Entity beans containing relationships to itself, Inherited Relationships

The system i'm working on contains the following entities:
Order
OrderItem
BillingOrder (extends the Order Entity and adds Billing-specific functionality mapped
over 2 tables)
BillingOrderItem (extends the OrderItem Entity and adds Billing-Item-specific functionality,
mapped over 2 tables)
If I could ask two questions about this scenario:
1) The BillingOrder has a one-to-many relationship with BillingOrderItem. Currently
I have had to define the relationship at this level, what i'd really like to be able
to do is define this relationship at the Order-OrderItem level and have the Billing
entities (plus the other Order-subtypes) inherit this relationship.
2) The BillingOrderItem can form a hierarchy (ie can potentially have parent and
child BillingOrderItems). Is it possible for an entity to be in a relationship with
itself? In this case have a one-to-many relationship between the EntityKey PK of
the BillingOrderItem and the ParentEntityKey CMP field contained within itself.
(Hope that's explained clearly). Just as I type this, in respect to the first point
I made, it would be great to again have this relationship defined at the Order-OrderItem
level and be inherited by various subtypes.
Any help/sample code/pointers would be greatly appreciated.
Thanks in advance.

jtahlborn wrote:
i'm pretty sure we encountered problems trying to have the entity classes in a different jar from the persistence.xml. i think you need to have that stuff all packaged up together in order to get it to work. one common project is probably the way to go.Good point. Persistence unit A is certainly not going to know about the entities mapped in persistence unit B, so the mappings can't work. And unfortunately JBoss does not have facilities to share resources (only classpath elements if you turn off classpath isolation).
You'd still be able to do a distributed design, but you'd need one common EJB that manages the model so you have all entities in one persistence unit. I'd say a DAO EJB layer would be justified in such a design scheme. So you'd have your services in your EJBs which will invoke DAO ejbs in your model-ejb to do the low level transactions.

Similar Messages

EJB 3.0 question - saving an entity bean containing another entity bean

Hi,
First, I want to store an entity bean. Secondly, I want to store another entity bean - containing the first entity bean.
I have the following code in a session bean for this:
public void saveFeedScheduling(FeedScheduling feedScheduling, FeedSource feedSource) {
FeedSource feeds = em.merge(feedSource);
em.flush();
feedScheduling.setFeedSource(feeds);
FeedScheduling feedSched = em.merge(feedScheduling);
em.flush();
This seems to work fine - still, is this the proper way to do it?

Hello,
This kind of parameter can be specified using the relationship annotation.
I'm not 100% sure, but, lok at the "cascade element".
Regards,
Sebastien Degardin

Container Managed Persistence entity bean relationship fields

I want to ask something that until now still confuse. Did Relationship fields in Container Managed Persistence entity beans declare , inside Database table or only Persistence fields .
If Relationship fields not declare inside database table ,how if SQL calls the relationship fields between related entity bean.
did container handle this task.
example: I have 2 entity bean with CMP(Container Managed Persistence)version 2.0
call Player and Team. every entity bean have own relationship fields and persistence fields.
player has playerId(primary key),name,position,age persistence fields and teams is relationship fields.
team has teamId(primary key),name,city and players is relationship fields.
I know that all persistence fields is declare in own database table but how about relationship fields.
can you tellme, How SQL calls can access relationship fields if relatiosnship fields is not declare in database table.
I use J2EE RI SDK version 1.3
and deploytool .
thank's .

thank's for your reply .Now I have another problem
I use J2EE RI from java.sun .I try to follow example in j2eetutorial about CMP Example call RosterApp.ear .
I dont'change anything code inside RosterApp.ear but when I deploy and runclient command thereis syntax error :
java.rmi.ServerException: Remote exception occured in server thread :nested exception is java.rmi.ServerException :exception thrown from bean :nested exception is : java.ejb.EJBException :nested exception is :java.sql.SQLException :syntax error or access violation ,message from server: "you have an error in SQL syntax near "
"leagueBeanTable" WHERE "leagueId" = 'L1' at line 1
in example ,RosterApp.ear use Cloudscape database ,but I try to use Mysql database for RosterApp.ear ,is there any different syntax SQL from Cloudscape to Mysql .
if like that ,so I must edit first SQL calls from Cloudscape to MYSQL . I think because relationship fields is for entity beans only ,so how if mysql database want to access foreign key another table because foreign key isn't declare in databse table.
example : I have 3 entity bean call player, team, league .
1. PlayerEJB have persistence fields name, position, playerId(primary key), cmr fields is teams
2. TeamEJB have persistence fields name, city, teamId (primary key) , cmr fields is players and leagues .
3. LeagueEJB have persistence fields name ,sport, leagueId(primary key), cmr fields is teams
so table is
PlayerEJB <--->TeamEJB<--->LeagueEJB
Player have some finder method call findBySport(String Sport) .
because Sport is persistence fields for LeagueEJB
so PlayerEJB must traverse TeamEJB first before LeagueEJB
EJB QL : SELECT distinct object(p) FROM Player (p) IN (p.teams) AS t
WHERE t.league.sport = ?1
I know that Container will translates EJB QL to SQL calls ,but default is only for cloudscape database and I use for MYsql .
so can you helpme how to query method findBySport(String sport) to Mysql calls .
thereis no foreign key between table in database table there is only Relationship fields in entity bean.

Problem with ejb 3.0 entity beans with manyToMany relationship

Hello everyone!
I am using struts 1.2.9 and java ee 5 sdk update 2 for my enterprise application. Besides others i have these entity beans Targetgroup.java and City.java, (i would upload file but i do not know how:)
with manytomany relationship with join table.
when user updates Targetgroup, by clicking on web page with checkboxes and textfields, struts dispatch action calls following method stateless bean:
public void update(String firmId, String targetgroupId, String newGender, String newMinYearsOld, String newMaxYearsOld, String[] newCities) {
TargetgroupPK pkForUpdate = new TargetgroupPK(targetgroupId, firmId);
Targetgroup targetgroupForUpdate = find(pkForUpdate);
targetgroupForUpdate.setGender(newGender);
targetgroupForUpdate.setMinyearold(Integer.parseIn t(newMinYearsOld));
targetgroupForUpdate.setMaxyearold(Integer.parseIn t(newMaxYearsOld));
//pronalazenje gradva za koje je vezana ciljna grupa
Collection<City> newCitiesCollection = new ArrayList<City>();
for(int i = 0; i < newCities.length; i++){
String tmp_city_name = newCities;
City city_obj = cityFacade.find(tmp_city_name);
newCitiesCollection.add(city_obj);
targetgroupForUpdate.setCityidCollection(newCities Collection);
parameter newCities represents names of cities which user checked on his update page. When the page is showen to him some cities are allready check because they were connected with Targetgruoup when it was created (targetgroup).
this code throws following exception:
[#|2007-07-26T12:13:36.993+0200|SEVERE|sun-appserver-pe9.0|javax.enterprise.system.container.web|_Threa dID=16;_ThreadName=httpWorkerThread-8080-0;_RequestID=f79d9c50-86b0-4b6c-96ab-97956dfb39c1;|StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
javax.transaction.RollbackException: Transaction marked for rollback.
at
.com.sun.enterprise.web.connector.grizzly.WorkerTh read.run(WorkerThread.java:75)
javax.ejb.EJBException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaction marked for rollback.
at com.sun.ejb.containers.BaseContainer.completeNewTx (BaseContainer.java:3659)
at com.sun.ejb.containers.BaseContainer.postInvokeTx( BaseContainer.java:3431)
at com.sun.ejb.containers.BaseContainer.postInvoke(Ba seContainer.java:1247)
at com.sun.ejb.containers.EJBLocalObjectInvocationHan dler.invoke(EJBLocalObjectInvocationHandler.java:1 92)
at com.sun.ejb.containers.EJBLocalObjectInvocationHan dlerDelegate.invoke(EJBLocalObjectInvocationHandle rDelegate.java:71)
at $Proxy149.update(Unknown Source)
at audiotel.sms.actions.backoffice.TargetgroupDispatc hAction.updateOrDelete(TargetgroupDispatchAction.j ava:132)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Native MethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(De legatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.struts.actions.DispatchAction.dispatchM ethod(DispatchAction.java:270)
at org.apache.struts.actions.DispatchAction.execute(D ispatchAction.java:187)
at org.apache.struts.action.RequestProcessor.processA ctionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process( RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(Act ionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(Acti onServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
com.sun.enterprise.web.connector.grizzly.WorkerThr ead.run(WorkerThread.java:75)
|#]
exceprion is throwen ONLY when in parameter newCities are city names allready connected to Targetgroup. when NewCities contains names of
City objects which are not connected to Targetgroup it works fine, but it's of no use for me, because user must be able to add or remove certian cities from relaionship with Targetgroup. I think it's because there are rows in join table that contain primary keys of city and targetgroup which are connected so perisistence manager cann't write them again.
i thought it was going to figure it out by itself, and only update those rows.
Does anyone know what is the problem and solution?
Thanks! (forgive my spelling errors :)

solved the problem!
I moved code from sesion bean to struts action as follows:
CityFacadeLocal cityFacade = lookupCityFacade();
//prikupljanje novih podataka o ciljnoj grupi
String newGender = ctf.getGender();
String newMaxYears = ctf.getMaxyears();
String newMinYears = ctf.getMinyears();
String[] newSelectedCities = ctf.getSelectedCities();
//niz imena gradova se prevodi u kolekcju objekata City
Collection<City> newCitiesObjCollection = new Vector<City>();
for(int i = 0; i < newSelectedCities.length; i++){
String tmpCityName = newSelectedCities;
City tmpCityObj = cityFacade.find(tmpCityName);
newCitiesObjCollection.add(tmpCityObj);
//setovanje novih podataka
targetgroupForUD.setGender(newGender);
targetgroupForUD.setMinyearold(Integer.parseInt(newMinYears));
targetgroupForUD.setMaxyearold(Integer.parseInt(newMaxYears));
targetgroupForUD.setCityidCollection(newCitiesObjCollection);
//pozivanje update metdoe u session beany
targetgroupFacade.edit(targetgroupForUD);
//korisnik se vraca na stranu sa svim postojecim ciljnim grupama
forward = mapping.findForward("backend.targetgroups");
and now it works fine. I guess probelm was same transaction scope for Targetgroup and City entities. Now when they are separated it works.
Thanks!

Problem with a 1:M relationship between two entity beans

I am having trouble trying to implement a 1:M relationship between two EJB2.0 entity beans using and EJBQL query. I have an ApplicantEJB, which contains a collection of phone numbers. The applicant table in the database has one primary key, applicant_id. The applicant_phones database table has a compound primary key--applicant_id and phone_type_id--so I have implemented a custom PK class to represent this, PhonePK. I have implemented a findByNameAndPhone method in my ejb-jar.xml file with the following syntax:
SELECT object(a) FROM applicants a, applicant_phones p where a.applicantID = p.applicantID and a.name = ?1 and p.phoneNumber = ?2
If I deploy this, Orion/OC4J translates the query in the orion-ejb-jar.xml with an incorrect reference to the applicant_phones.applicant_id column:
SELECT a.applicant_id FROM applicants a , applicant_phones p WHERE ((a.applicant_id = p.applicantID ) AND (a.name = ?) AND (p.phone_number = ? ))
I must have something wrong with the ApplicantEJB and PhoneEJB primary key mappings in my orion-ejb-jar.xml file, but I have tried many different combinations of values and keep getting them overwritten by the container with each deployment. Why is Orion/OC4J defaulting the applicant_id reference to the ob[i]Long postings are being truncated to ~1 kB at this time.

I have posted excerpts from my orion-ejb-jar.xml file in this posting: Problem mapping a 1:M relationship between two entity EJBs w/ a compound PK
Sorry for the duplicate postings, but I was getting errors on the submission.
April

Relationships in CMP Entity Beans

Hi everyone;
There is a way to implement one-to-many and many-to many relationships in CMP Entity Beans, is there a way to specify a parametrized query or something that do the job on the DBMS?
Regards Francisco.

Container's cascade-deleting in jboss(tm)3.2.x working properly with any scope:
This example with 1 scope:
    <relationships>
        <ejb-relation>
            <ejb-relation-name>Region-Town</ejb-relation-name>
            <ejb-relationship-role>
                <ejb-relationship-role-name>region-has-towns</ejb-relationship-role-name>
                <multiplicity>One</multiplicity>
                <relationship-role-source>
                    <ejb-name>RegionBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>regionTowns</cmr-field-name>
                    <cmr-field-type>java.util.Set</cmr-field-type>
                </cmr-field>
            </ejb-relationship-role>
            <ejb-relationship-role>
                <ejb-relationship-role-name>town-belongs-to-region</ejb-relationship-role-name>
                <multiplicity>Many</multiplicity> <cascade-delete/>
                <relationship-role-source>
                    <ejb-name>TownBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>region</cmr-field-name>
                </cmr-field>
            </ejb-relationship-role>
        </ejb-relation>
    </relationships>

Problem with 1-to-many relationship between entity beans

Hi All!
I have two tables TMP_GROUP and TMP_EMPLOYEE with following fields:
TMP_GROUP: ID, CAPTION, COMMENT, STATUS.
TMP_EMPLOYEE: ID, LOGIN, GROUP_ID.
For this tables i create two entity beans GROUP and EMPLOYEE respectively.
The relationship looks like this
descriptor ejb.xml:
<ejb-relation>
            <description>description</description>
            <ejb-relation-name>employeesOfGroup</ejb-relation-name>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.GroupBean</ejb-relationship-role-name>
                <multiplicity>One</multiplicity>
                <relationship-role-source>
                    <ejb-name>GroupBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>employees</cmr-field-name>
                    <cmr-field-type>java.util.Collection</cmr-field-type>
                </cmr-field>
            </ejb-relationship-role>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.EmployeeBean</ejb-relationship-role-name>
                <multiplicity>Many</multiplicity>
                <relationship-role-source>
                    <ejb-name>EmployeeBean</ejb-name>
                </relationship-role-source>
            </ejb-relationship-role>
        </ejb-relation>
descriptor persistent.xml:
<table-relation>
               <table-relationship-role
                    key-type="PrimaryKey">
                    <ejb-name>GroupBean</ejb-name>
                    <cmr-field>employees</cmr-field>
               </table-relationship-role>
               <table-relationship-role
                    key-type="NoKey">
                    <ejb-name>EmployeeBean</ejb-name>
                    <fk-column>
                         <column-name>GROUP_ID</column-name>
                         <pk-field-name>ejb_pk</pk-field-name>
                    </fk-column>
               </table-relationship-role>
          </table-relation>
Now i implement business method:
public Long addEmployee(String login, long groupId) {
          Long result;
          try {
               EmployeeLocal employee = employeeHome.create(login);
               GroupLocal group =
                    groupHome.findByPrimaryKey(new Long(groupId));
               Collection employees = group.getEmployees();
               employees.add(employee);
               result = (Long) employee.getPrimaryKey();
          } catch (CreateException ex) {
               result = new Long(0);
          } catch (FinderException ex) {
               result = new Long(0);
          return result;
When i call this method from web service, the following exception is raised:
com.sap.engine.services.ejb.exceptions.BaseTransactionRolledbackLocalException: Exception in method com.mypackage.GroupLocalHomeImpl0.findByPrimaryKey(java.lang.Object).
P.S.
1) I have transaction attribute set to "Required" for all methods of all beans
2) I have unique index for each table:
TMP_GROUP_I1: CAPTION
TMP_EMPLOYEE_I1: LOGIN (however i think GROUP_ID must be added here too)
3) I tried many:many relationship with this tables and it works fine
4) I try another implementation of addEmployee method with
EmployeeLocal employee = employeeHome.create(login, groupId);
without using GroupLocal cmr-field and GroupLocalHome findByPrimaryKey method, the result is same error.
Can somebody help me with this problem?
Thanks in advance.
Best regards, Abramov Andrey.

gimbal2 wrote:
1: The @JoinColumn on the listOfDepartments collection in Company is wrong. It should be something like this for a bidirectional relationship:
@OneToMany(mappedBy="company") // company is the matching property name in Department
private List <Department> listOfDepartment = new ArrayList<Department>();Note that I removed the fetch configuration; onetomany is fetched lazy by design. Saves some clutter eh.
2: use a Set in stead of a List (hibernate doesn't like lists much in entities and will break when you create slightly more complex entity relations)
3: don't just slap cascades on collections, especially of type ALL. Do it with care. In the many years I've been using JPA I've only had to cascade deletes in very specific situations, maybe once or twice. I never needed any of the other cascade types, they just invite sloppy code if you ask me. When working with persistence you should apply a little precision.I made all changes as you mentioned but still compID in department table shows null value...

Problem with 1:many relationship between entity beans.

Hi All!
I have two tables TMP_GROUP and TMP_EMPLOYEE with following fields:
TMP_GROUP: ID, CAPTION, COMMENT, STATUS.
TMP_EMPLOYEE: ID, LOGIN, GROUP_ID.
For this tables i create two entity beans GROUP and EMPLOYEE respectively.
The relationship looks like this
descriptor ejb.xml:
<ejb-relation>
            <description>description</description>
            <ejb-relation-name>employeesOfGroup</ejb-relation-name>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.GroupBean</ejb-relationship-role-name>
                <multiplicity>One</multiplicity>
                <relationship-role-source>
                    <ejb-name>GroupBean</ejb-name>
                </relationship-role-source>
                <cmr-field>
                    <cmr-field-name>employees</cmr-field-name>
                    <cmr-field-type>java.util.Collection</cmr-field-type>
                </cmr-field>
            </ejb-relationship-role>
            <ejb-relationship-role>
                <ejb-relationship-role-name>com.mypackage.EmployeeBean</ejb-relationship-role-name>
                <multiplicity>Many</multiplicity>
                <relationship-role-source>
                    <ejb-name>EmployeeBean</ejb-name>
                </relationship-role-source>
            </ejb-relationship-role>
        </ejb-relation>
descriptor persistent.xml:
<table-relation>
               <table-relationship-role
                    key-type="PrimaryKey">
                    <ejb-name>GroupBean</ejb-name>
                    <cmr-field>employees</cmr-field>
               </table-relationship-role>
               <table-relationship-role
                    key-type="NoKey">
                    <ejb-name>EmployeeBean</ejb-name>
                    <fk-column>
                         <column-name>GROUP_ID</column-name>
                         <pk-field-name>ejb_pk</pk-field-name>
                    </fk-column>
               </table-relationship-role>
          </table-relation>
Now i implement business method:
public Long addEmployee(String login, long groupId) {
          Long result;
          try {
               EmployeeLocal employee = employeeHome.create(login);
               GroupLocal group =
                    groupHome.findByPrimaryKey(new Long(groupId));
               Collection employees = group.getEmployees();
               employees.add(employee);
               result = (Long) employee.getPrimaryKey();
          } catch (CreateException ex) {
               result = new Long(0);
          } catch (FinderException ex) {
               result = new Long(0);
          return result;
When i call this method from web service, the following exception is raised:
com.sap.engine.services.ejb.exceptions.BaseTransactionRolledbackLocalException: Exception in method com.mypackage.GroupLocalHomeImpl0.findByPrimaryKey(java.lang.Object).
P.S.
1) I have transaction attribute set to "Required" for all methods of all beans
2) I have unique index for each table:
TMP_GROUP_I1: CAPTION
TMP_EMPLOYEE_I1: LOGIN (however i think GROUP_ID must be added here too)
3) I tried many:many relationship with this tables and it works fine
4) I try another implementation of addEmployee method with
EmployeeLocal employee = employeeHome.create(login, groupId);
without using GroupLocal cmr-field and GroupLocalHome findByPrimaryKey method, the result is same error.
Can somebody help me with this problem?
Thanks in advance.
Best regards, Abramov Andrey.

I have posted excerpts from my orion-ejb-jar.xml file in this posting: Problem mapping a 1:M relationship between two entity EJBs w/ a compound PK
Sorry for the duplicate postings, but I was getting errors on the submission.
April

Composite Primary Key in M:N CMP Entity Bean Relationship

Dear Sir/Madam,
     We are creating an Enterprise Application for our institute using EJB 2.0 specifiactions. In the course of developement, we are facing a problem in writing the CMP Entity Beans with EJB Relationships.
     We are having many to many relationship between two beans such that the primary key of one Entity Bean (let's call it A), serves as the foreign key of another Entity Bean (let's call it B). Further, this primary key of A as foreign key in B, participates in the composite key of B.
     The EJB Specifications require that the primary key field(s) of any bean (B, in our case) declared in the Primary Key class should be the subset of the 'cmp-field' declared in the deployment descriptor for that bean. As I said earlier, we have many to many relationship at play. Hence, we require to keep the foerign key in the 'cmr-field' in lieu of 'cmp-field'. In short, the component of primary key is in 'cmr-field' while, it is needed in both 'cmp-field' and 'cmr-field'. That's perfect from Database point of view but illogical from CMP Entity Bean's view.
     How can we write the deployment descriptor for such a CMP (BMP is working fine for above scenario) Entity Bean? Also, how can we write the Primary Key class? The problem is not just to find the solution, but find under the hood of EJB 2.0 specifications.
     Please help.

I think you should realise that it would not be convenient to use CMP for everything. It is difficult to define complex relations using CMP. Mostly BMP os preferd since it gives the flexibility for the bean developer.
Regards
xH4x0r

Help:How to manage relationships in CMP Entity beans

Hi everybody;
I am using Oracle JDeveloper 9i release 2 and Oracle 9i database.
How can I manage one-to-many and many-to-many relationships in a CMP Entity Bean, I tried to managed the relationships in code, calling the beans, searching for records, making loops and joining.
Is there a better way to manage the relationships with out doing this in code?
Because I think it is not good for performance.
Regards Francisco

public void selectCurriculum(ValueChangeEvent event){
logger.info(event.getNewValue().getClass());
Integer id = (Integer) event.getNewValue();
Collection curriculums = curriculums().getCurriculums();
ObjectCurriculum curriculum = null;
for (Iterator iterator = curriculums.iterator(); iterator.hasNext();) {
ObjectCurriculum objectCurriculum = (ObjectCurriculum) iterator.next();
if(objectCurriculum.getId().equals(id)){
curriculum = objectCurriculum;
break;
curriculum().setWholeObject(curriculum);
logger.info("setting current curriculum");
no message is logged

Tips for Using Containment Relationships (When Are They Required?)

Hello again,
Our team was recently discussing when to use containment relationships, and we realized that there is room for improvement in our understanding. Having read many of the help topics, the primary use for containment relationships seems to be the ability to determine whether or not an entity is complete. However, as far as we can tell, in our work we have not yet encountered a need for the entity-completeness concept (if we have, it was unbeknownst). Instead, using a containment structure within a data model often seems to complicate matters by distancing entities from the Global (thus making it seem more challenging to reason across instances).
My best guess, aside from completeness, is that containment relationships are required when mapping from a database structure (e.g. Siebel). For example, a model such as:
Global
- the invoice
- - the invoice line item
...might interface more correctly with external data structures compared to a "flatter" structure such as:
Global
- the invoice
- the invoice line item
...where a "regular" (non-inferred, non-containment) relationship would be needed to connect invoices to their line items. In the latter scenario, perhaps the relationship would be more difficult to define when the data were mapped over?
I have a feeling we might be missing something obvious, but I'm curious to know what this community thinks about this question. Can anyone help, perhaps by providing a list of advantages / disadvantages to containment, or maybe the situations in which containment is always required?
Thanks!
- Patrick

I've built numerous demo rulebases for integration, usually with Siebel so I'll use that as my example. What I have learnt through doing this is that integration will be easier if the logical structure of the OPA entities/containment relationships matches the logical structure of the Siebel business components.
For example, if in Siebel you have something representing Global (which I'll call a Case for this example), and you also have several business components logically below Case, e.g.
A Case can have multiple Contacts
Each Contact can have multiple Incomes
Each Contact can have multiple Resources
Each Contact can have multiple Expenses
I would set up the following entities/containment relationships in OPA:
Global --> one-to-many --> the household member
the household member --> one-to-many --> the household member's income
the household member --> one-to-many --> the household member's resource
the household member --> one-to-many --> the household member's expense
Note that Contact (Siebel) = the household member (OPA). I could use "the contact" in OPA, but I prefer to use a more business-user friendly name such as "the household member" -- if they are indeed household members, it could also be the person, the taxpayer, etc. or whatever is appropriate for the source material.
I assume this general principle still applies if the integration is with something other than Siebel.
Cheers,
Jasmine

Containment relationship

I have few question around containment relationships:
1. What is the use of containment relationship?
2. Why it is necessary to define containment relationship?
3. Can there be instance of an entity without the containment relationship?
4. In which scenario such a case is possible?
5. As given here an example - http://docs.oracle.com/html/E20340_01/toc.htm
why cant we create a containment relationship between "the child" and "the friend" entity. Why the containment relationship is created from "global" to "the friend" and similarly for "the school" entity , the containment is with the global entity. Also, one child can go to only one school. So the criteria for containment relationship "to-one" is satisfied from "the child" to "the school"
Thanks,
Rajan
Edited by: RP on Aug 26, 2012 3:11 AM
Edited by: RP on Aug 26, 2012 3:17 AM

For question 1
The following topics in Oracle Policy Modeling User's Guide are helpful
"Understand containment relationships and entity completion" where the concept of an entity needing to be complete is determined via the use of containment relationships.
"Reason across multiple entities" where the containment relationship needs to be known to determine the scope of an entity.
"Use multiple properties files on a multi-developer project" where the containtainment relationship used to connect separate property files.
Version 10.4 of OPM automatically creates a default containment relationship.
For question 5 I believe your question is in regards to topic "Define a data model"; your link brings us to the home page.

Finder method in container-managed entity bean

Finder method of a container entity bean is taking the primary key class object of another entity bean. How to map this in the xml descriptor file weblogic-cmp-rdbms.xml for this type of beans.
I am trying to deploy the jasmine computer store of Mastering EJB by EdRoman.
I couldn't write the deployment file weblogic-cmp-rdbms.xml for Order Entity bean which uses CustomerPK as an argument in its finder method.
Please tell me how to write this. I am trying on weblogic 5.1
Thanx in advance
Srivatsa

hello,
in container managed persistence, you specify on your xml file the name of your table. so the primary key you want to use have to be a foreign key in your table. otherwise i don't think that you can use a container managed persistence.
Najib.

Container-managed persistence Entity bean

WE use a container-managed persistence Entity bean. To handle the state synchronization between the object & the database, what must WE do?
Thanks in Advance

That's the container's job. You can use the commit option A/B/C to control how the DB and objects are synchronized.
-Scott
http://www.swiftradius.com

Container Managed Entity Beans and Client Identifier in Oracle

Is it possible to use Container Managed Entity Beans (EJB with CMP)
in a way that the Oracle database sessions still know the
individual Client Identifiers of the actual users
(not just the Identifier of the proxy user defined in the
Connection Pool)?
If Yes: How?
If No: The consequence would be that the
technologies EJB with CMP cannot be user together with
Oracle Virtual Private Databases (VPN) because VPN requires
some kind of Client Identifier.
I am grateful for any hint.
Regards,
Martin Siepmann
+49 (0)163 / 7765328

Not quite an auto-incrementing PK, but it is managed by the container. the following is from the turorial
Generating Primary Key Values
For some entity beans, the value of a primary key has a meaning for the business entity. For example, in an entity bean that represents a phone call to a support center, the primary key might include a time stamp that indicates when the call was received. But for other beans, the key's value is arbitrary--provided that it's unique. With container-managed persistence, these key values can be generated automatically by the EJB container. To take advantage of this feature, an entity bean must meet these requirements:
* In the deployment descriptor, the primary key class is defined as a java.lang.Object. The primary key field is not specified.
* In the home interface, the argument of the findByPrimaryKey method must be a java.lang.Object.
* In the entity bean class, the return type of the ejbCreate method must be a java.lang.Object.
In these entity beans, the primary key values are in an internal field that only the EJB container can access. You cannot associate the primary key with a persistent field or any other instance variable. However, you can fetch the bean's primary key by invoking the getPrimaryKey method, and you can locate the bean by invoking its findByPrimaryKey method.
Maybe that is good enough
christina

Entity beans containing relationships to itself, Inherited Relationships

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