AdsCommand.DeriveParameters

Populates the AdsCommand.Parameters collection with the parameter information for the stored procedure specified in AdsCommand.CommandText.

public void DeriveParameters();

Remarks

DeriveParameters provides a simple method for populating the Parameters collection prior to executing a stored procedure. If AdsCommand.CommandType is not set to StoredProcedure, this method throws an ArgumentException.

The DeriveParameters method creates one AdsParameter object for each parameter defined for the stored procedure in the Advantage Data Dictionary. It fills in the AdsParameter.ParameterName, AdsParameter.DbType, and AdsParameter.Direction properties. Note that if you are using a stored procedure to perform the updates with an AdsDataAdapter, you will probably need to set the AdsParameter.SourceColumn property to match the DataSet column names after calling DeriveParameters.

This call requires a round trip to the server to retrieve the parameter information for the named stored procedure. Therefore, it is more efficient to set the parameter information explicitly.

Example

conn = new AdsConnection( "data source=c:\\data\\test.add;" +

"user id=test;" );

conn.Open();

AdsCommand cmd = conn.CreateCommand();

// assign the procedure name

cmd.CommandText = "testproc";

// set command type to stored procedure

cmd.CommandType = CommandType.StoredProcedure;

// load the parameter collection from the data dictionary info

cmd.DeriveParameters();

// assign in put parameters

cmd.Parameters["inparam1"].Value = 234;

cmd.Parameters["inparam2"].Value = "xyz";

// execute the stored procedure

cmd.ExecuteNonQuery();

// print an output parameter

Console.WriteLine( cmd.Parameters["outparam"].Value );