关于SessionFactory

public static void main(String args[]){



	        SessionFactory sf = new Configuration()   

	            .setProperty("hibernate.connection.driver_class", "com.mysql.jdbc.Driver")   

	            .setProperty("hibernate.dialect", "org.hibernate.dialect.MySQLDialect")   

	            .setProperty("hibernate.connection.url", "jdbc:mysql://localhost/huayi?useUnicode=true&characterEncoding=latin1")   

	            .setProperty("hibernate.connection.username", "root")   

	            .setProperty("hibernate.connection.password", "root")   

//	          .setProperty("hibernate.hbm2ddl.auto", "create")   

//	          validate               加载hibernate时，验证创建数据库表结构   

//	          create                  每次加载hibernate，重新创建数据库表结构，这就是导致数据库表数据丢失的原因。   

//	          create-drop        加载hibernate时创建，退出是删除表结构   

//	          update                 加载hibernate自动更新数据库结构   

//	            .addAnnotatedClass(Order.class)   

//	            .addAnnotatedClass(Item.class)   

	            .buildSessionFactory();   

	           

	        Session session = sf.openSession();   

	        session.beginTransaction();   

	        List result = session.createQuery("from PlcAmsNetID").list();   



	  	        session.getTransaction().commit();   

	           	        System.out.println("done...");   

	    } 	  

提示
Exception in thread "main" org.hibernate.hql.ast.QuerySyntaxException: PlcAmsNetID is not mapped [from PlcAmsNetID]
at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:158)
at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:87)
at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:70)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:2