db4o Developer Community

I am using dRS 6.4 to keep 3 DB4o databases in sync Lets call them db1, db2, and db3.  if I have changes in db1, I can sync it to db2 with no problems, but when I try to replicate db2 to db3 ReplicationSession can't find any changes between those databases. Has anyone seen this behavior before and knows of possible ...

Hello, everyone, I have a problem with db4o 7.2 for .net, I want to use dRS to replicate objects of specified classes which is only part of the whole class library. for example, there're many classes in the class library: class1, class2, class3, ......, How can I only replicate objects of class1 not the whole class library? I think a proper ...

Hi,  Could you provide us an TestCase or at least a StackTrace to know better this issue ? It will be well appreciated. About the GetHashCode, it's important to override well this method, not for dRS, else for the health of your application (is hand by hand with Equals). dRS doesn't looking at the hashcode to find an object. To the last ...

When DRS throws a null pointer due to its inability to find a counterpart, what does this really mean?  I keep coming across this error in my use of Db4O and DRS.  It always occurs when it is trying to replicate the field of an object.  When ever I see this error, it always fails on something that I know is represented in both ...

Hi, A NHibernate driver for Db4o isn't exists. It could be very paintful to write a driver to translate NHibernate to Db4o (think in HQL, NHibernate right now haven't an AST), rather than that, is easier to create an DAO to abstract the implementations of NHibernate and Db4o. But doing that you will is not so easy to change the interfaces and ...

dRS - db4o Replication Services - is a framework for building applications that synchronize objects bi-directionally between databases. Until recently, dRS' approach to collections followed the minimum common denominator rule - only a small set of collection types known to be supported across data stores was used for replication. One consequence ...

Dear Forum, Having: ObjectContainer containerA= Db4o.openClient(REMOTE_CREDENTIALS_REMOVED); ObjectContainer containerB=objectserver.openClient();   Doing now: ReplicationSession replication = Replication.begin(containerA,containerB);    Brings: Stack Trace: java.lang.ClassCastException: ...

Hi! Have you seen this demo? http://projects.db4o.com/wm6contactsync Here dRS is used to synchronize the device with an external db4o database using a client server connection. With regards to moving your database check you may run into trouble if the assembly name, any class name or namespace are different between your ...

Hi Simone. In order to maintain two db instances (one db4o, the other a relational database) you can use dRS, our replication system. dRS can synchronize a db4o database with a relational database and viceversa (via a Hibernate mapping). This way you can make sure that the contents are the same (the representation will be different of course ...

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