Architecture BLL with custom objects

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C#

architecture

database

Hi,
I am developing a website with ASP.NET.
I have created a DAL class library project, a BLL class library project and the actual ASP.NET web application project.
From the ASP.NET web application prject I added a reference to the BLL project.
In the Bll project I created classes that map each database table. Any of these classes will call a generic method in the DAL that will return IList<T> where T can be a class.
So if I want to get all the orders from the database, I call a method in the DAL like this:

List<Order> orderList = DAL.GetAll<Order>("select * from sqlOrder");

The problem is:

If I want to get the results of a select statement which contains data from 3 different tables(therefore having 3 joins), I cannot use the generic method anymore because the raw dataset returned after running the sql statement can not be converted to any one single class.

In the end I should also mention that I preffer to build this system using .NET Framework 2.0 since I have no experience with LINQ/NHIBERNATE or any other ORM tools, but any ideas are welcomed.

Thanks in advance,

Valentin.