How can I save a model that should be unique but also allowed to be null in Django. For instance I have the following model...
class PetOwner(models.Model):
"""Model representing a pet owner."""
user = models.OneToOneField(User, on_delete=models.CASCADE)
first_name = models.CharField(max_length=50, help_text="Enter owner's first name")
last_name = models.CharField(max_length=50, help_text="Enter owner's last name")
email = models.EmailField(
max_length=50, blank=True, unique=True, help_text="Enter owner's email"
)
phone_number = models.CharField(
max_length=15, blank=True, unique=True, help_text="Enter owner's phone number"
)
address = models.ForeignKey(
"Address", on_delete=models.SET_NULL, null=True, blank=True
)
I want my app to work the following way. A PetOwner can sign up but when they do they initially only sign up with a username, password, a confirmation password, and first_name, and last_name. I want my to have a profile page which will allow for updating the PetOwner to include their phone_number but I do not necessarily want to make this a requirement. I decided that I'd make phone_number field null=True and blank=True but as soon as I register a second user I get a django.db.utils.IntegrityError: UNIQUE constraint failed: app_petowner.phone_number error. I believe it is because when I register a user for some reason instead of phone_number being None even when I did not actually add a phone number at all it shows up as an empty string. Not sure why this is happening and I am not sure how to fix it.
