Tarn Barford

I really like the way you can script your data model from a python REPL console on the Django and the Google App Engine web frameworks.

For me it is a hands down better way of working with data in your domain model than writing SQL.

I've since wanted to do it in .NET projects I work on, but it wasn't till I was playing with Castle ActiveRecord yesterday that I decided I'd try it out.

The ActiveRecord pattern is an intuitive way of programming with data persistence, so it's also nice to script with.

It turned out to be really easy in the project I was playing with. I didn't need to write a single additional line of C# as I already had the configuration decoupled for integration testing with an in-memory SQLite database.

namespace SimpleBlog.Data
{
    public class Configuration : IBootstrapperTask
    {
        public void Execute()
        {
            Configure(GetDefaultSettings());
        }

        public static void Configure(IDictionary<string, string> properties)
        {
            InPlaceConfigurationSource source = new InPlaceConfigurationSource();
            source.Add(typeof(ActiveRecordBase), properties);
            ActiveRecordStarter.Initialize(source);
            ActiveRecordStarter.RegisterAssemblies(Assembly.GetExecutingAssembly());

        }

        ...

    }
}

I then just wrote this little script to help with the configuration, it uses the static method above and passes in the properties for working with a development database.

import clr

clr.AddReferenceToFile("SimpleBlog.Data.dll")

from System.Collections.Generic import Dictionary
from SimpleBlog.Data import Configuration

# NHibinate Setting
properties = Dictionary[str,str]()

properties.Add("connection.driver_class",
               "NHibernate.Driver.SqlClientDriver");

properties.Add("dialect",
           "NHibernate.Dialect.MsSql2005Dialect");

properties.Add("connection.provider",
           "NHibernate.Connection.DriverConnectionProvider");

properties.Add("connection.connection_string",
           "Data Source=[CONNECTION_STRING]"); # Add

properties.Add("proxyfactory.factory_class",
           "NHibernate.ByteCode.Castle.ProxyFactoryFactory,NHibernate.ByteCode.Castle");

Configuration.Configure(properties)

Using the helper script it's pretty easy to get in and start working with the data in the data model.

IronPython 2.6 (2.6.10920.0) on .NET 2.0.50727.4927
Type "help", "copyright", "credits" or "license" for more information.
>>> import ActiveRecord
>>> from SimpleBlog.Data.Models import *
>>>
>>> post = Post()
>>> post.Title = "Working with SQL sucks!"
>>> post.Content = "Try using a scripting langauge instead. It rocks!"
>>> post.Author = "tarn"
>>> post.Save()
>>>
>>> post.Id

2

>>>
>>> posts = Post().FindAll()
>>>
>>> for p in posts:
...     print p.Title, "by", p.Author
...

Hey, It's alive by tarn
Working with SQL sucks! by tarn

>>>

This is a simple example of a database agnostic data script using your domain model and a powerful scripting language. I think scripting data models like this could add a lot of value in many .NET development scenarios.

Scripting your Data Model