django - 如何仅更新 django 模型中的特定字段？

Question

我只想更新模型中的特定字段。
这是我的models.py

class Teacher(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    image = models.ImageField(upload_to='teacher/images')
    phone = models.CharField(max_length=15)
    address = models.CharField(max_length=25)
    salary = models.DecimalField(max_digits=20, decimal_places=2)
    joindate = models.DateField(auto_now_add=True)
    status = models.BooleanField(default=True)

这是我的 forms.py

class TeacherForm(forms.ModelForm):
    class Meta:
        model = User
        fields = ['first_name', 'last_name', 'username', 'email', 'password']


class TeacherExtraForm(forms.ModelForm):
    class Meta:
        model = models.Teacher
        fields = ['phone', 'address', 'salary', 'status', 'image']

这是我的 views.py

def update_teacher(request, pk):
    teacher = models.Teacher.objects.get(id=pk)
    user = models.User.objects.get(id=teacher.user_id)
    form1 = forms.TeacherForm(instance=user)
    form2 = forms.TeacherExtraForm(instance=teacher)
    context = {
        'teacher': teacher,
        'user': user,
        'form1': form1,
        'form2': form2
    }
    if request.method == 'POST':
        form1 = forms.TeacherForm(request.POST, instance=user)
        form2 = forms.TeacherExtraForm(request.POST, instance=teacher)
        if form1.is_valid() and form2.is_valid():
            user = form1.save(commit=False)
       
            user.save(update_fields=['first_name', 'last_name', 'email', 'username'])
            f2 = form2.save(commit=False)
            f2.status = True
            f2.save(update_fields=['phone', 'address', 'salary', 'status'])
            return redirect('Teacher:teacher_index')
    return render(request, 'Teacher/update_teacher.html', context)

这里我只想更新first_name、last_name、email、用户名、电话、地址、薪水和状态，而不影响密码和图像字段。当我也添加密码和图像字段时，它可以工作，但我不想在这里更新密码和图像。

Answer 1

通常在这种情况下，一种制作两种形式，一种用于创建，一种用于更新。例如，Django 本身有一个 UserCreateForm [Django-doc]和一个 UserChangeForm [Django-doc] .因此，我们可以构造两种额外的形式:

class TeacherUpdateForm(forms.ModelForm):
    class Meta:
        model = User
        fields = ['first_name', 'last_name', 'username', 'email']

class TeacherUpdateExtraForm(forms.ModelForm):
    class Meta:
        model = models.Teacher
        fields = ['phone', 'address', 'salary', 'status']

在 View 中，我们因此使用这些形式:

from django.shortcuts import get_object_or_404

def update_teacher(request, pk):
    teacher = get_object_or_404(models.Teacher, pk=pk)
    user = teacher.user
    if request.method == 'POST':
        form1 = forms.TeacherUpdateForm(request.POST, instance=user)
        form2 = forms.TeacherUpdateExtraForm(request.POST, instance=teacher)
        if form1.is_valid() and form2.is_valid():
            form1.save()
            from2.instance.status = True
            form2.save()
            return redirect('Teacher:teacher_index')
    else:
        form1 = forms.TeacherUpdateForm(instance=user)
        form2 = forms.TeacherUpdateExtraForm(instance=teacher)
    context = {
        'teacher': teacher,
        'user': user,
        'form1': form1,
        'form2': form2
    }
    return render(request, 'Teacher/update_teacher.html', context)