Unique and null

I have just made a CharField unique and Django detects duplicates nicely
but seems to ignore multiple instances where the field value is null.

    arn = models.CharField(
        max_length=MEDIUM,
        unique=True,
        null=True,
        blank=True,
    )

Is this correct behaviour?

Thanks

Mike



--
Signed email is an absolute defence against phishing. This email has
been signed with my private key. If you import my public key you can
automatically decrypt my signature and be sure it came from me. Just
ask and I'll send it to you. Your email software can handle signing.

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/fb02525d-773c-4ce3-43a2-f41397176a36%40dewhirst.com.au.