Help With Parameterized Query Building Dataset

I have a class that works fine using the SQLDataReader but when I try and duplicate the process using a Dataset instead of a SQLDataReader it returnsa a null value.

This is the code for the Method to return a datareader

 

public SqlDataReader GetOrgID()

{

Singleton s1 = Singleton.Instance();

Guid uuid;

uuid = new Guid(s1.User_id);

SqlConnection con = new SqlConnection(conString);

string selectString = "Select OrgID From aspnet_OrgNames Where UserID = @UserID";

SqlCommand cmd = new SqlCommand(selectString, con);

cmd.Parameters.Add("@UserID", SqlDbType.UniqueIdentifier, 16).Value = uuid;

 

con.Open();

SqlDataReader dtr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

 

 

return dtr;

 

This is the code trying to accomplish the same thing with a Dataset instead.

 

public DataSet organID(DataSet dataset)

{

Singleton s1 = Singleton.Instance();

Guid uuid;

uuid = new Guid(s1.User_id);

string queryString = "Select OrgID From aspnet_OrgNames Where UserID = @UserID";

SqlConnection con = new SqlConnection(conString);

 

SqlCommand cmd = new SqlCommand(queryString, con);

cmd.Parameters.Add("@UserID", SqlDbType.UniqueIdentifier, 16).Value = uuid;

 

SqlDataAdapter adapter = new SqlDataAdapter();

adapter.SelectCommand = cmd;

 

adapter.Fill(dataset);

return dataset;

 

 

 

}

 

Assume that the conString is set to a valid connection string. The Singlton passes the userid in from some code in the code behind page ...this functionality works as well.

So assume that the Guid is a valid entry..I should return a valid dataset but its null.