Cascading update problem

[John Utting]

Hi, I am doing some little tests to understand some of the behaviour of hibernate (v3.1) and would like some advice.

I have a bidirection parent child relationship as follows:

parent.hbm.xml

<hibernate-mapping>
 
    <class name="parent.Parent" table="PARENT" schema="DIRTY">
    
        <id name="id" column="PARENTID">
            <generator class="native"/>
        </id>
        
        <version name="versionNumber" column="VERSION" type="timestamp"/>
        
        <property name="name" column="NAME"/>
                
        <set name="children" 
        inverse="true"
        lazy="false"
        cascade="all">
        <key column="PARENTID"/>
        <one-to-many class="child.Child"/>
    </set>
    
    </class>
 
</hibernate-mapping>

child.hbm.xml

  
    <class name="child.Child" table="CHILD" schema="DIRTY">
    
        <id name="id" column="CHILDID">
            <generator class="native"/>
        </id>
        
        <version name="versionNumber" column="VERSION" type="timestamp"/>
        
        <property name="name" column="NAME"/>
        
        <many-to-one name="parent"
        lazy="false"
        class="parent.Parent"
        not-null="true"
        column="PARENTID">
        </many-to-one>
        
    </class>

Parent.java

  
public class Parent {
 
.............
.............    
    
    public void addChild(Child child){
        child.setParent(this);
        children.add(child);
    }
.............
.............
 
}

I open a session and get a parent from the database and any chilren are eagerly fetched (ignore the fact that i am eagerly loading a collection this is for a test only). Session closed.

I then create a new child and add it to the parent. Then, in a new Session, update the parent object, resulting in the transient child being persisted. All well and good.

The behaviour i am also seeing is that hibernate is updating all the children even though their state has not changed.

I understand that instead of updating the parent i could save the child and this would prevent the other children being updated. What i would like to know is their a way of configuring hibernate or the relationship so that i can update the parent and persist new children without hibernate firing updates on all the other children.

Any help would be greatly appreciated.

Thanks
John