org.hibernate.HibernateException: The database returned no natively generated identity value

problem

使用hibernate新增数据报错

org.hibernate.HibernateException: The database returned no natively generated identity value

reason

table的字段id不是自增特性

solution

设置id为自增特性

-- 将id字段设置为主键，不为空，自增即可
alter table User modify id int(11) not Null auto_increment primary key;