Validation Exclude Self From QuerySet

Question

Originally I had this in my models.py

def validate_project_name(value,self):
    project_name = Team.objects.filter(Project_name=value)
    if self.pk:
        project_name = project_name.exclude(pk=self.pk)
    if project_name:
        raise ValidationError('This already exists.')


class Team(models.Model):
    Project_name = models.CharField(max_length=250, validators=[validate_project_name])
    Project_number = models.IntegerField()

This worked in the sense that it will not allow users to input an already existing Project_name . However, now I have incorporated an edit/update functionality. So if a user wants to update his/her own Team , it will raise the ValidationError since it exists in the database. So for example, if the User wants to keep the same Project_name but update the Project_number the error will raise. So I want to exclude self from the queryset. I looked at this example:

django exclude self from queryset for validation

So I simply added the following code within my class Team .

def clean_name(self):
    project_name = self.cleaned_data['Project_name'].title()
    qs = Team.objects.filter(Project_name=project_name)
    if self.instance.pk is not None:
        qs = qs.exclude(pk=self.instance.pk)
    if qs.exists():
        raise ValidationError("This already exists")

But it is not working as in the validation error is not being raised...Any ideas?

Answer 1

Can you make sure clean_name is even getting called? I was under the impression that models only had a clean method, not a method for each individual field (that syntax is used for forms). Try using just def clean(self):

https://docs.djangoproject.com/en/1.10/ref/models/instances/#django.db.models.Model.clean