一、mysql表结构中存在如下设计时
表结构中updated_time设计为ON UPDATE CURRENT_TIMESTAMP时，如下
`updated_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间';
二、使用过程的一个坑即存在的问题：
当update整个dao实体对象时，又没有将该对象中的updateTime字段设置为null或new date();
update time不会更新为最新时间
三、解决方式
1.调用xxxDAO的update方法时，update的对象中存在update time(更新时间)时，请手动set一个 new Date() 或 null;
2. BeanUtils.copyProperties(form, tConsultant,"updateTime"); copy的复制可以指定要忽略的updateTime字段
spring中该方法的源码如下：
/**
* Copy the property values of the given source bean into the given target bean,
* ignoring the given "ignoreProperties".
* <p>Note: The source and target classes do not have to match or even be derived
* from each other, as long as the properties match. Any bean properties that the
* source bean exposes but the target bean does not will silently be ignored.
* <p>This is just a convenience method. For more complex transfer needs,
* consider using a full BeanWrapper.
* @param source the source bean
* @param target the target bean
* @param ignoreProperties array of property names to ignore
* @throws BeansException if the copying failed
* @see BeanWrapper
*/
public static void copyProperties(Object source, Object target, String... ignoreProperties) throws BeansException {
copyProperties(source, target, null, ignoreProperties);
}