Oracle 把秒转成时分秒格式(hh24:mm:ss);检测字符串是否是数字;字符串转换为数字

CREATE OR REPLACE FUNCTION to_time(sec IN NUMBER) RETURN VARCHAR2 IS
/*把秒转成时分秒格式
auth lzpong 201/09/16
*/
BEGIN
RETURN TRUNC(NVL(sec,0)/3600)||':'||SUBSTR(NUMTODSINTERVAL(NVL(sec,0), 'second'),15,5);
EXCEPTION WHEN OTHERS THEN RETURN '0:00:00';
END to_time;

CREATE OR REPLACE FUNCTION isnumeric(str IN VARCHAR2) RETURN NUMBER IS
/*检测字符串是否是数字 null:-1; notnumeric:0; isnumeric:1
*/
v_str FLOAT;
BEGIN
IF str IS NULL THEN
RETURN -1;
ELSE
BEGIN
SELECT TO_NUMBER (str) INTO v_str FROM DUAL;
EXCEPTION
WHEN INVALID_NUMBER THEN
RETURN 0;
END;
RETURN 1;
END IF;
END isnumeric;

CREATE OR REPLACE FUNCTION TO_NUM(str IN VARCHAR2) RETURN NUMBER IS
--将字符串转成数字
--lzpong 2015/09/16
BEGIN
IF(str IS NULL)THEN
RETURN 0;
ELSE
RETURN TO_NUMBER(str);
END IF;
EXCEPTION
WHEN OTHERS THEN
RETURN 0;
END;

CREATE OR REPLACE FUNCTION TO_NUM(str IN VARCHAR2) RETURN NUMBER IS
str2 varchar2(160);
--将字符串(提取数字)转成数字
--lzpong 2015/09/16
BEGIN
str2:=REGEXP_SUBSTR(str,'[[:digit:]]{1,100}\.?[[:digit:]]{0,10}');
IF(str2 IS NULL)THEN
RETURN 0;
ELSE
RETURN TO_NUMBER(str2);
END IF;
EXCEPTION
WHEN OTHERS THEN
RETURN 0;
END;