||Base class for all hydrators. A hydrator is a class that provides some form of
transformation of an SQL result set into another structure.
||The ArrayHydrator produces a nested array "graph" that is often (not always)
interchangeable with the corresponding object graph for read-only access.
||Represents a result structure that can be iterated over, hydrating row-by-row
during the iteration. An IterableResult is obtained by
||The ObjectHydrator constructs an object graph out of an SQL result set.
||Hydrator that produces flat, rectangular results of scalar data. The created
result is almost the same as a regular SQL result set, except that column names
are mapped to field names and data type conversions take place.
||Hydrator that hydrates a single scalar value from the result set.