Hibernate删除

Question

如何从Hibernate中删除对象？

 Session session = HibernateSession.getSessionFactory().openSession();
        org.hibernate.Transaction tx = session.beginTransaction();
        int q = session.createQuery("from Modele where (model='"+u.getModel() +"' and markaid='"+u.getMarki().getId()+"'").executeUpdate();
      //  session.delete(u);

        session.getTransaction().commit();

信息：不支持！使用AST翻译......

使用session.delete(u)代替我

INFO：在删除处理中处理瞬态实体

CREATE TABLE modele
(
  id serial NOT NULL,
  markaid integer NOT NULL,
  cena numeric(100,2),
  model character varying(32),
  CONSTRAINT k_glwny PRIMARY KEY (id),
  CONSTRAINT obcy FOREIGN KEY (markaid)
      REFERENCES marki (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE CASCADE
)

<hibernate-mapping>
    <class name="bazaMap.Modele" table="modele" schema="public">
        <id name="id" type="int">
            <column name="id" />
            <generator class="identity" />
        </id>
        <many-to-one name="marki" class="bazaMap.Marki" fetch="select">
            <column name="markaid" not-null="true" />
        </many-to-one>
        <property name="cena" type="java.lang.Double">
            <column name="cena" scale="0" />
        </property>
        <property name="model" type="string">
            <column name="model" length="32" />
        </property>
        <set name="wypozyczenias" inverse="true">
            <key>
                <column name="modelid" not-null="true" />
            </key>
            <one-to-many class="bazaMap.Wypozyczenia" />
        </set>
    </class>
</hibernate-mapping>

这也不起作用

session.createQuery("from Modele where model = :mmodel and markaid = :mmarkaid").setParameter("mmodel", u.getModel()).setParameter("mmarkaid", u.getMarki().getId()).executeUpdate();

Answer 1

我相信您的HQL缺少导致AST错误的DELETE关键字（基本上是HQL语法错误。）它应该是：

DELETE from Modele where (model='"+u.getModel() +"' and markaid='"+u.getMarki().getId()+"'"

如果你想使用delete方法（在hibernate 3中实际上不赞成使用HQL），你必须确保在删除它之前将实体加载到你删除它的同一个会话中。

我通常使用HQL样式删除，但我建议使用命名参数而不是字符串连接。