查询某月有多少天.代码例如以下: select to_number(add_months( trunc(to_date('2014-11-4 11:13:53','yyyy-mm-dd hh24:mi:ss'),'mm'),1) - trunc(to_date('2014-11-4 11:13:53', 'yyyy-mm-dd hh24:mi:ss'),'mm')) daycount from dual; select to_number(add_months( trunc(to_date(to…