Issue: Some fields should not be NULL in openedx/ecommerce

[byshen]

Hi @bjh

Thank you for your reply. I actually find similar issues in the edx-platform repo too. I just posted here. Could you take a look? I can create PRs for this if needed. Thanks!

Issue: Some fields should have unique constraint in openedx/edx-platform

1. Constraint in class CertificateInvalidation generated_certificate should be unique in the model CertificateInvalidation, as one certificate should not be invalidated twice. This would cause exceptions in the program which hurts the data integrity. We can add unique=True to prevent that. In file lms/djangoapps/certificates/models.py class CertificateInvalidation(TimeStampedModel): """ Model for storing Certificate Invalidation. .. no_pii: """ generated_certificate = mode…