What if, for example, parameterized queries were built using subsequent forms, the first chose the query, the second presented parameter options based on that query --where all parameters were then validated?
This sounds more like a UI issue, if the query is fully determined, I guess that the forms page would do validation, and the approved_p flag could be set. In this case, it would just be an application that uses the Cron Package. An admin which loads the package is essentially happy with the amount of validation that is taking place.
