DB2 小技巧

1. 取時間點的年份的寫法:
   SELECT YEAR(current timestamp) FROM SYSIBM.SYSDUMMY1;
2. 取時間點的月份的寫法:
   SELECT MONTH(current timestamp) FROM SYSIBM.SYSDUMMY1;
3. 取時間點的日的寫法:
   SELECT DAY(current timestamp) FROM SYSIBM.SYSDUMMY1;
4. 取時間點的時的寫法:
   SELECT HOUR(current timestamp) FROM SYSIBM.SYSDUMMY1;
5. 取時間點的分的寫法:
   SELECT MINUTE(current timestamp) FROM SYSIBM.SYSDUMMY1;
6. 取時間點的秒的寫法:
   SELECT SECOND(current timestamp) FROM SYSIBM.SYSDUMMY1;
7. 取時間點的毫秒的寫法:
   SELECT MICROSECOND(current timestamp) FROM SYSIBM.SYSDUMMY1;
8. 取時間點的日期的寫法:
   SELECT DATE(current timestamp) FROM SYSIBM.SYSDUMMY1;
9. 取時間點的時間的寫法:
   SELECT TIME(current timestamp) FROM SYSIBM.SYSDUMMY1;
10. 日期，時間形態變為字符形態:
    SELECT char(current date) FROM SYSIBM.SYSDUMMY1;
    SELECT char(current time) FROM SYSIBM.SYSDUMMY1;
    SELECT char(current date+12 hours) FROM SYSIBM.SYSDUMMY1;
11. 將字符串轉換成日期或時間形態:
    SELECT TIMESTAMP('2002-10-20-12.00.00.000000') FROM SYSIBM.SYSDUMMY1;
    SELECT TIMESTAMP('2002-10-20 12:00:00') FROM SYSIBM.SYSDUMMY1;
    SELECT DATE('2002-10-20') FROM SYSIBM.SYSDUMMY1;
    SELECT DATE('10/20/2002') FROM SYSIBM.SYSDUMMY1;
    SELECT TIME('12:00:00') FROM SYSIBM.SYSDUMMY1;
    SELECT TIME ('12.00.00') FROM SYSIBM.SYSDUMMY1;
12. 返回參數的星期几的寫法:
    SELECT DAYNAME(current timestamp) FROM SYSIBM.SYSDUMMY1;
    SELECT DAYOFWEEK(current timestamp) FROM SYSIBM.SYSDUMMY1;
    SELECT DAYOFWEEK_ISO(current timestamp) FROM SYSIBM.SYSDUMMY1;
13. 返回參數一年中的第几天的寫法:
    SELECT DAYOFYEAR(current timestamp) FROM SYSIBM.SYSDUMMY1;
14. 返回午夜和參數中指定的時間值之間的秒數的寫法:
    SELECT MIDNIGHT_SECONDS(current timestamp) FORM SYSIBM.SYSDUMMY1;
15. 返回參數中一年的第几周的寫法:
    SELECT WEEK(current timestamp) FORM SYSIBM.SYSDUMMY1