Has anyone tried to get db4o to work with Powershell? I cannot get the sample code to write an object to the db4o database within Powershell. I can when using a simple cmd.exe console application. For example the code in this posting works fine as a console application:

http://developer.db4o.com/forums/post/50440.aspx

However when I create a cmdlet using similar code and execute my newly created cmdlet, the file is created however no classes are written and no error messages:

using System;
using System.Collections.Generic;
using System.Text;
using System.Management.Automation;
using System.Collections;
using Db4objects.Db4o;
using Db4objects.Db4o.Config;

namespace db4o
{
    [Cmdlet(VerbsCommon.Set, "Db4o")]
    public class SetDb4o : Cmdlet
    {

        protected override void ProcessRecord()
        {
            IConfiguration config = Db4oFactory.NewConfiguration();
            config.ExceptionsOnNotStorable(true);

            IObjectContainer db = Db4oFactory.OpenFile(config, "sampler.db4o");
            DateTime myTime = DateTime.Now;
            Console.WriteLine("Time is {0}", myTime);
            db.Store(new Wrapper(myTime));
            db.Commit();

            IObjectSet items = db.QueryByExample(DateTime.Now);

            WriteObject(items,true);

        }
    }

    public class Wrapper
    {

        public DateTime _date;
        public Wrapper(DateTime date)
        {
            _date = date;
        }

    }
}
 

 I have been trying to get something to work myself and I have been unable to get it to work. After you have run it as a command line were you able to use an existing utility to examine the database? I actually created a cmdlet that used a datetime object. The cmdlet ran correctly but none of the existing tools such as Object Manager could read the database. 

They're using a seperate method called config, just simplifying a little by directly using a variable config instead. Agreed about console.writeline although it seems to works fine in Powershell. I've also tried a dozen or so variations of my own own code with no success actually writing to the db4o file. I can create the cmdlet successfully and run Set-Db4o from Powershell the file, in the sample code, file sampler.db4o gets created its just that nothing is actually written to file whereas nearly identical code in a classic console application works fine.

This is a difficult challenge, db4o is implemented through interfaces which Powershell without implementing a provider has little understanding of.  In addition db4o as mentioned in the original link requires a true class and cannot work with value types. It also cannot work with PSobject type (the db4o file will fill with several hundred MB of data for even simple objects before having to kill it). And then there's another problem of db4o requiring strong static types where in Powershell we don't have that issue. There might be some things in .NET 3.5 to get around the typing issues, however since we're using Powershell V1 we have to use .NET 2.0 . 

But, for now I'm just trying to do the most basic thing possible with little success. I'm starting to think the challenge is also beyond my current abilities and you would need a deep understanding of db4o internals and implementation to make it work with Powershell.

 this is what I have:

using System;

using System.Collections.Generic;

using System.Text;

using System.Management.Automation;

using System.Collections;

using Db4objects.Db4o;

namespace DB4O

{

    [Cmdlet(VerbsCommon.Add, "db4oRecord", SupportsShouldProcess = true)]

    public class Add_db4oRecord : PSCmdlet

    {

        private string _FileName;

        private PSObject _Value;

        IObjectContainer database;

        #region Parameters

        [Parameter(Position = 0,

             Mandatory = true,

             ValueFromPipelineByPropertyName = false,

             HelpMessage = "To be written")]

        [ValidateNotNullOrEmpty]

        public string FileName

        {

            set { _FileName = value; }

        }

        [Parameter(Position = 0,

           Mandatory = true,

           ValueFromPipeline = true,

           HelpMessage = "To be written")]

        [ValidateNotNullOrEmpty]

        public PSObject Value

        {

            set

            {

                _Value = value;

            }

        }

        #endregion

        protected override void BeginProcessing()

        {

            base.BeginProcessing();

        }

        protected override void ProcessRecord()

        {

            try

            {

                Db4oFactory.Configure().ExceptionsOnNotStorable(true);

//               

                database = Db4oFactory.OpenFile(_FileName);

                //DateTime Test = new DateTime(2008, 12, 25);

                TestClass ThisTest = new TestClass();

                ThisTest.Property = "Something";

                database.Store(ThisTest);

                database.Close();

                //database.Store(_Value.BaseObject);

            }

            catch (Exception)

            {

            }

        }

        protected override void EndProcessing()

        {

            base.EndProcessing();

        }

    }

}

Using Export-CLIXML is basically equivalent to using  file based storage for each object. Let's say you have 12 objects you'll end up with 12 files. Using a database, in this case db4o, the physical implementation of files is abstracted away and you only have to write your objects to one database. The database, db4o, also implements a query language which is supposed to make retrieving objects more efficient and simplier than XML serialization.