数据库字段是varchar2(20)存放的是数据是（ 2012-05-31 23:11:12 ），也有可能是NULL
我现在怎么取数据，如果有数据就格式为YYYYMMDDH24MISS 如果是NULL 转为0
用SQL语句实现
------解决方案--------------------
- SQL code
with t1 as( select '2012-05-31 23:11:12' c1 from dual union all select '' c1 from dual union all select '2012-05-22 22:22:22' c1 from dual )select nvl(to_char(to_date(c1,'yyyy-mm-dd hh24:mi:ss'),'yyyymmddhh24miss'),0) c1from t1 c1------------------------1 201205312311122 03 20120522222222