Explain how ColdFusion handles null values within query result sets.

ColdFusion represents null values retrieved from database query result sets as the special value `cf_null`. This is distinct from other programming languages where null might be represented as `NULL`, `None`, or similar. `cf_null` is a ColdFusion-specific object that signifies the absence of a value in a database field. When a query returns a null value from a database column, ColdFusion automatically converts that database null into a `cf_null` object within the resulting structure (typically an array or a struct). This conversion happens transparently; you don't need to explicitly request it. ColdFusion provides several ways to check for and handle `cf_null` values. The most common is using the `is cf_null` test. Thi....