title: Calling AS400 Programs through OleDb causes InvalidCastException
body: <p>I am trying to call an RPG program on our AS/400 machine using OleDb. As soon as there are more complex types such as dates and decimals I seem to be getting the following error:</p>
  
  <blockquote>
    <p>The data value could not be converted for reasons other than sign mismatch or data overflow. For example, the data was corrupted in the data store but the row was still retrievable.</p>
  </blockquote>
  
  <p>Here is the code that produces the problem:</p>
  
  <pre><code>            //            'p_refno                     9a     ()
          //'p_projdat                   *date (output parm)
          //'p_amount                    13p, 2 (output parm)
          //'p_rtnsts                    1a (output parm)
          using (OleDbConnection cn = new OleDbConnection("Provider=IBMDA400;Data Source=MyAs400;User ID=MyUser;Password=MyPassword;"))
          {
              cn.Open();
              OleDbCommand cmd = new OleDbCommand("{{call PGMLIB.MYPROGRAM(?,?,?,?,?,?,?)}}", cn);
              cmd.CommandType = System.Data.CommandType.Text;
  
              OleDbParameter p_refno = new OleDbParameter("p_refno","ED4565654");
              OleDbParameter p_projdat = new OleDbParameter("p_projdat", new DateTime());
              p_projdat.Direction = System.Data.ParameterDirection.Output;
              p_projdat.Size = 8;
              OleDbParameter p_amount = new OleDbParameter("p_amount", new Decimal());
              p_amount.Direction = System.Data.ParameterDirection.Output;
              OleDbParameter p_rtnsts = new OleDbParameter("p_rtnsts", " ");
              p_rtnsts.Direction = System.Data.ParameterDirection.Output;
              p_rtnsts.Size = 1;
              p_amount.DbType = System.Data.DbType.Decimal;
              cmd.Parameters.Add(p_refno);
              cmd.Parameters.Add(p_mode);
              cmd.Parameters.Add(p_source);
              cmd.Parameters.Add(p_type);
              cmd.Parameters.Add(p_projdat);
              cmd.Parameters.Add(p_amount);
              cmd.Parameters.Add(p_rtnsts);
              cmd.ExecuteNonQuery();
              Console.WriteLine(p_projdat.Value.ToString());
              Console.WriteLine(p_amount.Value.ToString());
              Console.WriteLine(p_rtnsts.Value.ToString());
  
          }
          Console.WriteLine("Press any key to quit...");
          Console.ReadKey();
  </code></pre>
  
  <p>What am I doing wrong? </p>