DataMapper ORM v1.8.0

[eluser]Mark Price[/eluser]
I am wanting to update a row that already exists in the database and set one of its fields to NULL.

For example, I have two different user types and one of the user types has an extra field in the database to store data that doesn't apply to the other user type.

My goal is to be able to change the user type from an admin panel on an existing user and that would set the inapplicable field to NULL.