Oracle® TopLink

4.1.1 Incorrect outer join SQL on SQLServer2005

TopLink generates incorrect outer join for SQL Server v2005. The outer join syntax generated is correct for earlier versions of this database. To work around this limitation, reconfigure the database compatibility (refer to the SQLServer documentation for details). Alternatively, you can use a custom TopLink database platform.

4.1.2 UnitOfWork.release() not Supported with External Transaction Control

A unit of work synchronized with a Java Transaction API (JTA) will throw an exception if it is released. If the current transaction requires its changes to not be persisted, the JTA transaction must be rolled back.

When in a container-demarcated transaction, call setRollbackOnly() on the EJB/session context:

@Stateless
public class MySessionBean
{    @Resource 
    SessionContext sc;
    
    public void someMethod()
    {
        ...
        sc.setRollbackOnly();
    }
}

When in a bean-demarcated transaction then you call rollback() on the UserTransaction obtained from the EJB/session context:

@Stateless
@TransactionManagement(TransactionManagementType.BEAN)
public class MySessionBean implements SomeInterface 
{
    @Resource
    SessionContext sc;
    
    public void someMethod() 
    {
        sc.getUserTransaction().begin();
        ...
        sc.getUserTransaction().rollback();
    }
} 

4.1.3 Returning Policy for UPDATE with Optimistic Locking

The returning policy, which allows values modified during INSERT and UPDATE to be returned and populated in cached objects, does not work in conjunction with numeric version optimistic locking for UPDATE. The value returned for all UPDATE operations is 1 and does not provide meaningful locking protection.

Do not use a returning policy for UPDATE in conjunction with numeric optimistic locking.

The use of returning policy for INSERT when using optimistic locking works correctly.

4.1.4 JDBC Drivers returning Timestamps as Strings

TopLink assumes that date and time information returned from the server will use Timestamp. If the JDBC driver returns a String for the current date, TopLink will throw an exception. This is the case when using a DB2 JDBC driver.

To work around this issue, consider using a driver that returns Timestamp (such as COM.ibm.db2.jdbc.app.DB2Driver) or change the policy to use local time instead of server time.

Another option is to use a query re-director on the ValueReadQuery used by the platform:

ValueReadQuery vrq = new ValueReadQuery(
    "SELECT to_char(sysdate, 'YYYY-MM-DD HH:MM:SS.SSSSS') FROM DUAL"
);
vrq.setRedirector(new TSQueryRedirector());
...
class TSQueryRedirector implements QueryRedirector 
{
    public Object invokeQuery(DatabaseQuery query, Record arguments, Session session)
    {
        String value = (String)session.executeQuery(query);
        return ConversionManager.getDefaultManager().convertObject(
            value, java.sql.Timestamp.class
        );
    }
}

4.1.5 Proxy Authentication with Oracle Containers for Java EE (OC4J) Managed Data Sources

Proxy authentication does not work with OC4J managed data sources. Instead of using the data source provided by the application server, you must create a data source yourself.

Refer to the "Configuring Oracle Database Proxy Authentication" in the Oracle Fusion Middleware Developer's Guide for Oracle TopLink for more information.

For example, replace this code:

login.setConnector(
    new OracleJDBC10_1_0_2ProxyConnector(
        ((JNDIConnectorlogin.getConnector()).getName()
    )
);

with the following:

oracle.jdbc.pool.OracleDataSource ds = new oracle.jdbc.pool.OracleDataSource();
ds.setUser("MyMainUser");
ds.setPassword("MyPassword");
ds.setUrl("jdbc:oracle:thin:@MyServer:1521:MyDb");
login.setConnector(new OracleJDBC10_1_0_2ProxyConnector(ds));

4.1.6 Unit of Work does not add Deleted Objects to Change Set

When accessing the change set of a Unit of Work to determine what has changed, objects that are pending deletion (such as uow.deleteObject( ) and uow.deleteAllObjects( )) will not be returned from the result set.

The objects pending deletion are only available through the Unit of Work getDeletedObjects call.