一个简单的修改sys用户密码的问题

                //数据库连接字符串

                string oracleStr = string.Format(@"Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST={0})(PORT=1521)))(CONNECT_DATA=(SERVER={0})(SERVICE_NAME={1})));User={2};Password={3};Persist Security Info=true;", ip, sid, uid, oldPwd);



                //打开数据库

                OracleConnection con = new OracleConnection(oracleStr);

                con.Open();//在这里提示： ORA-28009: 应当以 SYSDBA 身份或 SYSOPER 身份建立 SYS 连接



                //执行

                string cmdStr = "update dba_users set password='" + newPwd + "' where username='" + uid + "'";

                OracleCommand cmd = new OracleCommand(cmdStr, con);

                cmd.ExecuteNonQuery();



                //关闭数据库连接

                con.Close();

                con.Dispose();