Question

我正在学习使用Spring＆amp;冬眠。现在我在hibernate中遇到了许多关系的问题。我的数据没有保存在jon表中。我不知道为什么。请有人帮帮我我有两个域类叫做Projects＆amp;技术。
这是我在这两个班级中的映射项目类： -

@ManyToMany
@JoinTable(name="project_technology",
        joinColumns={@JoinColumn(name="projectId")},
        inverseJoinColumns={@JoinColumn(name="technologyId")})
public List<Technology> getTechnology() {
    return technology;
}

技术课： -

@ManyToMany
@JoinTable(name="project_technology",
            joinColumns={@JoinColumn(name="technologyId")},
            inverseJoinColumns={@JoinColumn(name="projectId")})
public List<Projects> getProjects() {
    return projects;
}

在我的DAo图层

getSession().beginTransaction();
getHibernateTemplate().save(projects);
getHibernateTemplate().clear()

用于保存数据。它没有显示错误，但数据未保存在连接表中。

当我使用

时

Session session = getSession();
Transaction transaction = session.beginTransaction();
session.save(projects);
transaction.commit();
session.close();

保存，数据正确保存在连接表中。但保存后我得到了这个错误

org.springframework.transaction.TransactionSystemException: Could not commit Hibernate transaction; nested exception is org.hibernate.TransactionException: Transaction not successfully started

我的applicationcontext.xml

<bean id="mySessionFactory"
    class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="dataSource" ref="hibernateDataSourse" />
    <property name="annotatedClasses">
        <list>              
            <value>com.sla.tecprof.domain.Technology</value>            
        </list>
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect"> org.hibernate.dialect.MySQLDialect</prop>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
        </props>
    </property>
</bean>

<bean id="transactionProxy"
    class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"
    abstract="true" lazy-init="true">
    <property name="transactionManager" ref="hibernateTransactionManager" />
    <property name="transactionAttributeSource" ref="transactionAttributeSource" />
    <property name="preInterceptors">
        <list>
            <ref bean="exceptionInterceptor" />
            <ref bean="TransactionPointCutAdvisor" />
        </list>
    </property>

    <property name="postInterceptors">
        <list>
            <ref bean="hibernateInterceptor" />
        </list>
    </property>

    <property name="proxyTargetClass" value="true" />
</bean>

Answer 1

您应该只在一侧使用@JoinColum Annotation。

@ManyToMany
@JoinTable(name="project_technology",
        joinColumns={@JoinColumn(name="projectId")},
        inverseJoinColumns={@JoinColumn(name="technologyId")})
public List<Technology> getTechnology() {
    return technology;
}

@ManyToMany(fetch = FetchType.LAZY, mappedBy = "technology")
public List<Projects> getProjects() {
    return projects;
}

Hibernate注释的重要资源：http://www.mkyong.com/hibernate/hibernate-many-to-many-relationship-example-annotation/

Answer 2

我找到了解决方案。这就是我在DAO leyer中所做的事情

Session session = getHibernateTemplate().getSessionFactory().openSession();
        Transaction transaction = session.beginTransaction();
        session.save(projects);
        transaction.commit();
        session.close();

Hibernate很多很多关系都不起作用

2 个答案: