错误：42601：列定义列表仅允许返回的函数＆＃34;记录＆＃34;

Question

我在postgres中有一个函数返回两个参数，我在我的应用程序中使用C＃来获取out参数的值。但是当我尝试执行代码时，这个错误显示。我不明白我做了什么我正在附上c＃代码和postgres函数。谢谢。 这是postgres函数：

CREATE OR REPLACE FUNCTION sylvia2.pro_att_login_simple_create(
    p_userid text,
    p_originalsn text,
    p_sendersn text,
    p_remark text,
    p_accessmethod text,
    p_photopath text,
    OUT p_outputmessage text,
    OUT p_logindatetime timestamp with time zone)

    LANGUAGE 'plpgsql'

    COST 100
    VOLATILE 
AS $BODY$

 declare
   p_count                numeric;
   p_log_in_out           text;
begin
set search_path to sylvia2;
     select count(userid) into p_count from attendance where userid = p_userid
     and (to_date (to_char (timestamp_server, 'mm/dd/yyyy hh:mi:ss am'), 'mm/dd/yyyy hh:mi:ss am' ))::date = current_date; 

    if(p_count = 0) then select 'in' into  p_log_in_out ;
    else select 'out' into  p_log_in_out  ;
    end if;

    insert into attendance (userid, timestamp, timestamp_server, timestamp_actatek, eventtrigger,  originalsn,
                                   sendersn, remark, accessmethod, photopath
                         )
                 values  (p_userid, current_date,  current_date,  current_date,  p_log_in_out, p_originalsn, 
                             p_sendersn,  p_remark,  p_accessmethod,  p_photopath
                         );

     p_outputmessage :=  p_log_in_out;
     select current_date into p_logindatetime;
end; 

$BODY$;

ALTER FUNCTION sylvia2.pro_att_login_simple_create(text, text, text, text, text, text)
    OWNER TO postgres;

这是C＃代码：

NpgsqlCommand cmd = new NpgsqlCommand();
            cmd.CommandText = "sylvia2.PRO_ATT_LOGIN_SIMPLE_CREATE";
            cmd.CommandType = CommandType.StoredProcedure;

            foreach (empAttendanceDS.EmpAttendance_NoCalculationRow row in attDS.EmpAttendance_NoCalculation.Rows)
            {
                if (clientName == "Uddipan")
                {
                    #region For Uddipan
                    cmd.Parameters.Add("p_UserID", row.LoginID);
                    cmd.Parameters.Add("p_OriginalSN", message);
                    cmd.Parameters.Add("p_SenderSN", message);

                    if (!row.IsRemarkNull()) cmd.Parameters.Add("p_Remark", row.Remark);
                    else cmd.Parameters.Add("p_Remark", remarks);

                    cmd.Parameters.Add("p_AccessMethod", message);
                    cmd.Parameters.Add("p_PhotoPath", message);
                    cmd.Parameters.Add("p_OutputMessage", NpgsqlTypes.NpgsqlDbType.Varchar, 1000).Direction = ParameterDirection.Output;
                    cmd.Parameters.Add("p_LoginDateTime", NpgsqlTypes.NpgsqlDbType.Date, 1000).Direction = ParameterDirection.Output;
                    bError = false;
                    nRowAffected = -1;
                    nRowAffected = ADOController.Instance.ExecuteNonQuery(cmd, connDS.DBConnections[0].ConnectionID, ref bError);
                    if (bError == true)
                    {
                        ErrorDS.Error err = errDS.Errors.NewError();
                        err.ErrorCode = ErrorCode.ERR_DB_OPERATION_FAILED.ToString();
                        err.ErrorTier = ErrorTier.ERR_TIER_DL.ToString();
                        err.ErrorLevel = ErrorLevel.ERR_LEVEL_SEVER.ToString();
                        err.ErrorInfo1 = ActionID.ACTION_ADD_ATTENDANCE_SIMPLE_LOGIN.ToString();
                        errDS.Errors.AddError(err);
                        errDS.AcceptChanges();
                    }
                    successMsg = cmd.Parameters["p_OutputMessage"].Value.ToString();
                    loginDateTime = cmd.Parameters["p_LoginDateTime"].Value.ToString();
                    stringDS.DataStrings.AddDataString(successMsg);
                    stringDS.DataStrings.AddDataString(loginDateTime);
                    stringDS.AcceptChanges();