Django registration checking uniqueness of email in form?

Question

Django

How to check for unique email in the form when registering a user? How to write such a validator?

Answer 1

def clean_email(self):
    email = self.cleaned_data['email'].strip()
    if User.objects.filter(email__iexact=email).exists():
        raise ValidationError('...')
    return email

In general, at the database level, you also need to make a case insensitive unique index like this (postgres):

CREATE UNIQUE INDEX accounts_email_uniq ON accounts_user USING BTREE ((lower((email)::text)));