string connstring = "User ID=XXXXXX;Password=\"XXXXXX\";Data Source=(DESCRIPTION = (ADDRESS_LIST= (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.100.62)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = XXXXXX)))";
            using (OracleConnection conn = new OracleConnection(connstring))
            {
                conn.Open();
                string sql = "select * from MEMBER_USER where rownum<=5 ";
                using (OracleCommand comm = new OracleCommand(sql, conn))
                {
                    using (OracleDataReader rdr = comm.ExecuteReader())
                    {
                        while (rdr.Read())
                        {
                            Console.WriteLine(rdr[0]);
                        }
                    }
                }
            }