Unique Key Violation While Doing Multiple Updates And Create in EJB

Question

Hello All,
I am using oracle 9i and Weblogic 7.0. I have a table that has a unique key constraint on one column , say 'Col1' and i am using a CMP to read,create and update data in this table. The problem description is as follows.
I have JTable that display the data from the above said table. The user can modify the existing data and insert new data that will be reflected in the DB using the CMP. Let us say the following are displayed
ROW1
Col1 : 3
Col2 : 'ABC'
Col3 : 1 (Primary key in the table)
Now the user modifies the above row and inserts a new record. Now the following will be the display
ROW1 (Modified)
Col1 : 4
Col2 : 'ABC'
Col3 : 1 (Primary key in the table)
ROW2 (New)
Col1 : 3
Col2 : 'DEF'
Col3 : 2 (Primary key in the table)
When the above data is saved i do the following in the Code
a) Session Bean
For (all the data in the Jtable)
try
home.findByPrimaryKey(Col3);
remote.update(Col1,Col2);
catch(FinderException fe)
home.create(Col1,Col2,Col3);
When the above code is run During the first loop the update runs succesfully (i.e update old value of 3 with 4 ) but during the 2nd loop the create (i.e Insert new value 3) gives me the unique key violated exception. The following is the stack trace
<Oct 25, 2004 11:36:22 AM IST> <Info> <EJB> <010049> <EJB Exception in method: ejbPostCreate: java.sql.SQLException: ORA-00001: unique constraint (UAT_CYCLE2_1.UK_PYMT_DET_TX) violated
java.sql.SQLException: ORA-00001: unique constraint (UAT_CYCLE2_1.UK_PYMT_DET_TX) violated
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:289)
at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:579)
at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1892)
at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteFetch(TTC7Protocol.java:1093)
at oracle.jdbc.driver.OracleStatement.executeNonQuery(OracleStatement.java:2130)
at oracle.jdbc.driver.OracleStatement.doExecuteOther(OracleStatement.java:2013)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2869)
at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:608)
at weblogic.jdbc.jts.Statement.executeUpdate(Statement.java:509)
at de.dl.ucs.contract.entity.TerminalPaymentsCMP_kbdoop__WebLogic_CMP_RDBMS.__WL_create(TerminalPaymentsCMP_kbdoop__WebLogic_CMP_RDBMS.java:1435)
at de.dl.ucs.contract.entity.TerminalPaymentsCMP_kbdoop__WebLogic_CMP_RDBMS.ejbPostCreate(TerminalPaymentsCMP_kbdoop__WebLogic_CMP_RDBMS.java:1353)
at java.lang.reflect.Method.invoke(Native Method)
at weblogic.ejb20.manager.DBManager.create(DBManager.java:1023)
at weblogic.ejb20.manager.DBManager.localCreate(DBManager.java:904)
at weblogic.ejb20.internal.EntityEJBLocalHome.create(EntityEJBLocalHome.java:180)
at de.dl.ucs.contract.entity.TerminalPaymentsCMP_kbdoop_LocalHomeImpl.create(TerminalPaymentsCMP_kbdoop_LocalHomeImpl.java:73)
at de.dl.ucs.contract.helperclasses.SubsegmentMaintanence.saveTerminalPayments(SubsegmentMaintanence.java:697)
at de.dl.ucs.contract.controller.SubsegmentSL.saveSubsegmentDetails(SubsegmentSL.java:570)
at de.dl.ucs.contract.controller.SubsegmentSL.processFinanceSubsegmentSave(SubsegmentSL.java:1601)
at de.dl.ucs.contract.controller.SubsegmentSL_kgzv4j_EOImpl.processFinanceSubsegmentSave(SubsegmentSL_kgzv4j_EOImpl.java:498)
at de.dl.ucs.contract.events.FinanceSubsegmentBEH.saveSubsegmentDetails(FinanceSubsegmentBEH.java:749)
at de.dl.ucs.contract.events.FinanceSubsegmentBEH.processEvent(FinanceSubsegmentBEH.java:232)
at de.dl.ucs.framework.flowcontroller.ControllerBean.delegateAction(ControllerBean.java:229)
at de.dl.ucs.framework.flowcontroller.ControllerBean_riqvk4_EOImpl.delegateAction(ControllerBean_riqvk4_EOImpl.java:46)
at de.dl.ucs.framework.flowcontroller.ControllerBean_riqvk4_EOImpl_WLSkel.invoke(Unknown Source)
at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:441)
at weblogic.rmi.cluster.ReplicaAwareServerRef.invoke(ReplicaAwareServerRef.java:114)
at weblogic.rmi.internal.BasicServerRef$1.run(BasicServerRef.java:382)
at weblogic.security.service.SecurityServiceManager.runAs(SecurityServiceManager.java:726)
at weblogic.rmi.internal.BasicServerRef.handleRequest(BasicServerRef.java:377)
at weblogic.rmi.internal.BasicExecuteRequest.execute(BasicExecuteRequest.java:30)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:234)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:210)
>
<Oct 25, 2004 11:36:22 AM IST> <Info> <EJB> <010051> <EJB Exception during invocation from home: [email protected] threw exception: javax.ejb.TransactionRolledbackLocalException: EJB Exception:; nested exception is: java.sql.SQLException: ORA-00001: unique constraint (UAT_CYCLE2_1.UK_PYMT_DET_TX) violated
Please help me with this, as far as i am concerned since both update and create is in the same transaction the update on the row must be visible to the create and hence there shouild not be any problem.....
thanks in advance
Shanki

Answer 1

Hi,
Thanks,
There are 3 columns involved with that table . Out of whihc one is a Primary Key (string) , The other column (Number) has a unique key constraint defined on it and the last column stores a value corresponding to the 2nd column.
The reason for me to do a create in the Finder exception is as follows.
I Loop through the Data present in JTable. As given in the example let us assume that there are 2 rows in the JTable. Out of whihc the First row needs an updation and the second row , which is a new row needs to be created. So During the First iteration of the loop, The findermethod does not throw any exception (Because it is a modfied row) and hence the update gets fired successfully. During the second iteration , since it is a new row the findermethod will throw a finder exception and hence create will get fired.
I understand that this is not a good coding style but then it is not 100% wrong and i need to find out as to why it is not working.
Hope am clear in explaining my problem
Thanks
Shanki