Django：NOT NULL 约束失败：wishlist_wish.user_id

Question

I have a wishlist app with a custom user model. I added the user as the foreign key to each wishlist item. However, I am only able to add the foreign key by specifying a default user, even after deleting the existing db files and running makemigrations and migrate. The default user is associated with the wishlist item regardless of which user is logged in, and if I don't include a default user I get the "NOT NULL constraint failed: wishlist_wish.user_id" error.

How can I update the code so that the wishlist item is associated with the logged-in user creating the item?

A related question is whether I need to include a user id in my custom user model? I tried doing this as well and ran into the same problem. Thanks in advance.

Wish Model:

class Wish(models.Model):
    name = models.TextField()
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, default=1)

    def __str__(self):
        return self.name

Wish View:

def add_wish(request):

    user = request.user
    wishes = Wish.objects.filter(user=request.user)

    if request.method == 'POST':
        form = WishForm(request.POST)

        if form.is_valid():
            form.save()
            return redirect('home')
    else:
        form = WishForm()

    context = {'form' : form, 'wishes' : wishes}
    return render(request, 'wishlist/add_wish.html', context)

Wish Form:

class WishForm(ModelForm):
    class Meta:
        model = Wish
        fields = ('name', )

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['name'].widget.attrs.update({'class' : 'textarea', 'placeholder' : 'Enter wishlist item'})

Custom User (Account) Model:

class MyAccountManager(BaseUserManager):
    def create_user(self, email, username, first_name, last_name, password=None):
        if not email:
            raise ValueError("Users must provide an email to create an account.")
        if not first_name:
            raise ValueError("Users must provide full name to create an account.")
        if not last_name:
            raise ValueError("Users must provide full name to create an account.")

        user =  self.model(
                email = self.normalize_email(email),
                username = username,
                first_name = first_name,
                last_name = last_name,
            )

        user.set_password(password)
        user.save(using=self._db)
        return user
    
    def create_superuser(self, email, username, first_name, last_name, password):
        user =  self.create_user(
                email = self.normalize_email(email),
                username = username,
                first_name = first_name,
                last_name = last_name,
                password = password
            )
        user.is_admin = True
        user.is_staff = True
        user.is_superuser = True
        user.save(using=self._db)
        return user


class Account(AbstractBaseUser):
    email = models.EmailField(max_length=100, unique=True)
    username = models.CharField(max_length=100, unique=False, blank=True, null=True)
    date_joined = models.DateTimeField(auto_now_add=True)
    last_login = models.DateTimeField(auto_now=True)
    is_admin = models.BooleanField(default=False)
    is_active = models.BooleanField(default=True)
    is_staff = models.BooleanField(default=False)
    is_superuser = models.BooleanField(default=False)
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['username', 'first_name', 'last_name']

    objects = MyAccountManager()

    def __str__(self):
        return self.first_name + " " + self.last_name

    def has_perm(self, perm, obj=None):
        return self.is_admin

    def has_module_perms(self, app_label):
        return True

Answer 1

You simply need to provide a value for the .user for the Wish you are creating:

from django.contrib.auth.decorators import login_required

@login_required
def add_wish(request):
    wishes = Wish.objects.filter(user=request.user)

    if request.method == 'POST':
        form = WishForm(request.POST)

        if form.is_valid():
            form
            form.save()
            return redirect('home')
    else:
        form = WishForm()

    context = {'form' : form, 'wishes' : wishes}
    return render(request, 'wishlist/add_wish.html', context)

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Note : You can limit views to a view to authenticated users with the @login_required decorator [Django-doc] .