That is an odd manifestation of the problem. Definitely worth investigation.
-Patrick -- Patrick Linskey BEA Systems, Inc. _______________________________________________________________________ Notice: This email message, together with any attachments, may contain information of BEA Systems, Inc., its subsidiaries and affiliated entities, that may be confidential, proprietary, copyrighted and/or legally privileged, and is intended solely for the use of the individual or entity named in this message. If you are not the intended recipient, and have received this message in error, please immediately return this by email and then delete it. > -----Original Message----- > From: Jason Hanna [mailto:[EMAIL PROTECTED] > Sent: Friday, April 27, 2007 11:55 AM > To: open-jpa-dev@incubator.apache.org > Subject: Re: Merge Detached Entity Problem > > An update - I was not using the @Version annotation in my > item definition. After updating my class with the annotation > and adding additional database column, my original reported > problem disappears. > > My first read of the documentation led me to believe the > @Version annotation was a best practice, but not necessary. > > From the OpenJPA User's Guide, Section 1.4: > > ---start > Note > > OpenJPA fully supports version fields, but does not require > them for concurrency detection. OpenJPA can maintain > surrogate version values or use state comparisons to detect > concurrent modifications. See Section 7, " Additional JPA > Mappings " in the Reference Guide. > > ---end > > I seem to have resolved my immediate issue, but perhaps > someone can set me straight on the expected behavior when the > @Version annotation is not present. > > Thanks, > -jmh > > > On 4/27/07, Jason Hanna <[EMAIL PROTECTED]> wrote: > > Hi All, > > > > I'm running into a problem developing a web application > that utilizes > > JSF and JPA. Not sure if my problem is related to an > OpenJPA bug, or a > > flaw in my approach. I'm hoping you can help. > > > > In my web application, a user selects an item to "edit" > from a table > > of all available items. They are then directed to a page > containing a > > form which allows them to modify the details of the item > they selected > > (pretty standard web app stuff). > > > > Upon submission, the backing bean connected to this form > invokes the > > update method of the item's data access object. The DAO in turn > > creates and EntityManager from the EntityManagerFactory, starts a > > transaction, merges the detached object, and commits the > transaction. > > > > If any value is modified on the item edit form, the > detached object is > > merged and successfully committed. That's good. Now for the problem: > > > > If the detached object is NOT modifed (edit form submitted w/o any > > changes) the merge will fail on the EntityManager > transaction commit > > with the following error: > > > > <2|true|0.9.5-incubating> > > org.apache.openjpa.persistence.RollbackException: > Optimistic locking > > errors were detected when flushing to the data store. The > following > > objects may have been concurrently modified in another transaction: > > [com.coincident.green.beans.User-com.coincident.green.beans.User-1] > > > > I've read through the lifecycle management documentation > and don't see > > why attempting to merge an unchanged detached entity would > result in > > an exception. > > > > I could probably detect that no updates were made at my JSF managed > > bean and avoid the merge operation altogether, but what > happens when > > my item references other managed entities and I want to utilize > > cascade merge? > > > > Hoping you all might have some thoughts. Here are a few > details about > > my environment: > > > > Sun JDK 1.5.0_06 > > Apache Tomcat 5.5.20 > > MyFaces 1.1.3 > > OpenJPA 0.9.5 (Packaged w/BEA Workship Studio and Kodo) > MySQL 5.0.27 > > (Community) > > > > Thanks! Please let me know if you require any more information. > > > > Regards, > > -jmh > > > > Jason M. Hanna > > President/Founder > > Coincident, Inc. > > > Notice: This email message, together with any attachments, may contain information of BEA Systems, Inc., its subsidiaries and affiliated entities, that may be confidential, proprietary, copyrighted and/or legally privileged, and is intended solely for the use of the individual or entity named in this message. If you are not the intended recipient, and have received this message in error, please immediately return this by email and then delete it.
