Column mappings define the relationships between columns in the data source and columns in the destination.
By default, it is an empty collection.
The property cannot be modified while a WriteToServer method call is executing.
If the ColumnMappings object is empty when the WriteToServer method is executed, then the first column in the source is mapped
to the first column in the destination, the second is mapped to the second, and so on. This takes place as long as the column
types are convertible, there are at least as many destination columns as source columns, and any extra destination columns