The
DeleteCommand
,
InsertCommand
,
and UpdateCommand objects submit the changes made
to a DataSet back to a data source. This is
however a one-way process; the updated data isn’t
automatically returned back to the DataSet. Often
this is acceptable because after the update, the data in the data
source implicitly matches the data in the DataSet.
This isn’t, however, the case for some data such as
AutoIncrement columns when rows are inserted into
the data source and timestamp columns, which are
updated with a new value whenever the row is updated in the data
source. In both cases, a new value must be retrieved from the data
source row when it’s inserted, or in the case of the
timestamp column, updated or inserted.
The UpdatedRowSource property of each
Command object that submits updates to the data
source determines how data is returned back to the
DataSet. By default, this property is set to
Both, resulting in both the data in the first
returned row and the return values for stored procedures updating the
DataSet after the update. The property can be set
so that only the first returned record or only the return parameters
update the DataSet, or so that the
DataSet isn’t updated.