DELIMITER $$
$$
CREATE OR REPLACE DEFINER=`root`@`localhost` FUNCTION `vn`.`hasAnyNegativeBase`() RETURNS tinyint(1)
    DETERMINISTIC
BEGIN

/**
*	Calcula si existe alguna base imponible negativa
*	Requiere la tabla temporal tmp.ticketToInvoice(id) para getTaxBases()
*
*	returns BOOLEAN
*/

	DECLARE hasAnyNegativeBase BOOLEAN;

    CALL getTaxBases();

	SELECT negative INTO hasAnyNegativeBase
        FROM tmp.taxBases
        LIMIT 1;

	DROP TEMPORARY TABLE
        tmp.ticketTax,
        tmp.ticket,
        tmp.taxBases;

	RETURN hasAnyNegativeBase;

END$$
DELIMITER ;