When I use Assert Choice (ChoiceValidator). If value is null and not in choices value, I have a SQL crash.

[1/3] PDOException: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'type' cannot be null

I need to add NotBlankValidator. So it's work.

But, null is not in my authorized choices... So I think I no need to add an other validator.

What do you think about this ? I can make a PR.