CODEWITHSUNDEEP
hibernatemappingfetchone-to-onesubquery
sergionni
sergionni

Reputation: 13530

Hibernate:can't fetch data from related one-to-one tables

There are User,Person and Employee entities.
User knows about both Person and Employee.

hibernate config for User:

...
<many-to-one name="person" class="entry.Person" column="perid" not-null="true" cascade="all"/>
<many-to-one name="employee" class="entry.Employee" column="empid" not-null="true" cascade="all"/>
...

DAO:

public List<User> getUsers() {
    return getHibernateTemplate().find("from User");
}

When fetch users with getUsers(),that Person and Employee data is NULL.

Have I missed some .hbm configuration or I should manually add more subselects to DAO?

EDIT
context:

    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource">
            <ref local="dataSource"/>
        </property>
...
    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory">
            <ref local="sessionFactory"/>
        </property>
    </bean>
    <bean id="userDao" class="dao.UserDaoHibernate">
        <property name="factory">
            <ref local="sessionFactory"/>
        </property>
    </bean>

dao:

    private SessionFactory factory;

    public void setFactory(SessionFactory factory) {
        this.factory = factory;
    }

    @Transactional
    public List<User> getUsers() {      

        Session s = this.factory.getCurrentSession();
...

got No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here,when try to execute getCurrentSession()

Upvotes: 1

Views: 859

Answers (1)

atrain
atrain

Reputation: 9265

By default, associations in Hibernate are lazy fetched unless otherwise specified in your Hibernate configuration, or initialized in code. Eager fetching in configuration is not encouraged, to avoid unexpected consequences. In your code above, you will need to explicitly initialize the Person and Employee associations.

Since you are using Spring, for coding ease you should stop using the HibernateTemplate (which hasn't been recommended to use for a while), and move over to using Hibernate directly. Then, you can use Hibernate.initialize on the associations (or some other method, like setting FetchMode) to initialize them.

Upvotes: 1

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