MySQL 自定义函数

自定义函数

PS：失败！

DELIMITER $$
DROP FUNCTION IF EXISTS `QY_Nanjing_qoe1_repair`.`stand`$$ CREATE FUNCTION `QY_Nanjing_qoe1_repair`.`stand`(a FLOAT)RETURNS FLOAT BEGIN DECLARE x FLOAT DEFAULT 0.0;
SET x=(a-MIN(a))/(MAX(a)-MIN(a));
RETURN x;
END $$ DELIMITER;
#SELECT MAX(B.M)-MIN(B.M) #FROM #( SELECT Q.service_user SU, AVG(Q.SEVERITY) S, AVG(Q.ALARM_NUM) A, AVG(Q.LOSSRATE) L, MAX(Q.MEDIARATE) max, min(Q.MEDIARATE) Min, AVG(Q.VSTQ) V, AVG(Q.MOS_VALUE) MOS from QY_Nanjing_qoe1_repair Q GROUP BY Q.SERVICE_USER #where Q.VSTQ=0.41015625 #)B #WHERE