Hi,
I am using hibernate 2.0. I would like to know how to Map composite Key using the Hibernate.
I am having one Database Table named RevenueAttributeLink in that I am having two Columns "revenueId" and "revenueattributeId" these two are composite key.
My hibernate mapping XML I have written like this.I am using this Table to read the values returned from this table.

*****************************************************
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="au.com.combined.domain.revenue.RevenueAttributeLinkBusinessObject" table="RevenueAttributeLink">
<composite-id>
<key-property name="revenueID" type="long" column="revenueID" unsaved-value="0" />
<key-property name="revenueAttributeID" type="long" column="revenueID" unsaved-value="0" />
<generator class="assinged">
</generator>
</composite-id>
</class>
</hibernate-mapping>
*********************************************************
After running I am getting following errors.Please let me know if I need to modify the Mapping XML.
*************************************************

[29/08/05 21:51:39:426 EST] 11d711d7 XMLHelper E net.sf.hibernate.util.XMLHelper Error parsing XML: XML InputStream(8) Attribute "unsaved-value" must be declared for element type "key-property".

[29/08/05 21:51:39:442 EST] 11d711d7 XMLHelper E net.sf.hibernate.util.XMLHelper Error parsing XML: XML InputStream(9) Attribute "unsaved-value" must be declared for element type "key-property".

[29/08/05 21:51:39:442 EST] 11d711d7 XMLHelper E net.sf.hibernate.util.XMLHelper Error parsing XML: XML InputStream(12) The content of element type "composite-id" must match "(meta*,(key-property|key-many-to-one)+)".
ERROR [endeavour.core ] HibernateSessionFactory::<clinit>: Problem building hibernate session factory
net.sf.hibernate.MappingException: Error reading resource: au/com/combined/persistence/billing/RevenueAttributeLink.hbm.xml

**************************************************************

Remove the generator element.

Composite keys can ONLY be assigned, so you don’t need to instruct Hibernate this.

It didn't solve the problem..I am getting the Same Error.


org.xml.sax.SAXParseException: Attribute "unsaved-value" must be declared for element type "key-property".

The unsaved-value can only be "undefined|any|none"

See:
http://www.hibernate.org/hib_docs/v3/reference/en/html/mapping.html#mapping-declaration-compositeid

I have set it to "none".
Will it help me while updating the table.If I want to insert the data into the same table.

We are using composite keys in our solution, and we don’t specify any unsaved-value in our maps (default is undefined). The application is designed to always assign a value to the object before it is passed on to Hibernate for persisting.

Was that an answer to your question??

Yeah after removing that worked...But now I am getting Classcast exception...

I am getting folowing Exception
*************************************************
[30/08/05 00:50:42:585 EST] 1ce11ce1 SystemErr R au.com.combined.core.SystemException: java.lang.ClassCastException: java/lang/Long incompatible with au/com/combined/domain/revenue/RevenueAttributeLinkBusinessObject
[30/08/05 00:50:42:648 EST] 1ce11ce1 SystemErr R at java.lang.Throwable.<init>(Throwable.java:59)
[30/08/05 00:50:42:648 EST] 1ce11ce1 SystemErr R at java.lang.Throwable.<init>(Throwable.java:104)
[30/08/05 00:50:42:648 EST] 1ce11ce1 SystemErr R at au.com.combined.core.WrappedMessageException.<init>(WrappedMessageException.java:76)
[30/08/05 00:50:42:648 EST] 1ce11ce1 SystemErr R at au.com.combined.core.SystemException.<init>(SystemException.java:60)
[30/08/05 00:50:42:648 EST] 1ce11ce1 SystemErr R at au.com.combined.persistence.HibernatePersistenceImpl.read(HibernatePersistenceImpl.java)
*************************************************************
Throwing Error on this particular line in the code.

BusinessObject object = (BusinessObject) session.get(klass, new Long(id));

It is getting the klass as a RevenueAttributeLinkBusinessObject.class and
new Long(id) as 4449.

Do I need to modify my Mapping Xml or business object.the business object is having equals and hashcode methods in it like this.
**********************************
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof RevenueAttributeLinkBusinessObject)) {
return false;
}
RevenueAttributeLinkBusinessObject that = RevenueAttributeLinkBusinessObject) o;
return(this.revenueID == that.revenueID);
}
*************************************
public int hashCode() {
HashCode hash = new HashCode();
hash.add(revenueID);
hash.add(revenueAttributeID);
return hash.hashCode();
}

I don’t think your can query the way you are doing (Take a look at the API for sessiong.get(....))

We are using criteria which would give something like this:


Good luck

Just want to know weather my Mapping Xml is right or
I have to change it
*************************************************
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="au.com.combined.domain.revenue.RevenueAttributeLinkBusinessObject" table="biRevenueAttributeLink">
<composite-id>
<key-property name="revenueID" type="long" column="revenueID" />
<key-property name="revenueAttributeID" type="long" column="revenueAttributeID" />
</composite-id>
</class>
</hibernate-mapping>
****************************************************
Equal and Hash code implementation in my Business Object.

****************************************************

public boolean equals(Object o) {
if (this == o) {
return true;
}

if (!(o instanceof RevenueAttributeLinkBusinessObject)) {
return false;
}
RevenueAttributeLinkBusinessObject that = (RevenueAttributeLinkBusinessObject) o;
return(this.revenueID == that.revenueID && this.revenueAttributeID == that.revenueAttributeID);

}
****************************************************
public int hashCode() {
HashCode hash = new HashCode();
hash.add(revenueID);
hash.add(revenueAttributeID);
return hash.hashCode();
}