db2中也有一个类似于oracle中的dual表的系统表是：sysibm.sysdummy1
功能也类似，例如：
select current date from sysibm.sysdummy1
select current timestamp from sysibm.sysdummy1
select 100 as value1 from sysibm.sysdummy1
——————————————————————————————————————————————
习惯了使用dual或者表名难记，可以建立一个视图方便查询系统数据：
create view dual as select IBMREQD as DUMMY from SYSIBM.SYSDUMMY1
应用举例：
select current timestamp from dual
select to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') as nowTime from dual;
select to_char(sysdate,'yyyy') as nowYear from dual; //获取时间的年
select to_char(sysdate,'mm') as nowMonth from dual; //获取时间的月
select to_char(sysdate,'dd') as nowDay from dual; //获取时间的日
select to_char(sysdate,'hh24') as nowHour from dual; //获取时间的时
select to_char(sysdate,'mi') as nowMinute from dual; //获取时间的分
select to_char(sysdate,'ss') as nowSecond from dual; //获取时间的秒
延伸阅读：
http://blog.csdn.net/lpioneer/article/details/5940366
http://blog.csdn.net/dada360778512/article/details/6170580
