hibernate之原生SQL那點破事entityManger和sqlquery和Session去傳回實體對象

//sql語句
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要注意實體類與資料庫字段名不能有相差，特别是資料類型，像部落客的實體就有個timestamp類型的，一直在報錯，部落客本來用的是string類型，後面經大佬指定改成了data類型就能用了！注意！如grade_person在實體類中要麼就是跟資料庫一樣的，要麼就是寫SQL的時候給個别名gradePerson，否則射不到實體類裡