Updating problem

kash_meu · **Posted:** Wed May 07, 2008 6:22 pm

Hi All!

I am having problem with updating the records. When I try to call update or saveOrUpdate function, hibernate exception raises with this message

a different object with the same identifier value was already associated with the session

I am very much concerned with the problem. Please somebody help me. Thanks in advance

Sukirtha · **Posted:** Thu May 08, 2008 12:54 am

That is because you are trying to update a detached object. You could do a merge() before update. Or even better, update the object in the session instead of doing a detached object update.

waswani · **Posted:** Thu May 08, 2008 1:09 am

Please provide the xml mapping and the java code wgere u r updating the entitiy.

kash_meu · **Posted:** Thu May 08, 2008 4:18 pm

Sukirtha wrote:

That is because you are trying to update a detached object. You could do a merge() before update. Or even better, update the object in the session instead of doing a detached object update.

This is the body of the update function in the DAO class

org.hibernate.Transaction tx=getSession().beginTransaction();
getSession().update(instance);
tx.commit();

What does it mean by detaching objects and attaching objects?

kash_meu · **Posted:** Thu May 08, 2008 4:24 pm

waswani wrote:

Please provide the xml mapping and the java code wgere u r updating the entitiy.

Code:

<hibernate-mapping>
    <class name="lacarte.persistence.User" table="user" catalog="lacarte">
        <id name="userId" type="java.lang.Integer">
            <column name="userId" />
            <generator class="increment" />
        </id>
        <many-to-one name="company" class="lacarte.persistence.Company" fetch="select">
            <column name="companyId" />
        </many-to-one>
        <property name="userName" type="java.lang.String">
            <column name="userName" />
        </property>
        <property name="password" type="java.lang.String">
            <column name="password" />
        </property>
        <property name="firstName" type="java.lang.String">
            <column name="firstName" />
        </property>
        <property name="lastName" type="java.lang.String">
            <column name="lastName" />
        </property>
        <property name="address" type="java.lang.String">
            <column name="address" />
        </property>
        <property name="zip" type="java.lang.String">
            <column name="zip" />
        </property>
        <property name="city" type="java.lang.String">
            <column name="city" />
        </property>
        <property name="state" type="java.lang.String">
            <column name="state" />
        </property>
        <property name="country" type="java.lang.String">
            <column name="country" />
        </property>
        <property name="type" type="java.lang.Integer">
            <column name="type" />
        </property>
        <property name="phone" type="java.lang.String">
            <column name="phone" />
        </property>
        <set name="companies" inverse="true">
            <key>
                <column name="userId" />
            </key>
            <one-to-many class="lacarte.persistence.Company" />
        </set>
        <set name="transactions" inverse="true">
            <key>
                <column name="userId" />
            </key>
            <one-to-many class="lacarte.persistence.Transaction" />
        </set>
    </class>
</hibernate-mapping>

This is my mapping file for the User Bean

Sukirtha · **Posted:** Fri May 09, 2008 12:24 am

Quote:

What does it mean by detaching objects and attaching objects?

I am sure you are doing a retrieve before you start modifying the object. But somewhere in between the retrieve and update() method call, you are closing the session and re-opening it for update. Once a session closes, the retrieved object becomes detached. There are ways to handle detached object update. One such way is merge() instead of saveOrUpdate() or update().

Refer Hibernate_reference.pdf section 10.6
http://www.hibernate.org/hib_docs/reference/en/pdf/hibernate_reference.pdf

kash_meu · **Posted:** Fri May 09, 2008 4:51 am

Quote:

I am sure you are doing a retrieve before you start modifying the object. But somewhere in between the retrieve and update() method call, you are closing the session and re-opening it for update. Once a session closes, the retrieved object becomes detached. There are ways to handle detached object update. One such way is merge() instead of saveOrUpdate() or update().

Refer Hibernate_reference.pdf section 10.6
http://www.hibernate.org/hib_docs/reference/en/pdf/hibernate_reference.pdf

[/quote]

There is another problem when I use merge(). I lose the associations when I merge() the object.

Sukirtha · **Posted:** Fri May 09, 2008 5:52 am

Quote:

There is another problem when I use merge(). I lose the associations when I merge() the object.

I guess that is because you have not explicitly asked to cascade the relationships during a merge/save-update operations.

include cascade="merge, save-update" in <set> collections in your mapping file.

i.e.,

Code:

        <set name="companies" inverse="true" cascade="merge, save-update">         
        <key> 
               <column name="userId" /> 
         </key> 
            <one-to-many class="lacarte.persistence.Company" /> 
        </set> 
        <set name="transactions" inverse="true" cascade="merge,save-update"> 
            <key> 
                <column name="userId" /> 
            </key> 
            <one-to-many class="lacarte.persistence.Transaction" /> 
        </set> 