An integer specifying the ordinal of the column being mapped to in the destination table or -1 if the property is not set.
The DestinationColumn property and DestinationOrdinal property are mutually exclusive. The most recently set value takes priority.
Setting the DestinationColumn property causes the DestinationOrdinal property to be set to -1. Setting the DestinationOrdinal
property causes the DestinationColumn property to be set to a null reference (Nothing in Visual Basic).