ControlContext :: defaultOrder - Get default order key name
The default order is the order defined by the data source of the control. The default order may be changed by calling changeDefaultOrder() . When the data source for the control is unordered or does not support an order key, the function returns an empty string.
Return value: Key name ( odaba::String & )
The key name is the name of a valid collection index (order) or key defined for the data type in the database model.