Hibernate Mapping : delete children in one to many bidirectional mapping in hibernate

Question

I have a parent object and its detail object. The mappings are mentioned in the below code -

Parent Object Mapping

    <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class lazy = "false" name="com.test.model.Parent" table="parent">
        <id name="parentId" column="PARENT_ID" type="long">
            <generator class="sequence">
                <param name="sequence">PARENT_ID_SEQ</param>
            </generator>
        </id>
        <set 
            name="childSet" 
            lazy="false" 
            cascade="all-delete-orphan" 
            inverse="true" 
            table = "child" 
            order-by = "CHILD_ID"
            >
            <key column="PARENT_ID"/>
            <one-to-many class="com.test.model.Child"/>
        </set>
    </class>
</hibernate-mapping>

Child Object mapping

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="com.test.model.Child" table="hot_Cash_coupon">
        <id name="childId" column="CHILD_ID" type="long">
            <generator class="sequence">
                <param name="sequence">CHILD_ID_SEQ</param>
            </generator>
        </id>
        <many-to-one name="parent"
            class="com.test.model.Parent" column="PARENT_ID" not-null="true" />
    </class>
</hibernate-mapping>

I am able to save a new parent with say 3 childrens. Now, in the update operation,

In parent.childSet, I am removing all values and setting new values. When I do session.update(parent), my requirement is to,

Delete all the existing children for the parent - as the parent.childSet doesn't have them.
Insert the new values that are available in parent.childSet.

here, parent.childSet means, the Set in Parent Class/HBM Mapping.

The problem happening now is,

It is throwing exception - "cannot insert NULL into ("CHILD"."PARENT_ID")"

I will keep updating the question if it is not clear.

Thanks for your time!

Can u post code snippet how you are deleting existing children and adding new children — Ramesh, Feb 10 '15 at 09:01
@Ramesh It is a simple get Parent object from Data Access Layer. Then, a simple java operation to clear the childSet object in Parent object. Then adding new values to the childSet using Collection add. Actually the values are coming from UI, so each time we are clearing the childSet and adding fresh childs on each update. — Koushik Roy, Feb 10 '15 at 10:23
Refer this Question http://stackoverflow.com/questions/12568503/hibernate-does-not-delete-orphans-on-onetomany — Ramesh, Feb 10 '15 at 11:31
There is no clear answer of this problem and moreover I am using hbm xml for mapping. — Koushik Roy, Feb 11 '15 at 06:21
No the problem is not in mapping . Problem might be in java code . Refer to Diego Pino answer in that question . It might help . else post java code i will say where to correct it — Ramesh, Feb 11 '15 at 06:42

score 0 · Accepted Answer · answered Feb 11 '15 at 06:24

0

For the time being I am doing an session.update(parent). Which nullify the foreign keys and orphan records exist in the CHILD table. And there after I do a session.delete(...) of the orphans manually.

This is more of a workaround than a solution.

answered Feb 11 '15 at 06:24

Koushik Roy

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Hibernate Mapping : delete children in one to many bidirectional mapping in hibernate

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