query e function

[marco pilolli]

ho la seguente query che funziona:

SELECT Conto
FROM gldplancodedetail
JOIN glsdettagliomenufield AS XX ON XX.RecId=gldplancodedetail.TipoConto
WHERE cast(gldplancodedetail.Conto as unsigned) > cast('3000' as unsigned) AND XX.vocemenu='Di Riepilogo'
AND refglsbalanceplangestion=(SELECT refglsbalanceplangestion FROM gldcategorysectorplanaccount WHERE taglevel='1.1.5') AND NOT (gldplancodedetail.visibility=1)
order by cast(Conto as unsigned)
limit 0,1

e funziona e mi ritorna il conto di riepilogo successivo
ma se questo lo metto in una funzione per richiamarlo
mi da altri risultati
ecco la funzione che ho scritto

DELIMITER $$

DROP FUNCTION IF EXISTS `xxxx`.`filtrosaldiconti`$$

CREATE DEFINER=`root`@`%` FUNCTION `filtrosaldiconti`(visconto varchar(10), parid varchar(30)) RETURNS varchar(10) CHARSET latin1
BEGIN
SET @tornocosa = ' ';
SELECT Conto INTO @tornocosa
FROM gldplancodedetail
LEFT JOIN glsdettagliomenufield AS XX ON XX.RecId=gldplancodedetail.TipoConto
WHERE cast(gldplancodedetail.Conto as unsigned) > cast(visconto as unsigned) AND XX.vocemenu='Di Riepilogo'
AND refglsbalanceplangestion=(SELECT refglsbalanceplangestion FROM gldcategorysectorplanaccount WHERE taglevel=parid) AND NOT (gldplancodedetail.visibility=1)
ORDER BY Conto
LIMIT 1 ;
RETURN @tornocosa;
END$$

DELIMITER ;