months_between(date1,date2) 老師說返回日期想減，怎么寫
SQL> select '31-1月-19'-'23-6月-17' from dual;
select '31-1月-19'-'23-6月-17' from dual
ORA-01722: 無效數字
SQL> select months_between('31-5月-18'-'21-6月-17') from dual;
select months_between('31-5月-18'-'21-6月-17') from dual
ORA-00909: 參數個數無效
2020-12-04
select months_between(to_date('20200101','YYYY-MM-DD'),sysdate) from dual;
2018-12-13
直接減不用函數