Points to the list of field definitions for the dataset.
Syntax:
property FieldDefs: TFieldDefs;
Description:
FieldDefs lists the field definitions for a dataset. While an application can examine
FieldDefs to explore the field definitions for a dataset, it should not change these definitions
unless creating a new table with CreateTable or CreateDataSet.
To access fields and field values in a dataset, use the Fields, AggFields, and
FieldValues properties, and the FieldsByName method.
 | If the dataset includes object field descendants, FieldDefs represents a hierarchical view
of the data, meaning that the definitions include object field definitions. To determine the definitions
in a flattened view, use FieldDefList instead. |