判定一个字符串是否为有效时间的函数

CREATE OR REPLACE FUNCTION is_date(parameter VARCHAR2) RETURN NUMBER IS

val DATE ;

BEGIN

val := TO_DATE(NVL(parameter, 'a' ), 'yyyy-mm-dd hh24:mi:ss' );

RETURN 1;

EXCEPTION

WHEN OTHERS THEN

RETURN 0;

END ;

alter session force parallel ddl parallel 8;

create table TT as select t.id,

floor(months_between(sysdate,to_date(t.birthday, 'yyyymmdd' ))/12) age

from TT_WXTRAN t

where is_date(t.birthday)!=0;