hibernate之原生SQL那点破事entityManger和sqlquery和Session去返回实体对象

//sql语句
String str="select id,songname,songid,create_time as createTime,grade_person as gradePerson,grade_person_id as gradePersonId,remark  from tb_grade where songname='"+songName+"' and songid= "+songId+" and grade_person='"+u.getNickName()+"' and grade_person_id="+u.getId();
			

			Session session = entityManager.unwrap(org.hibernate.Session.class);
			SQLQuery query = session.createSQLQuery(str);
            Grade grade = null;


            //方法1
			query.setResultTransformer(Transformers.aliasToBean(Grade.class));
			List<Grade> lists = query.list();
            grade=lists.get(0);

            //方法2
			query.setResultTransformer(Transformers.TO_LIST);
			List<Grade> lists = query.addEntity(Grade.class).list();
			grade=lists.get(0);
           

方法2要注意实体类与数据库字段名不能有相差，特别是数据类型，像博主的实体就有个timestamp类型的，一直在报错，博主本来用的是string类型，后面经大佬指定改成了data类型就能用了！注意！如grade_person在实体类中要么就是跟数据库一样的，要么就是写SQL的时候给个别名gradePerson，否则射不到实体类里