oracle日期时间判断函数

CREATE OR REPLACE FUNCTION IS_DATETIME( IN_DATE IN VARCHAR2) RETURN INTEGER AS FLAG INTEGER; DATETIME VARCHAR2(8); HOU VARCHAR2(2); MINU VARCHAR2(2); SEC VARCHAR2(2); BEGIN IF IN_DATE IS NULL THEN RETURN 0; ELSE IF LENGTH(IN_DATE)=14 THEN DATETIME :=SUBSTR(IN_DATE,1,8); HOU :=SUBSTR(IN_DATE,9,2); MINU :=SUBSTR(IN_DATE,11,2); SEC :=SUBSTR(IN_DATE,13,2); ELSE RETURN 0; END IF; END IF; FLAG :=IS_DATE(DATETIME); IF FLAG!=0 THEN return FLAG; END IF; IF HOU NOT IN ('01','02','03','04','05','06','07','08','09','10','11','12','13','14','15','16','17','18','19','20','21','22','23') THEN RETURN -2; END IF; IF MINU NOT IN ('01','02','03','04','05','06','07','08','09','10','11','12','13','14','15','16','17','18','19','20','21','22','23','24','25','26', '27','28','29','30','31','32','33','34','35','36','37','38','39','40','41','42','43','44','45','46','47','48','49','50','51','52','53','54','55','56','57' ,'58','59','00') THEN RETURN -3; END IF; IF SEC NOT IN ('01','02','03','04','05','06','07','08','09','10','11','12','13','14','15','16','17','18','19','20','21','22','23','24','25','26', '27','28','29','30','31','32','33','34','35','36','37','38','39','40','41','42','43','44','45','46','47','48','49','50','51','52','53','54','55','56','57' ,'58','59','00') THEN RETURN -4; END IF; RETURN 1; END IS_DATETIME;