带注释的hibernate中的查询

Question

当我尝试用hibernate完成select时，抛出了这个异常：

org.hibernate.hql.internal.ast.QuerySyntaxException: formato is not mapped [from formato]
    at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
    at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
    at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93)
    at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:324)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3420)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3309)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
    at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)

我检查了我的对象注释，并认为它是好的，这是代码：

@Entity
@Table(name="formato")
public class Formato implements Serializable{

    /**
     * 
     */
    private static final long serialVersionUID = 5849413670083213438L;
    @Id
    @Column(name="id")
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int id;
    @Column(name="formato")
    private String formato;
    @Column(name="tipoItem")
    private int tipoItem;

在BD中，属性具有相同的名称

显然放了getter和setter，还有我的DAO：

@Transactional
    public List<Formato> findAllFormatos() {
        Transaction tx = null;
        session = sessionFactory.getCurrentSession();
        try {
            tx = session.beginTransaction();
            List formatos = session.createQuery("from formato").list();
            System.out.println("Pase :'D");
            tx.commit();
            return formatos;

        } catch (Exception e) {
            // TODO: handle exception
            if (tx != null) tx.rollback();
            e.printStackTrace();
            return null;
        }


    }

最后是控制器，但我认为问题出在DAO中

@RequestMapping(value = "timbre", method = RequestMethod.GET)
    public String redirigir(@RequestParam("id") int id, Model model) {

        Timbre t = null;
        if (id == 1){
            t = new Timbre();
            model.addAttribute("t", t);

            List<Formato> formatos= timbreDAO.findAllFormatos();
            model.addAttribute("formatos", formatos);


            return "formTimbre";

        }   
        else if (id == 2)
            return "modificarTimbre";
        else if (id == 3)
            return "eliminarTimbre";
        else if (id == 4)
            return "buscarTimbre";
        else
            return "timbre";

    }

Answer 1

在HQL中，您应该使用映射的@Entity的java类名和属性名，而不是实际的表名和列名，因此HQL应该是：

List<Formato> formatos = (List<Formato>)session.createQuery("from Formato").list();

Answer 2

如果您没有在SessionFactory中声明带注释的实体，则会得到该异常。如果您使用的是spring，那么在sessionFactory Bean中指定以下内容。它也可能是.cfg文件。

<property name="annotatedClasses">
         <list>
 <value>com.somefolder.Formato</value>
</list>
</property>