I have a simple object with a Guid as field public Guid _id, this field is indexed. config.Common.ObjectClass(typeof(ConfigurableObject)) .ObjectField("_id").Indexed(true); When I open the databasefile in the ObjectManager Enterprise, it shows me that the field is indexed! But my queries are damn slow. It takes up to 5!! second...
I'm building a small web application with ASP.NET MVC 2, using db4o as a datastore. I have added an HttpModule—as per the example here—to give the application access to the db4o database, and everything is working perfectly on my development machine under the VS2008 ASP.NET Development Server. However, when I deploy the app to my web h...
I'm experimenting with db4o as a data store, so to get to grips with it I thought I'd build myself a simple issue tracking web application (in ASP.NET MVC). I've found db4o to be excellent in terms of rapid development, especially for small apps like this, and it also negates the need for an ORM. However, having come from a SQL Server/M...
hi, i am using db4o in a asp.net web application, as you know when db4o returns a list of objects they are not ordered. in my website, i run a query and get the last object in the results and work on it (some processing and then update one of its fields). my question is, if when i am working on that object , if another user arrive and...
I want to change all objects that match a condition to use a specific/new subclass. There are no other subclasses being used with the stored objects, so its in all cases a change from the base class to its subclass. In order to keep all references pointing to these objects, I tried using bind to replace them with new instances of the s...
I have an object model that I want to store using an embedded database. I have so far been looking at db4o, NHibernate to SQLCE (w/ linq), and RavenDB. This would be used in a desktop C# application. The key features I am looking to leverage are: Linq or similar for queries (no SQL or HQL), Embedded data engine, pocos, poco first model,...
I am following the example here: http://developer.db4o.com/Forums/tabid/98/aft/10114/Default.aspx to setup my MVC2 app with db4o using an HttpModule. I also have a LINQPad instance open to query the data as I develop. The web app seems to work like a charm, but LINQPad keeps getting DatabaseFileLockedExceptions until I close down the w...
I have just started writing my first webapp using java/wicket/db4o and all technologies are new to me so please forgive what might be a daft question. I have created a simple MyDao singleton class that connects to a file-based db4o database and I can write some objects into it and read them back. The problem I have is each time I redepl...
Hi, Is there a way (meta property maybe) to tell db4o to simply ignore a specific property of a class? I can't see anywhere to do that.. For my purpose I have a bunch of data entity that i need to persist now and then. I also sometimes need to hold a ref to a UI element associated with it, but I don't want db4o to persist that elemen...
How can I know when a db4o started from code has finished? Doc mentions it does the backup in a separate thread, but doesn't mention anything about when it finishes. The method doesn't receives any callback. ...
I want to store images in Db4o using Blobs. How can I store them and how do I get them out again? ...
Is there a way to get a Db4o Blob out of the Database without storing it to disk? I only found the method void com.db4o.types.Blob.writeTo(File arg0) ...
Hello, I would like to do Mysql to Mysql replication using drs. Is it possible to do the same without storing data in db4o? I just want to use drs replication using Hibernate. Any positive/negative experience with drs? ...
Hi, I'm working on a project for android that uses an external library, db4o. Well, I've created a test project and I was trying to test my PersistenceManager, an object that controls the database life-cycle and exposes part of the ObjectContainer api (ObjectContainer is an object from db4o library). When I started to write the tests, I...
How can I do this? I stored an object in db4o, e.g: class Person { string _name; int _age; } now, after hundrets of Persons stored in the db, I've added a new field: class Person { string _name; int _age; bool? _newField; } When I load the old classes with the new class, the _newField will be null or the defaul...
I have tried the Object Manager and the Boo browser, but none of these work with the latest DB4O file format. ...
Hi all, I need a db4o viewer for a Linux box running Java. I noticed this post was for a .net client, but I don't have Windows and don't intend to. Is there something I can use? I checked out some projects, but they look like they haven't released any files yet so I haven't found anything that will work yet. Walter ...
Hi all, I would like to have unique constraints operate on more than 1 field for several entities. How can I achieve this with db4o? Thanks, Walter ...
I'm struggling to come up with a good way of adding a bidirectional relation in OO model. Let's say there is a Customer who can place many Orders, that is to say there is a one-to-many association between Customer and Order classes that need to be traversable in both directions: for a particular customer it should be possible to tell all...
Let's say we want to build a big social network (because social networks are all the rage at the moment). We'll start with a simple premise that anyone who wants to use our social network should be able to register under their name and then become friends or fall out with other people registred with us: import scala.collection._ class ...