"You are encouraged not to implement all the business logic in the web application (i.e. your script), instead do it in the database schema using views, triggers or rules. If the system evolves, new ports will be intended to open to the database, and you have to re-implement the logic in each separate database client."
This doesn't make sense to me. I might be misreading it, but I can't see how this adds to security. It sounds like implementing business logic in the database just increases the amount of work you have to do if you ever want to upgrade or change your SQL database.