sql - ORA-01843“不是有效月份”和 ORA-01861“文字与格式字符串不匹配”

Question

SQL> select to_timestamp('2010-12-14:09:56:53') - to_timestamp('2010-12-14:09:56:46') from dua
l;
select to_timestamp('2010-12-14:09:56:53') - to_timestamp('2010-12-14:09:56:46') from dual
                    *
ERROR at line 1:
ORA-01843: not a valid month


SQL> select to_date('2010-12-14:09:56:53') - to_date('2010-12-14:09:56:46') from dual;
select to_date('2010-12-14:09:56:53') - to_date('2010-12-14:09:56:46') from dual
               *
ERROR at line 1:
ORA-01861: literal does not match format string

做一个正确的方法是什么

2010-12-14:09:56:53
minus
2010-12-14:09:56:46

在 Oracle SQL 中？

Answer 1

您必须指定时间戳字符串所在的格式TO_DATE和TO_TIMESTAMP功能：

select 
    to_date('2010-12-14:09:56:53', 'YYYY-MM-DD:HH24:MI:SS') - 
    to_date('2010-12-14:09:56:46', 'YYYY-MM-DD:HH24:MI:SS') 
from dual;

结果将以天为单位，您可以乘以 86,400 以获得秒数：

TO_DATE('2010-12-14:09:56:53','YYYY-MM-DD:HH24:MI:SS')-TO_DATE('2010-12-14:09:56
--------------------------------------------------------------------------------
.000081019

---

使用TO_TIMESTAMP：

select 
    to_timestamp('2010-12-14:09:56:53', 'YYYY-MM-DD:HH24:MI:SS') - 
    to_timestamp('2010-12-14:09:56:46', 'YYYY-MM-DD:HH24:MI:SS') 
from dual;

结果将采用以下TIMESTAMP格式：

TO_TIMESTAMP('2010-12-14:09:56:53','YYYY-MM-DD:HH24:MI:SS')-TO_TIMESTAMP('2
---------------------------------------------------------------------------
+000000000 00:00:07.000000000

Answer 2

使用 to_timesatmp

select TO_TIMESTAMP('2010-12-14:09:56:53',  'YYYY-MM-DD:HH24:MI:SS.FF') 
 - TO_TIMESTAMP('2010-12-14:09:56:46',  'YYYY-MM-DD:HH24:MI:SS.FF') 

from dual