composite-id auto-generation

hfhuifei · **Joined:** Thu Sep 11, 2008 1:05 am **Posts:** 1

HibernateMapping:

<composite-id name="id" class="TbPatientId">
<key-property name="researchId" type="int">
<column name="research_id" />
</key-property>

<key-property name="centerId" type="int">
<column name="center_id" />
</key-property>

<key-property name="patientId" type="int">
<column name="patient_id" />
</key-property>
</composite-id>

DB Rows:
research_id | center_id | patient_id
1 | 1 | 1
1 | 1 | 2
1 | 2 | 1
1 | 2 | 2
1 | 2 | 3

Problem:
newbie question: To insert a new patient for a specific research_id and center_id, how can I auto-increment the patient_id using Hibernate? For example: to insert a new patient for research_id=1 and center_id=2, I need to automatically increment patient_id to 4, how to do that with hibernate <generator> or something else similar?

Thanks

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

Yes, create a class implementing the Hibernate generator, to which you can pass parameters indicating how you would icrement.

It is detailed here
http://www.hibernate.org/hib_docs/refer ... pping.html
(section 5.1.4.1. Generator)

jaalex · **Joined:** Mon May 19, 2008 12:42 am **Posts:** 10

Hi,

Can you please elaborate on how the <generator> will be used for composite PK?. In my situation (see hbm below) XYZ_REQUEST_ID needs to be auto-generated from xyz.sequence_application_id sequence, and XYZ_REQUEST_SITE_ID is supplied by the application.

Code:

    <class name="com.xyz.entity.Request"
        table="XYZ_REQUEST" schema="XYZ">
        <composite-id>
        
              <key-property name="rqSiteId"
                  type="java.lang.String">
                  <column name="XYZ_REQUEST_SITE_ID" length="1" not-null="true" />
              </key-property>
              <key-property name="rqId" type="java.lang.Integer">
                  <column name="XYZ_REQUEST_ID"  />
              </key-property>

            <generator class="org.hibernate.id.enhanced.SequenceStyleGenerator">
            <param name="sequence_name">xyz.sequence_application_id</param>
            <param name="initial_value">1</param>
            <param name="increment_size">1</param>
            </generator>               
        </composite-id>   

The exception says :

Code:

org.hibernate.id.IdentifierGenerationException: this id generator generates long, integer, short
   at org.hibernate.id.IdentifierGeneratorFactory.createNumber(IdentifierGeneratorFactory.java:167)
   at 

How do we specify that only for one of the key-property we need to use the generator?

cbila · **Joined:** Thu Mar 01, 2012 7:24 am **Posts:** 1

I have exactly the same problem, is there any solution ?

Thanks for advice.