Orion and Row-Locking

[Ratz, Peter]

Hello,

i just try to find out how i can implement some kind of optimistic locking
with my EJBs.
One part of this is, to include a findByPrimaryKeyForUpdate method in my
EJBs..
This method gets the primary-key and a timestamp as parameter. If the finder
method
finds the record -> checks if there is a timestamp change -> no changes ->
update. To prevent concurrent updates between
the finder method and the update the finder should read with "FOR UPDATE"
sql option.
Whenever i include this within my orion-ejb-jar.xml 

<finder-method query="$id = $1 AND $lastModified = $2 FOR UPDATE">
<!-- Generated SQL: "select OBJ_CL.CLID, OBJ_CL.CL, OBJ_CL.CLLMFD from
OBJ_CL where OBJ_CL.CLID = ? AND OBJ_CL.CLLMFD = ? FOR UPDATE" -->
<method>
        <ejb-name>Client</ejb-name>
        <method-name>findByPrimaryKeyForUpdate</method-name>
        <method-params>
        <method-param>long</method-param>
        <method-param>java.sql.Timestamp</method-param>
        </method-params>
</method>
</finder-method>

i get the following error:

java.sql.SQLException: ORA-01002: FETCH on invalid or closed cursor

The whole work is controled by a OptimisticLockingService Bean (Stateless
Session Bean). The
Method updateEntity(...) starts the update. This method has the attribute
"TRANSACTION_NEW".

The used CMP-Bean with the findByPrimaryKeyForUpdate method has
"TRANSCATION_REQUIRED".


Thanks

Peter