Question

Hi Here’s a snippet from my admin.py

#admin.py
class UserForm(forms.ModelForm):
    class Meta:
        model = User

    def clean_email(self):
        email = self.cleaned_data['email']
        if User.objects.filter(email=email).exists():
            raise forms.ValidationError("This email already used")
        return email

class UserAdmin(admin.ModelAdmin):
    form = UserForm

admin.site.unregister(User)
admin.site.register(User, UserAdmin)

I use this to check that a new user cannot be created with an email address already used. The problem is that when I edit an existing user the validation check fails, because there is a user with that mail address, but that’s OK because it’s the one I’m editing.

How can I tell the form validation to ignore the match against the current user?

Answer 1

Exclude the current instance from your query:

def clean_email(self):
    email = self.cleaned_data['email']
    if User.objects.filter(email=email).exclude(pk=self.instance.pk).exists():
        raise forms.ValidationError("This email already used")
    return email