db4o Developer Community

Hi You have very flavors, here I give just 3: 1) You can expose transactional methods in Repository clases: BeginTransaction(); RollBack(); Commit(); then in Business classes you can use it. 2) You can also play a little with contexts and create another class called UnitOfWork with those transactional methods to manage this issue. It is, ...

I have a confession. Not only am I new to db4o, but to programming in general, Java or otherwise. So please pardon me in advance for this question about transactions. I need to display queried objects in a jsp. Is there a way to do this without keeping the container open for the entire life of the thread? How is this normally done? Does one open ...

The documentation for ObjectContainer says that rollback() rolls back the running transaction while a call to commit()  starts a new transaction immedidately. So for example if I save some objects then call commit() and then rollback() right after that will that have no effect whatsoever or will that rollback() all the objects saved ...

Hello, I'm not sure how much this applies to Java (I'm a bit rusty there), but .NET has some really really easy, intuitive and useful transaction management options built in and I would love to see db4o implement these. I have implemented a Transaction Resource Manager for an ORM I was working on before, and really it's not very difficult, but ...

Java enterprise development with db4o Java™ developers can get a lot of mileage out of storing objects directly in an object-oriented database like db4o. Without support for transactions or the ability to use data in a distributed environment (and keep it secure), however, you probably won't have much use for the OODBMS. In this final installment ...

Hi Maik, The test case I provided works well in embedded mode, but in a c/s configuration the exceptions are thrown. I filed the bug under http://tracker.db4o.com/browse/COR-767.  Cheers, Andreas 

I must specify, that transactions are possible https://springmodules.dev.java.net/docs/reference/0.8/html/db4o.html even for test cases, but I hope there is more elegant way

I supplied a patch in jira. (http://tracker.db4o.com/browse/COR-738). This patch adds a new Message for just closing the socket without terminating the current transaction. I hope this is the correct handling for blobs.   - Andreas 

Hello *, when switching the database file in c/s mode and using a blob read or write operation, the BlobProcessor closes the current transaction (Is this how it should be???), but db4o continues to use this open transaction. So closing the ObjectContainer results in a NullPointerException, because the Server couldn't find the correct ...

Hi everbody,  before I start, my background: I'm developing webgames which means games that are played via a webbrowser and have MMOG-character in respect to the number of players. Currenty I'm working on such a game which is about to be completed in a few months. With the end of the project in sight I'm slowly starting to lay out the ...