Changing a collection "off-session" and saving.

olas · **Joined:** Tue Dec 16, 2003 9:57 am **Posts:** 13

Hi,
I'm using Hibernate 2.1.1, Windows 2000, Jdk 1.3 and DB2 7.2. I am trying to do the following:

I have a Case object with a set of Involved objects (persons involved in the case). From a web application, I create, changes and retrieves Cases. All saving and retrival happens i a stateless session bean, so the session used when saving is different from the session uses when retrieving a Case.

I have run into trouble when I try to change the set of Involved objects. Here's a use case:

1. Retrieve a Case from the storage. The case has two Involved objects.
2. Remove the to Involved objects, and add a new one.

When saving, a new Case object is created (in the web layer) and persisted (in the ejb layer). An update is issued, since the id is set. However, the Case has now 3 Involved objects and not 1. The two old ones are not removed.

Another use case:
1. Retrieve a Case from the storage. The case has two Involved objects.
2. Change one of the Involved.

This result in the following error from the JDBCExceptionReporter:
[IBM][CLI Driver][DB2/NT] SQL0803N One or more values in the INSERT statement, UPDATE statement, or foreign key update caused by a DELETE statement are not valid because the primary key, unique constraint or unique index identified by "1" constrains table "INVOLVED" from having duplicate rows for those columns. SQLSTATE=23505

Here's my mappings (only the important parts):

Code:

<hibernate-mapping auto-import="false">
 <class name="Case" table="CASE">
  <id name="id" type="long" column="ID">
   <generator class="identity"/>
  </id>
  <set name="involved" table="INVOLVED" inverse="true" cascade="all-delete-orphan">
   <key column="CASEID"/>
   <one-to-many class="Involved"/>
  </set>        
 </class>
</hibernate-mapping>

<hibernate-mapping auto-import="false">
 <class name="Involved" table="INVOLVED">
  <composite-id unsaved-value="any">
   <key-property name="id"/>
   <key-many-to-one name="sak" column="CASEID"/>
  </composite-id>       
 </class>
</hibernate-mapping>

The database is set up like this:

Code:

CREATE TABLE CASE
(ID INTEGER GENERATED BY DEFAULT AS IDENTITY (START WITH 1, INCREMENT BY 1, NO CACHE ) NOT NULL,
   [...]
);

ALTER TABLE CASE
ADD CONSTRAINT id PRIMARY KEY (ID);

CREATE TABLE INVOLVED
(ID VARCHAR(11) NOT NULL,
   CASEID INTEGER NOT NULL,
   [...]
);

ALTER TABLE INVOLVED
ADD CONSTRAINT id_caseId PRIMARY KEY (ID, SAKID);
  
ALTER TABLE INVOLVED
ADD CONSTRAINT INVOLVERT_CASE FOREIGN KEY (CASEID)
REFERENCES CASE(ID);

Is it possible to change a collection (both the number of members, and the attributes of a member). Outside the session which retrieved the holding component? When I do it inside the same session, everything seems fine.

Hope you can help me out.

Regards,
Ola

olas · **Joined:** Tue Dec 16, 2003 9:57 am **Posts:** 13

Additional information:

I've overridden the equals() and hashMap() methods in the Involved class. To objects are equal if id and caseid of the two are the samen.

- Ola

olas · **Joined:** Tue Dec 16, 2003 9:57 am **Posts:** 13

Note to self:

the following thread seems to be the same issue:

http://forum.hibernate.org/viewtopic.php?t=926960

michael · **Posted:** Sun Jan 18, 2004 9:19 am

Quote:

Is it possible to change a collection (both the number of members, and the attributes of a member).

1. Yes. But all-delete-orphan works only when the elements are removed within the session. So you have to delete removed elements manually somehow.

2. Yes. Most likely your unsaved-value mapping is wrong, resutling in a call to INSERT instead of UPDATE.

emmanuel · **Posted:** Mon Jan 19, 2004 2:37 am

gloeglm wrote:

1. Yes. But all-delete-orphan works only when the elements are removed within the session. So you have to delete removed elements manually somehow.

Not sure of that, but for sure, the underlying collection must be the SAME : Hibernate flag the deletion undercover thanks to it's own implementation.
As Michael said object.setList(someOtherList) won't work.

michael · **Posted:** Mon Jan 19, 2004 4:25 am

Hmm, I thought I had read this somewhere in the manual, can't find it now however. I will try this sometimes today and try to confirm.

olas · **Joined:** Tue Dec 16, 2003 9:57 am **Posts:** 13

Hi again,
I'm trying to implement the Interceptor pattern - but have run into troubles as explained in this thread:

http://forum.hibernate.org/viewtopic.php?t=927190

- Ola