Oracle获取当前时间

SQL>  select to_char(sysdate,'yyyy-MM-dd-hh-mm-ss') from dual;
TO_CHAR(SYSDATE,'YY ------------------- 2011-12-28-08-12-12
SQL>  select to_char(current_timestamp,'yyyy-MM-dd-hh-mm-ss') from dual;
TO_CHAR(CURRENT_TIM ------------------- 2011-12-28-08-12-47