How to distinguish field that requires null=True when blank=True is set in Django models?
null=True is used to tell that in DB value can be NULL
blank=True is only for django , so django doesn't raise error if field is blank e.g. in admin interface
so blank=True has nothing to do with DB
NULL requirement will vary from DB to DB, and it is upto you to decide if you want some column NULL or not
Some model fields such as DateTimeField require null=True option when blank=True option is set.
I'd like to know which fields require that (maybe dependent on backend DBMS), and there is any way to do this automatically.