今天遇到这个错误，网上查了下，大多说是有必填字段没有填，搞了很久没搞定，最后发现不是因为这个问题，而是因为字段设置了唯一值，如果表中已存在此记录，再插入则报此错误。
Hibernate: insert into membership.t_user (login_id, password, type, status, email, mobile, first_name, last_name, nickname, gender, birthday, country, region, creation_date, last_update_date, join_confirm_date, activation_date, deactivation_date, register_code, join_expire_date) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
org.springframework.dao.DataIntegrityViolationException: could not insert: [com.igen6.sac.ms.bean.TUser]; SQL [insert into membership.t_user (login_id, password, type, status, email, mobile, first_name, last_name, nickname, gender, birthday, country, region, creation_date, last_update_date, join_confirm_date, activation_date, deactivation_date, register_code, join_expire_date) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not insert: [com.igen6.sac.ms.bean.TUser]