Hi,
I am new to Hibernate and have been looking for almost two days for a solution and still had no luck.
Can someone give me a small example as how to copy all the child elements from parent1 to parent2. Note: Parent2 is transient, not yet updated to the database, children are of type bag.



Can someone tell me what I am doing wrong? I get a NonUniqueException when I try to Save.

Thanks for any help,
Javid

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Read this: http://hibernate.org/42.html

Can you post your mapping files ? Looks like a problem with your collection mapping. Hay your tried a many-to-many mapping ?

Wolfgang

Thanks for your response. Here are my mapping files:

Parent : Template.hbm.xml
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0"
namespace="HaynesPrototype" assembly="HaynesPrototype">
<class name="HaynesPrototype.Template" table="SCENARIO_TEMPLATES">
<id name="ID" column="ID" unsaved-value="0" type="integer" length="50">
<generator class="identity" />
</id>
<property name="TemplateName" column="TEMPLATE_NAME" type="string" length="40" />
<bag name="TemplateValues" table="SCENARIO_TEMPLATE_VALUES" access="property"
inverse="true" lazy="true" cascade="all-delete-orphan">
<key column="TEMPLATE_ID" />
<one-to-many class="TemplateValue" />
</bag>

</class>

Child: TemplateValue.hbm.xml
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0"
namespace="HaynesPrototype" assembly="HaynesPrototype">
<class name="HaynesPrototype.TemplateValue" table="SCENARIO_TEMPLATE_VALUES">
<composite-id>
<key-many-to-one name="Parent" class="Template">
<column name="TEMPLATE_ID" />
</key-many-to-one>
<key-property name="Type" column="TYPE" type="string" />
<key-property name="Value" column="VALUE" type="string" />
</composite-id>
<many-to-one name="Parent" class="Template" column="TEMPLATE_ID" insert="false" update="false" not-null="true" />
</class>


</hibernate-mapping>

Thanks for your help

Javid

Hi Javid,

I've misunderstood your question in the first place. Thought you want to attach the same child to another parent. Considering your second post to this problem, you really want to make a deep copy.
I haven't used composite ids yet, so I can only guess. As far as I understood composite ids from studying the reference, you have to implemented Equals and GetHashCode in TemplateValue. It also needs to be Serializable [from reference 5.1.5]. If not, Hibernate could probably not decide, if you new instance is unsaved. Have a look at the reference chapter 7.4, too.

Why don't you use a generated id on TemplateValue instead of a composite id that contains all columns of the table. You can use the generated id as primary key and define a unique constraint on (parentid, type,value).

Hope that helps,
Wolfgang

Hi wolfgang,
Thanks for your response. I found the problem, my GethashCode() was not implemented right, so it's working fine now.

Thanks again,
Javid