1.select trunc(sysdate) from dual
2.select trunc(sysdate, ‘mm‘) from dual
3.select trunc(sysdate,‘yy‘) from dual
4.select trunc(sysdate,‘dd‘) from dual
5.select trunc(sysdate,‘yyyy‘) from dual
6.select trunc(sysdate,‘d‘) from dual
7.select trunc(sysdate, ‘hh‘) from dual
8.select trunc(sysdate, ‘mi‘) from dual
原文:http://www.cnblogs.com/yasun/p/3956558.html