The Parameter class
works with the Command class to execute
parameterized commands or call stored procedures. Every
Command object exposes a
Parameters
collection. In this collection,
there is one Parameter object for every input and
output parameter, and an additional Parameter
object to represent a return value, if required.
The Parameter object can also define a mapping
between parameters and columns in a DataSet. This
allows a column value to be submitted (copied from the
DataSet into an input parameter) and refreshed
(copied from an output parameter or return value into the
DataSet) automatically when using the
Update( ) method of the
DataAdapter.