1 日期格式的用法
SQL> select to_char(sysdate,'fmDdthsp "of" Month,year') from dual;
TO_CHAR(SYSDATE,'FMDDTHSP"OF"M----------------------------------------------------------------------Sixth of September,twenty thirteen
2 trim/fm(to_char(sysdate,'yyyy')) 能够取出日期类型前后的空格
fx是匹配精确时间类型 很少用