Error in executing Oracle Stored Procedure using C#

These modifications in your code worked for me:

using (connection){    Int32 id = 1;    OracleCommand cmd = new OracleCommand("TESTP", connection);    cmd.CommandType = CommandType.StoredProcedure;    cmd.Parameters.Add("tempID", OracleDbType.Int32, ParameterDirection.Input).Value = id;    cmd.Parameters.Add("tempName", OracleDbType.Varchar2, 200).Direction = ParameterDirection.Output;    cmd.Parameters.Add("tempLName", OracleDbType.Varchar2, 200).Direction = ParameterDirection.Output;    cmd.ExecuteNonQuery();    string FName = cmd.Parameters["tempName"].Value.ToString();    string LName = cmd.Parameters["tempLName"].Value.ToString();}

You could also add exception blocks in Oracle procedure to handle no_data_found exception and avoid ORA-01403 error, like here:

CREATE OR REPLACE PROCEDURE TESTP (tempID  IN  TESTTABLE.ID%Type,    tempName out TESTTABLE.NAME%TYPE, tempLName out TESTTABLE.LNAME%TYPE) ASBEGIN  select Name, LNAME Into tempName,tempLName from TestTable Where ID = tempID;EXCEPTION WHEN NO_DATA_FOUND THEN  tempName := null;  tempLName := null;END;

and add additional OUT parameter informing about success or failure and handle it in C# code.