
    session_end = models.IntegerField()
    objects = models.Manager()
    def __str__(self):
        return f'{self.session_start} {self.session_end}'

class Course(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now_add=True)
    objects = models.Manager()
    def __str__(self):
        return self.name

class Class(models.Model):
    id = models.AutoField(primary_key=True)
    course = models.ForeignKey(Course, on_delete=models.CASCADE)
    branch = models.CharField(default='CSE', choices=branch_data, max_length=40)
    year = models.CharField(default='First Year', choices=year_data, max_length=15)
    session = models.ForeignKey(Session, on_delete=models.CASCADE)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now_add=True)
    objects = models.Manager()

    def __str__(self):
        return f'{self.course} {self.branch} {self.year} {self.session}'

    def name(self):
        return f'{self.course} {self.branch} {self.year} {self.session}'

表格.py

from django import forms
from django.contrib.auth.models import User
from django.contrib.auth.forms import UserChangeForm, UserCreationForm
from django.db.models import fields
from .models import (AdminHOD, Staff, Student, Class,  
                    CustomUser, Course, Session, Attendance, 
                    ExamType, Exam, Subject)
from .models import branch_data, year_data


gchoice = (('1','Male'),('2','Female'))
sesschoice = tuple((i.id, i.id) for i in Session.objects.all())
courchoice = tuple((i.id,i) for i in Course.objects.all())
choice_exam = tuple((i.id,i.name) for i in ExamType.objects.all())
all_class = tuple((i.id, i.name) for i in Class.objects.all())

class UserUpdateForm(UserChangeForm):
    email = forms.EmailField()

    class Meta:
        model = User
        fields = ['first_name', 'last_name', 'username', 'email']

class StudentUpdateForm(forms.ModelForm):
    gender = forms.ChoiceField(choices=gchoice)
    address = forms.CharField()
    class_id = forms.ChoiceField(choices=all_class)

    class Meta: 
        model = Student
        fields = ['gender', 'class_id', 'address']

视图.py

    if request.method=='POST':
        uform = UserUpdateForm(request.POST)
        sform = StudentUpdateForm(request.POST)
        if uform.is_valid():
            address = request.POST.get('address')
            username = request.POST.get('username')
            clas = Class.objects.get(id=request.POST['class_id'])
            email = request.POST.get('email')
            gender = request.POST.get('gender')
            print(clas)
            try:
                student = Student.objects.get(id=id)
                user = student.admin
                user.username = username
                user.email = email
                user.save()
                student.address = address
                student.gender = str(gender)
                student.class_id = clas
                student.updated_at = datetime.datetime.now()
                student.save()
                messages.success(request,'Student successfully Updated.')
                return redirect('/managestudent')
            except:
                messages.error(request,'Student has not been Updated due to some technical issues.')
                return render(request, 'cmsapp/hod/studentupdate.html', {'uform':uform,'sform':sform})
        else:
            messages.error(request,sform.errors)
            return render(request, 'cmsapp/hod/studentupdate.html', {'uform':uform,'sform':sform})

    else:
        uform = UserUpdateForm(instance=Student.objects.get(id=id).admin)
        sform = StudentUpdateForm(instance=Student.objects.get(id=Student.objects.get(id=id).id))
        return render(request, 'cmsapp/hod/studentupdate.html', {'uform':uform,'sform':sform})

学生更新.html

        <h3>Update Student</h3>
        <form action="" method="POST" class="form-group">
            {% csrf_token %}
            {{uform}}
            {{sform}}
            <button type="submit">Update Student</button>
        </form>
    </div>

追溯

Traceback (most recent call last):
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\CollegeErp\cmsapp\hodviews.py", line 176, in update_student
    messages.error(request,sform.errors)
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\forms\forms.py", line 172, in errors
    self.full_clean()
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\forms\forms.py", line 376, in full_clean
    self._post_clean()
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\forms\models.py", line 400, in _post_clean
    self.instance = construct_instance(self, self.instance, opts.fields, opts.exclude)
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\forms\models.py", line 63, in construct_instance
    f.save_form_data(instance, cleaned_data[f.name])
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\db\models\fields\__init__.py", line 891, in save_form_data
    setattr(instance, self.name, data)
  File "C:\Users\Akash Deep Saingar\Desktop\MySite\venv\lib\site-packages\django\db\models\fields\related_descriptors.py", line 215, in __set__
    raise ValueError(

Exception Type: ValueError at /updatestudent/3
Exception Value: Cannot assign "'1'": "Student.class_id" must be a "Class" instance.

标签： pythondjangodjango-modelsdjango-viewsdjango-forms

python - /updatestudent/3 处的 Django ValueError 无法分配“'1'”：“Student.class_id”必须是“Class”实例

问题描述

解决方案

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