ORACLE单行函数与多行函数之四：日期函数示例(三)
ad precision specifier
10.使用TRUNC:对日期进行截取
BYS@bys1>set linesize 200
BYS@bys1>select trunc(sysdate,'yy') as year,trunc(sysdate,'mm') as month,trunc(sysdate,'dd') as day,trunc(sysdate,'hh') as hour,trunc(sysdate,'hh24') as hour24,trunc(sysdate,'mi') as minutes from dual;
YEAR MONTH DAY HOUR HOUR24 MINUTES
------------------- ------------------- ------------------- ------------------- ------------------- -------------------
2013/01/01 00:00:00 2013/11/01 00:00:00 2013/11/02 00:00:00 2013/11/02 18:00:00 2013/11/02 18:00:00 2013/11/02 18:52:00
只能截取年、月、日、时、分；不能截取秒。
BYS@bys1>
select trunc(sysdate,'ss') as sss from dual;
select trunc(sysdate,'ss') as sss from dual
*
ERROR at line 1:
ORA-01899: bad precision specifier