如题， 执行insert前， 实体对象有些属性值为null, 调用insert()方法后，打出来的sql给这些空值自动加了单引号，类似这样：

org.nutz.dao.DaoException: !Nutz SQL Error: 'INSERT INTO YDM_PLEDGE_INFO(ID,CUSTOMER_CERT_ID,CUSTOMER_NAME,PLEDGE_ID,GUARANTY_TYPE,PLEDGE_TYPE,OWNER_NAME,PLEDGE_START_DATE,PLEDGE_END_DATE,PLEDGE_EVALUATE_VALUE,BUSINESSSUM,SIGN_DATE,SIGN_ORGAN,description,BELONG_ORGAN,POCKET_ORIGINAL_NO,POCKET_RECENT_NO,ARCHIVES_NO,state,IN_STORAGE_DATE,INPUT_TYPE,REVERT_DATE,BORROW_USER_NAME) VALUES('','','333','2015112400000006','3772ECABB40E4409871C96C4430FFC40','21CBEF87CF754CB4BC06E2224AC1751F','','NULL','NULL','NULL','NULL','NULL','','','','NULL','NULL','010101001','1','2017-11-01 18:09:34','1','NULL','NULL') '

看下是不有这个BUG