DELIMITER $$
CREATE FUNCTION CalculaDuracaoMediaEstadias()
RETURNS FLOAT
DETERMINISTIC
BEGIN
DECLARE MediaDuracao FLOAT;
SELECT ROUND(AVG(DATEDIFF(data_fim,data_inicio))) INTO MediaDuracao FROM alugueis;
RETURN MediaDuracao;
END$$
DELIMITER ;
SELECT CalculaDuracaoMediaEstadias();
