composite-id help

mzoom · **Joined:** Tue Feb 03, 2004 1:49 pm **Posts:** 16

i would like to have a composite-id for a table.
primary key a & b.

the first primary key -- a is a integer and "auto-increment".
the second primary key --b is assigned string.

how to do that in hibernate mapping file?

christian · **Posted:** Tue Feb 03, 2004 2:00 pm

If the integer is auto-incremented for each new record, it is a perfect primary key without the string?

greg_barton · **Posted:** Tue Feb 03, 2004 9:12 pm

Try this...

Mapping:

Code:

<hibernate-mapping default-cascade="all">
    
    <class name="foo" table="foos">
        
        <composite-id name="id" class="CompositeID" unsaved-value="any">
            <key-property name="sequenceId" type="java.lang.Long" column="sequence_id"/>
            <key-property name="stringId" type="string" column="string_id"/>
        </composite-id>

    </class>

    ....

</hibernate-mapping>

A key generator:

Code:

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Session;
import net.sf.hibernate.engine.SessionFactoryImplementor;
import net.sf.hibernate.engine.SessionImplementor;
import net.sf.hibernate.id.SequenceGenerator;
import net.sf.hibernate.type.LongType;
import java.util.Properties;

public class CompositeIDGenerator {

    private static SequenceGenerator SEQUENCE_GENERATOR =
        new SequenceGenerator();

    static {

        try {
            SEQUENCE_GENERATOR.configure(
                                         new LongType(),
                                         new Properties(),
                                         ((SessionFactoryImplementor)<!-- INSERT METHOD TO GET YOUR SESSION FACTORY HERE -->).getDialect()
                                        );
        } catch(HibernateException he) {
            //You'll want to do a bit more error checking than this, of course... :)
            he.printStackTrace();
        }
    }
    
    public static final CompositeSiteID generate(
                                                 String stringId,
                                                 Session session

                                                )
                                          throws HibernateException {

        CompositeID id = new CompositeID();
        id.setStringId(stringId);
        id.setSequenceId((Long)SEQUENCE_GENERATOR.generate(
                                                           (SessionImplementor)session,
                                                           id
                                                          )
                        );

        return id;
    }
}

Then, whenever you create an object of type foo, you've got to do this:

Code:

new Foo(CompositeIDGenerator.generate("A_STRING", session), ...)

mzoom · **Joined:** Tue Feb 03, 2004 1:49 pm **Posts:** 16

thanks -- both of you.

sag_reddy · **Joined:** Wed Feb 04, 2004 4:58 pm **Posts:** 1

Hi,

I tried to use the following hbm file
--------------------------------------------------------------------------------------
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping>
<class name="com.org.csaims.hibernate.IssueResol"
table="ISSUE_RESOL">

<composite-id name="irPK" type="com.org.csaims.pk.IssueResolPK">
<key-property name="custReqResolDate" column="CUST_REQ_RESOL_DATE" type="timestamp" length="7"/>
<key-property name="issueNum" column="ISSUE_NUM" type="string" length="8"/>
</composite-id>
<property name="projectedResolDate" column="PROJECTED_RESOL_DATE" type="timestamp" length="7"/>

</class>
</hibernate-mapping>
--------------------------------------------------------------------------------------
if i dont specify the TYPE atribute to <composite-id it gives me the xml validator exceptions.......

if i use the above file as it is and try to get data using hibernation..i get the following error when it is trying to read and configuring the file hibernate.cfg.xml the file and mapp the objects
-------------------------------------------------------------------------------------

net.sf.hibernate.MappingException: duplicate import: IssueResol
at net.sf.hibernate.cfg.Mappings.addImport(Mappings.java:82)
at net.sf.hibernate.cfg.Binder.bindClass(Binder.java:126)
at net.sf.hibernate.cfg.Binder.bindRootClass(Binder.java:217)
at net.sf.hibernate.cfg.Binder.bindRoot(Binder.java:1204)

-----------------------------------------------------------------------------------

did any one come accross the same problem,

Thanks for ur time and help in response...

greg_barton · **Posted:** Wed Feb 04, 2004 5:32 pm

Well, first of all, "type" is not an attribute of "composite-id"

Code:

<!ELEMENT composite-id ( meta*, (key-property|key-many-to-one)+ )>
  <!ATTLIST composite-id class CDATA #IMPLIED>
  <!ATTLIST composite-id name CDATA #IMPLIED>
  <!ATTLIST composite-id access CDATA #IMPLIED>
  <!ATTLIST composite-id unsaved-value (any|none) "none">

Try "class" instead.