oracle sysdate的使用

SQL> select sysdate from dual union select sysdate+(1/(24*60*60)) from dual;            //時間加一秒

SYSDATE
-------------------
2010.07.14 15:44:13
2010.07.14 15:44:14

SQL> select sysdate from dual union select sysdate+1 from dual;                        //時間加一天

SYSDATE
-------------------
2010.07.14 15:45:05
2010.07.15 15:45:05

SQL> select sysdate from dual union select sysdate+(1/24) from dual;                   //時間加一小時

SYSDATE
-------------------
2010.07.14 15:46:01
2010.07.14 16:46:01

SQL> select sysdate from dual union select sysdate+(1/(24*60)) from dual;              //時間加一分

SYSDATE
-------------------
2010.07.14 15:46:41
2010.07.14 15:47:41