[Fixed]-Django: model can be created without model field data?

The values are left empty. Because null=False, Django doesn’t store empty values as null for these fields, and instead the database uses the empty string ('') for a varchar column that doesn’t get a value.

blank is used for validation, e.g. when validating a ModelForm. It is not related to database constraints. You don’t do any validation here, so it’s not relevant.