Regarding CMP entity bean

in ejb-jar.xml when i add select method "CMP select methods" it get added into CMP entity bean.
I have added lookup method than got the refrence of LocalHomeInterface in the servlet
Now my confusion is how to use this method to get the returbed value from that added select method.
Please guide me.
regards
gaurav

Hi Young,
From the information you have supplied, my guess is that the SQL
string that OC4J is sending to SQL-Server is incorrect. So it may
help if you could see the exact SQL string. In order to see the
SQL string, I suggest you either run OC4J in "debug" mode, or try
using "P6 Spy".
The following web page has details on running OC4J in "debug" mode:
http://kb.atlassian.com/content/atlassian/howto/orionproperties.jsp
And here is the web page for "P6 Spy"
http://www.provision6.com/
And these other web sites may also be of help (in general):
http://www.orionserver.com
http://www.orionsupport.com
http://www.atlassian.com
http://www.elephantwalker.com
Good Luck,
Avi.

Similar Messages

CMP Entity Bean's problem with MS-SQL Server 2000

Hi everyone!
I have a problem regarding CMP Entity Bean on OC4J.
I made one CMP Entity Bean and deployed it to OC4J.
It was successful.
I used MS-SQL Server 2000 as Datasource.
So, I installed MS-SQL Server's JDBC Driver and add some jar files to classpath.
And I updated 'data-sources.xml' in OC4J's config directory.
Then, I updated also 'orion-ejb-jar.xml' in my application's directory.
I changed data-source's name to my data-source's name which use MS-SQL Server 2000.
Finally, I started OC4J and EJB Client program which called Enitiy Bean's create method.
But, The error occured which was 'Database error: java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]LINE 1: '.' Wrong sentence'.
What's wrong? I need any helps.
Here is stack overflow message. Thank you. Best regards.
com.evermind.server.rmi.OrionRemoteException: Transaction was rolled back: Database error: java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC][SQLServer]LINE 1: '.' Wrong sentence.
     at UserHome_EntityHomeWrapper2.create(UserHome_EntityHomeWrapper2.java:1114)
     at java.lang.reflect.Method.invoke(Native Method)
     at com.evermind.server.rmi.RMICallHandler.run(RMICallHandler.java:80)
     at com.evermind.util.ThreadPoolThread.run(ThreadPoolThread.java:64)
at connection to localhost/127.0.0.1 as admin
     at com.evermind.server.rmi.RMIConnection.EXCEPTION_ORIGINATES_FROM_THE_REMOTE_SERVER(RMIConnection.java:1530)
     at com.evermind.server.rmi.RMIConnection.invokeMethod(RMIConnection.java:1453)
     at com.evermind.server.rmi.RemoteInvocationHandler.invoke(RemoteInvocationHandler.java:53)
     at com.evermind.server.rmi.RecoverableRemoteInvocationHandler.invoke(RecoverableRemoteInvocationHandler.java:22)
     at __Proxy0.create(Unknown Source)
     at com.emc.ksc.ejb.user.UserBeanTestClient1.create(UserBeanTestClient1.java:73)
     at com.emc.ksc.ejb.user.UserBeanTestClient1.<init>(UserBeanTestClient1.java:49)
     at com.emc.ksc.ejb.user.UserBeanTestClient1.main(UserBeanTestClient1.java:1077)

Hi Young,
From the information you have supplied, my guess is that the SQL
string that OC4J is sending to SQL-Server is incorrect. So it may
help if you could see the exact SQL string. In order to see the
SQL string, I suggest you either run OC4J in "debug" mode, or try
using "P6 Spy".
The following web page has details on running OC4J in "debug" mode:
http://kb.atlassian.com/content/atlassian/howto/orionproperties.jsp
And here is the web page for "P6 Spy"
http://www.provision6.com/
And these other web sites may also be of help (in general):
http://www.orionserver.com
http://www.orionsupport.com
http://www.atlassian.com
http://www.elephantwalker.com
Good Luck,
Avi.

Error While Deploying A CMP Entity Bean With A Composite Primary Key

Hello all,
I have a problem deploying CMP Entity beans with composite primary keys. I have a CMP Entity Bean, which contains a composite primary key composed of two local stubs. If you know more about this please respond to my post on the EJB forum (subject: CMP Bean Local Stub as a Field of a Primary Key Class).
In the mean time, can you please tell me what following error message means and how to resolve it? From what I understand it might be a problem with Sun ONE AS 7, but I would like to make sure it's not me doing something wrong.
[05/Jan/2005:12:49:03] WARNING ( 1896):      Validation error in bean CustomerSubscription: The type of non-static field customer of the key class
test.subscription.CustomerSubscriptionCMP_1530383317_JDOState$Oid must be primitive or must implement java.io.Serializable.
     Update the type of the key class field.
     Warning: All primary key columns in primary table CustomerSubscription of the bean corresponding to the generated class test.subscription.CustomerSubscriptionCMP_1530383317_JDOState must be mapped to key fields.
     Map the following primary key columns to key fields: CustomerSubscription.CustomerEmail,CustomerSubscription.SubscriptionType. If you already have fields mapped to these columns, verify that they are key fields.Is it enough that a primary key class be serializable or all fields have to implement Serializable or be a primitive?
Please let me know if you need more information to answer my question.
Thanks.
Nikola

Hi Nikola,
There are several problems with your CMP bean.
1. Fields of a Primary Key Class must be a subset of CMP fields, so yes, they must be either a primitive or a Serializable type.
2. Sun Application Server does not support Primary Key fields of an arbitrary Serializable type (i.e. those that will be stored
as BLOB in the database), but only primitives, Java wrappers, String, and Date/Time types.
Do you try to use stubs instead of relationships or for some other reason?
If it's the former - look at the CMR fields.
If it's the latter, I suggest to store these fields as regular CMP fields and use some other value as the PK. If you prefer that
the CMP container generates the PK values, use the Unknown
PrimaryKey feature.
Regards,
-marina

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

Exception in calling a CMP Entity Bean

I have deployed a simple CMP entity bean using jboss App. server, Now while executing the client i got the following exception,
error in clientjavax.naming.CommunicationException [Root exception is java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: org.jnp.interfaces.FastNamingProperties (no security manager: RMI class loader disabled)]
regards,
NaveenBabu.A

Hi,
It is likely that some libraries are missing in your client environment. (it has nothing to do with security)
Make sure that the libraries in JBoss client (folder your_jboss_folder/client) are in your client application classpath. In particular, look for jnp-client.jar.
This should solve the problem.
Bruno Collet
http://www.practicalsoftwarearchitect.com

Bad Performance/OutOfMemory Error in CMP Entity Bean with Large DB

Hello:
I have an CMP Entity deployed on WLS 7.0
The entity bean maps to a table that has 97,480 records.
It has a finder: findAll() -- SELECT OBJECT(e) FROM Equipment e
I have a JSP client that invokes the findALL()
The performance is very poor ~ 150 seconds just to perform the findAll() - (Benchmark
from within the JSP code)
If more than one simultaneous call is made then I get outOfMemory Error.
WLS is started with max memory of 512MB
EJB is deployed with <max-beans-in-cache>100000</max-beans-in-cache>
(without max-beans-in-cache directive the performance is worse)
Is there any documentation available to help us in deploying CMP Entity Beans
with very large number of records (instances) ?
Any help is greatly appreciated.
Regards
Rajan

Hi
You should use a Select Method, it does support cursors.
Or a Home Select Method combination.
Regards
Thomas
WLS is started with max memory of 512MB
EJB is deployed with <max-beans-in-cache>100000</max-beans-in-cache>>
(without max-beans-in-cache directive the performance is worse)>
Is there any documentation available to help us in deploying CMP
Entity Beans with very large number of records (instances) ? Any help
is greatly appreciated.>
Regards>
Rajan>
>
"Rajan Jena" <[email protected]> schrieb im Newsbeitrag
news:3dadd7d1$[email protected]..
>
Hello:
I have an CMP Entity deployed on WLS 7.0
The entity bean maps to a table that has 97,480 records.
It has a finder: findAll() -- SELECT OBJECT(e) FROM Equipment e
I have a JSP client that invokes the findALL()
The performance is very poor ~ 150 seconds just to perform the findAll() -(Benchmark
from within the JSP code)
If more than one simultaneous call is made then I get outOfMemory Error.
WLS is started with max memory of 512MB
EJB is deployed with <max-beans-in-cache>100000</max-beans-in-cache>
(without max-beans-in-cache directive the performance is worse)
Is there any documentation available to help us in deploying CMP EntityBeans
with very large number of records (instances) ?
Any help is greatly appreciated.
Regards
Rajan

Catching SQLException in CMP Entity Bean

I wana catch an SQLException which is raised while updating a record in DB through a CMP Entity bean method (violating a Foriegn key constraint). It throws to the client a RemoteException which contains a RollbackException which further contains an EJBException and finally it contains the required SQLException. The containment of exceptions is like RemoteException contains RollbackException contains EJBException contains SQLException.
I know I can parse out the SQLException, but what if I wana know that which foriegn key constraint raised this excepton while updation.
I'm naive in EJB's and I hope the forum will not turn down my trivial question.
Regards
Rana

For example I have a table "Emplyee" having a field key "DeptID", "DeptID" is a foriegn key from table Department.
I have a user interface which can update "Employee" table and another user interface for updating "Departments" table. I can try to update employee A's "DeptID" to 3 whereas somebody else has deleted "DeptID" 3 from the "Department" table, this results in a foriegn key constraint violation at DB level. Now I wana catch this exception and report it to the client that the updation was not successful. How I can catch this exception.
The current situation is that the container throws a RemoteException. This RemoteException contains the following nested hierarchy of exceptions
RollbackException>> EJBException>> SQLException.
At client side I'm not sure which exception caused the RemoteException until and unless I can find the Deepest exception (SQLException in this case) in the nested hierarchy.
How I can write the code for handling exception as RemoteException from the container can be in the result of many other Exceptions as well.
Regards
Rana

Problem in creating CMP Entity Bean - Pls Help

I am trying to build one simple project having jsps to get connected to CMP Entity Bean.
But while deploying I am getting the following error...
Nov 15, 2004 10:59:09... Info: End of log messages of the target system.
Nov 15, 2004 10:59:09... Info: ***** End of SAP J2EE Engine Deployment (J2EE Application) *****
Nov 15, 2004 10:59:09... Error: Execution of deployment action for "EntityCMPAppln" aborted:
Caught exception during application deployment from SAP J2EE Engine's deploy service:
java.rmi.RemoteException: Error occurred while starting application bcone.com/EntityCMPAppln and wait.
Reason: Complex error : server ID 6155350:Application bcone.com/EntityCMPAppln cannot be started, because it has hard reference to resource CONFIG_DB with type javax.sql.DataSource, but it is not active on the server.
(message ID: com.sap.sdm.serverext.servertype.inqmy.extern.EngineApplOnlineDeployerImpl.performAction(DeploymentActionTypes).REMEXC)
Nov 15, 2004 10:59:09... Error: Deployment NOT successful for EntityCMPAppln
Nov 15, 2004 10:59:09... Info: SDM configuration: Do not automatically start/stop J2EE Engine. Do not restore state of J2EE Engine now.
Nov 15, 2004 10:59:09... Error: -
At least one of the Deployments failed -
Nov 15, 2004 11:05:16... Info: Request for Logon as admin accepted
===========================================
Nov 15, 2004 11:05:08... Info: =   Starting to execute command 'remotegui'   =
Nov 15, 2004 11:05:08... Info: ===============================================
Nov 15, 2004 11:05:10... Info: SDM started successfully.
Please tell me how to activate the CONFIG_DB reference in database. Or what Extra I have to do to run this example.
Regards,
Vivek Ojha

Dear Benny,
The code of the required files is pasted below....
Application.XML
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application PUBLIC "-//Sun Microsystems, Inc.//DTD J2EE Application 1.3//EN"
                             "http://java.sun.com/dtd/application_1_3.dtd">
<application>
    <display-name>EntityCMPAppln</display-name>
    <description>EAR description</description>
    <module>
        <ejb>EntityCMPEjb.jar</ejb>
    </module>
    <module>
        <web>
            <web-uri>EntityCMPWeb.war</web-uri>
            <context-root>/student</context-root>
        </web>
    </module>
</application>
Application-j2ee-engine.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application-j2ee-engine SYSTEM "application-j2ee-engine.dtd">
<application-j2ee-engine>
     <provider-name>bcone.com</provider-name>
     <fail-over-enable
          mode="disable"/>
</application-j2ee-engine>
data-source-aliases.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE data-source-aliases SYSTEM "data-source-aliases.dtd">
<data-source-aliases>
     <aliases>
          <data-source-name>${com.sap.datasource.default}</data-source-name>
          <alias>STUDENTDB</alias>
     </aliases>
</data-source-aliases>
ejb-j2ee-engine.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-j2ee-engine SYSTEM "ejb-j2ee-engine.dtd">
<ejb-j2ee-engine>
     <enterprise-beans>
          <enterprise-bean>
               <ejb-name>StudentBean</ejb-name>
               <resource-ref>
                    <res-ref-name>jdbc/STUDENTDB</res-ref-name>
                    <res-link>STUDENTDB</res-link>
               </resource-ref>
               <entity-props/>
          </enterprise-bean>
     </enterprise-beans>
</ejb-j2ee-engine>
ejb-jar.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN" "http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar>
     <description>EJB JAR description</description>
     <display-name>EJB JAR</display-name>
     <enterprise-beans>
          <entity>
               <ejb-name>StudentBean</ejb-name>
               <home>com.bcone.ejb.StudentHome</home>
               <remote>com.bcone.ejb.Student</remote>
               <ejb-class>com.bcone.ejb.StudentBean</ejb-class>
               <persistence-type>Container</persistence-type>
               <prim-key-class>java.lang.String</prim-key-class>
               <reentrant>False</reentrant>
               <cmp-version>2.x</cmp-version>
               <abstract-schema-name>StudentBean</abstract-schema-name>
               <cmp-field>
                    <field-name>studentId</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>lname</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>standard</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>fyear</field-name>
               </cmp-field>
               <cmp-field>
                    <field-name>fname</field-name>
               </cmp-field>
               <primkey-field>studentId</primkey-field>
               <resource-ref>
                    <res-ref-name>jdbc/STUDENTDB</res-ref-name>
                    <res-type>javax.sql.DataSource</res-type>
                    <res-auth>Container</res-auth>
               </resource-ref>
          </entity>
     </enterprise-beans>
</ejb-jar>
persistent.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE persistent-ejb-map SYSTEM "persistent.dtd">
<persistent-ejb-map>
     <locking
          type="Table"/>
     <db-properties>
          <data-source-name>CONFIG_DB</data-source-name>
          <database-vendor
               name="SAPDB"/>
     </db-properties>
     <entity-beans>
          <entity-bean>
               <ejb-name>StudentBean</ejb-name>
               <table-name>TMP_STUDENTNEW</table-name>
               <field-map
                    key-type="PrimaryKey">
                    <field-name>studentId</field-name>
                    <column>
                         <column-name>STUDENTID</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>lname</field-name>
                    <column>
                         <column-name>LNAME</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>standard</field-name>
                    <column>
                         <column-name>STANDARD</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>fyear</field-name>
                    <column>
                         <column-name>FYEAR</column-name>
                    </column>
               </field-map>
               <field-map
                    key-type="NoKey">
                    <field-name>fname</field-name>
                    <column>
                         <column-name>FNAME</column-name>
                    </column>
               </field-map>
          </entity-bean>
     </entity-beans>
     <relationships/>
</persistent-ejb-map>
StudentBean.java
package com.bcone.ejb;
import javax.ejb.EntityBean;
import javax.ejb.EntityContext;
import javax.ejb.RemoveException;
import javax.ejb.CreateException;
@abstractSchemaName StudentBean
@cmpVersion 2.x
@ejbHome <{com.bcone.ejb.StudentHome}>
@ejbPrimaryKey <{java.lang.String}>
@ejbRemote <{com.bcone.ejb.Student}>
@hasSimplePK true
public abstract class StudentBean implements EntityBean {
     public void ejbLoad() {
     public void ejbStore() {
     public void ejbRemove() throws RemoveException {
     public void ejbActivate() {
     public void ejbPassivate() {
     public void setEntityContext(EntityContext context) {
          myContext = context;
     public void unsetEntityContext() {
          myContext = null;
     private EntityContext myContext;
@primKeyField
     public abstract String getStudentId();
     public abstract void setStudentId(String studentId);
     public abstract String getLname();
     public abstract void setLname(String lname);
     public abstract String getFname();
     public abstract void setFname(String fname);
     public abstract String getStandard();
     public abstract void setStandard(String standard);
     public abstract String getFyear();
     public abstract void setFyear(String fyear);
Create Method.
     public String ejbCreate(
          String studentId,
          String fname,
          String lname,
          String standard,
          String fyear)
          throws CreateException {
          setStudentId(studentId);
          setFname(fname);
          setLname(lname);
          setStandard(standard);
          setFyear(fyear);
          return null;
Post Create Method.
     public void ejbPostCreate(
          String studentId,
          String fname,
          String lname,
          String standard,
          String fyear) {
          // TODO : Implement
StudentData.java
Created on Nov 14, 2004
To change the template for this generated file go to
Window>Preferences>Java>Code Generation>Code and Comments
package com.bcone.data;
@author Administrator
To change the template for this generated type comment go to
Window>Preferences>Java>Code Generation>Code and Comments
public class StudentData {
     private String studentId;
     private String fname;
     private String lname;
     private String standard;
     private String fyear;
@return
     public String getFname() {
          return fname;
@return
     public String getFyear() {
          return fyear;
@return
     public String getLname() {
          return lname;
@return
     public String getStandard() {
          return standard;
@return
     public String getStudentId() {
          return studentId;
@param string
     public void setFname(String string) {
          fname = string;
@param string
     public void setFyear(String string) {
          fyear = string;
@param string
     public void setLname(String string) {
          lname = string;
@param string
     public void setStandard(String string) {
          standard = string;
@param string
     public void setStudentId(String string) {
          studentId = string;
student.jsp
<%@ page language="java" %>
<html>
     <head>
          <title>
               Title
          </title>
     </head>
     <body>
          <form method="POST" action="WEBBOT-SELF" name="Student" onSubmit="">

<br>
<a href="/student/manageStudent.jsp?action=add" method="post"> Create </a>
<a href="/student/manageStudent.jsp?action=modify" method="post"> Modify </a>
<a href="/student/manageStudent.jsp?action=delete" method="post"> Delete </a>
<br><br>
<table border="1" width="32%">
    <tr>
      <td width="39%">Student ID </td>
      <td width="61%"><input type="text" name="studentId" size="20"></td>
    </tr>
    <tr>
      <td width="39%">First Name</td>
      <td width="61%"><input type="text" name="fname" size="20"></td>
    </tr>
    <tr>
      <td width="39%">Last Name</td>
      <td width="61%"><input type="text" name="lname" size="20"></td>
    </tr>
    <tr>
      <td width="39%">Standard</td>
      <td width="61%"><input type="text" name="standard" size="20"></td>
    </tr>
    <tr>
      <td width="39%">Fiscal Year</td>
      <td width="61%"><input type="text" name="fyear" size="20"></td>
    </tr>
    <tr>
      <td width="39%" align="center"><input type="submit" value="Submit" name="submit"></td>
      <td width="61%" align="center"><input type="reset" value="Reset" name="reset"></td>
    </tr>
</table>
</form>
     </body>
</html>
mamageStudent.jsp
<%@ page language="java"
import="javax.naming.,java.sql.,javax.sql,com.bcone.ejb."
%>
<html>
     <head>
          <title>
               Manage Student
          </title>
     </head>
     <body>
          <h1>
          </h1>
<jsp:useBean id="stu" class="com.bcone.data.StudentData" ></jsp:useBean>
<jsp:setProperty name="stu" property="*" />
<%
try {
     InitialContext ctx = new InitialContext();
     StudentHome home = (StudentHome) ctx.lookup("java:comp/env/StudentBean");
     String str = request.getParameter("action");
     if("action".equals(str)) {
          Student rem = home.create(remote.setFname(stu.getStudentId(),stu.getFname(),stu.getLname(),stu.getStandard(),stu.getFyear());
          out.println(stu.getStudentId() + "Student Created");
     } else if ("modify".equals(str)) {
          Student remote = home.findByPrimaryKey(stu.getStudentId());
          remote.setFname(stu.getFname());
          remote.setFname(stu.getLname());
          remote.setFname(stu.getStandard());
          remote.setFname(stu.getFyear());
          out.println(stu.getStudentId() + "Student modified");
     } else if ("delete".equals(str)) {
          Student stu1 = home.findByPrimaryKey(stu.getStudentId());
          stu1.remove();
          out.println(stu.getStudentId() + "Student deleted");
} catch (Exception e) {
     out.println("Exception e"+e.toString());
%>
     </body>
</html>
Regards,
Vivek Ojha

CMP Entity Beans read database row twice?

Here are two basic questions regarding container managed persistence Entity Beans:
How many database read operations are performed when a remote reference to a CMP Entity Bean is obtained by a client?
Is it correct, that each row is read twice?
For example if a have one row in a database which I want to lookup, AFAIK first the findByPrimaryKey method perfoms a select to lookup the primary key, and then the (container-)ejbLoad method actually reads the row a second time to populate the CMP fields of the bean.
And how often are UPDATE statements performed?
Is a database UPDATE statement performed each time a setXX method is invoked?
Thanks for any help,
Robert

How many database read operations are performed when a
remote reference to a CMP Entity Bean is obtained by a
client?
Is it correct, that each row is read twice?It all depends on the CMP system. A simple system might well hit the database twice, once to validate the primary key and once to load the object's fields. A
smarter system might try to cache the results from the first, so it didn't need to do the second (although this might be a bit dodgy from a transactional point of view).
However, a couple of facts about databases come in here. Firstly, the query to check the primary key doesn't actually need to load any data from the table: it just needs to check that the key exists. Thus, it should be possible to handle this query just using the index, not touching the table itself at all. Secondly, databases do their own caching, so if a row was loaded in the first query, there is a good chance that it would still be around for the second.
And how often are UPDATE statements performed?
Is a database UPDATE statement performed each time a
setXX method is invoked?Under CMP 1.1, UPDATES are typically done at the end of a transaction; if you use container-demarcated transactions, then yes, UPDATES will happen after every call. If the client code sets up its own transaction, then the UPDATE will only happen after several setXXX calls.
This can be a performance problem. A common solution is the use of coarse-grained detail objects:
http://java.sun.com/j2ee/blueprints/sample_application/model/ (section 10.4.1.2)

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

Re: Using CMP Entity Beans in Business Logic

One thing that you need to answer here is
"In the queries for the subsequent tables, in the where clause will the fields be the same and is it that only their values change?"
In the above is true I'd suggest going for a CMP as you save a lot of coding and transaction management out there.
If the above is not true and even the fields in the where clause change on fly there is no way that you can go for CMP. You will have to go for BMP.
Hope this helps decide

Hi.
You might try posting this message to the weblogic.developer.interest.cmp
newsgroup.
Regards,
Michael
Pankaj wrote:
Hi,
I have made a few CMP entity beans which are mapped to single tables in
Oracle 8i.
Create and remove of a row is working fine via the entity bean.
But when i try to update a particular row it is not happening.
The steps that I am doing are :
1. call home.findByPrimaryKey(instance of the Primary key class)
2. remote.setXXX for the field to be modified.
when i invoke setXXX() method the methods are called in the following
sequence : ejbLoad() > setXXX() > ejbStore()
but the data is not getting persisted in the Data base ....in the column it
is still the same old data.
is it something to do with a commit call or some configuration issue??....
Is there any other step to be called
I am using Weblogic 6.1 Sp2
Any help will be appreciated....This is really urgent...
Thank you,
Pankaj--
Michael Young
Developer Relations Engineer
BEA Support

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>

GetId () returns 0 for CMP Entity Bean

Hi
I'm currently using the HR OE schema that you can download from otn to do some test with EJBs. After creating an CMP Entity Bean, deploying it to the container that comes with JDeveloper9i and accesing it via the Sample Client I get 0 for the id column. All other columns works fine the only one showing a value of 0 is the id column.

I have created a CMP bean and when I use the create method,it inserts 0 in the primary key filed.This only happens if I do not supply a value for that field in the method.So try to check the create method and make sure that the primary key argument is there.In other words,oracle container inserts 0 in the primary key filed if no argument is supplied.
Regards,
Madani

Do I must include orion-ejb-jar.xml in my CMP entity bean?

Deal all:
I've had a problem about deployment of my CMP entity bean.
I don't know if I need to include orion-ejb-jar.xml in the jar
file? Could anyone tell me what files I should include them in
jar file and what config file(like data-sources.xml) I should
modify them?
Thanks!!

The orion-ejb-jar.xml is not necessary...oc4j/orion auto-
generates this configuration file when the application is
deployed. You would only need this file if you are using o-r
mapping, or changing some deployment time option with your ejb.
The config/data-sources.xml file is used by the container. If
you are using oracle, you will need to use the data-sources.xml
for your database (the path needs the proper database name, and
server host, and you will need to put in the password and
username). Use the example with the oc4j docs to help you, or
the one already in your config directory.
regards,
the elephantwalker
www.elephantwalker.com

How to use same transaction when calling CMP entity beans and DAO (JDBC)

We are currently using Weblogic 8.1 SP2 with an Oracle 10g database (using XA thin and non-XA drivers).
We have a session bean that invokes an entity bean and a DAO (data access object pattern) in order to add data in 2 separate tables (account and history). Rows are added to the first (account) table using a CMP Entity bean while inserts are done in the 2nd (history) table using a DAO. Here is some pseudo code:
addHistorySessionBean (trans-attribute="Required")
begin
Step #1 - call addAccountEntityBean (trans- attribute="Required")
Step #2 - call addHistoryDAO (get datasource, connection)
end
The 2nd table (history) has a foreign key constraint to ensure that the corresponding key exists in the first (account) table. Unfortunately, DAO inserts on the 2nd (history) table fail with a foreign key constraint violation (INTEGRITY CONSTRAINT VIOLATION - PARENT KEY NOT FOUND!) since they cannot see the row added to the 1st (account) table in step #1 by the CMP entity bean.
How does one ensure that all this is done in a single transaction ? It appears that the app server creates two seperate transactions (one for the session bean facade and the entity bean and a 2nd transaction (when we retrieve a connection using the same data source JNDI name) for the DAO.
A post on server side suggested using a "<resource-ref>" in the session bean to tie the two potentially separate transactions together, but that does not work for us. However, I am not sure if we are doing that correctly. After we define the resource ref in the session facade bean, do we use the resource ref "name" attribute to lookup the datasource or do we still lookup the datasource by JNDI name ? Do we need to define the resource-ref tag in the entity bean also ?
Does Weblogic allow using a single transaction for this type of a scenario ? How does one specify within Weblogic that the same transaction should be utilized by the entity bean and any subsequent DAOs?
People have also suggested that we defer constraint checking until the transaction(s) are committed but that sounds like a work acount without addressing this issue. Would postponing the constraint checking in Oracle cause any additional overhead ?
Any suggestions with specific examples or documentation on how to address this issue will be gratefully appreciated.

Thanks for your suggestion. Unfortunately, this does not work since it appears that there are 2 separate transactions going on here. One, the original one initiated by the session bean and used by the entity bean and the other initiated by the DAO. Any other ideas appreciated.
Hi,
Try setting the delay-database-inserts tag to
ejbCreate in RDBMS descriptor file.
http://bernal/stage/wls/docs81/ejb/DDreference-cmp-jar
.html#1113981
vasanthi ramesh

Regarding CMP entity bean

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