Used to map fields of unknown data types to TStringField (TWideStringField).
property UnknownAsString: boolean default False;
Use the UnknownAsString to map fields of unknown data types to TStringField (TWideStringField). If False, fields of unknown data types (for example the ifnull function result) are mapped to TMemoField or TWideMemoField depending on the value of the UseUnicode option. Memo is used because maximum length of values from such fields is unknown. If True, fields of unknown data types are mapped to TStringField or TWideStringField depending on the value of the UseUnicode option. Size of fields is set to 8192. Values larger than this size are truncated. The default value is False.