Would it make any sense to add one more overload to the FetchProjection method on the DataAccessAdapter object that used a DataTable instead of a DataReader?

adapter.FetchProjection( valueProjectors, projector, datatable );

I realize in this case it would not actually go out to the database to do a query, but it seems easier than creating another class.

I can make a use case where a datatable gets populated, serialized, transmitted, deserialized back to a datatable at which point it needs to get projected onto an entity collection for validation, business processing and finally persisting to a database.

Sure I can write the code to do that, just wanted to offer it as a core suggestion.

Unless of course there is already a way to populate an entity collection from a datatable and I missed it in the docs...

Very old thread, which contains a small routine which should do the trick: http://www.llblgen.com/tinyforum/Messages.aspx?ThreadID=453 You might want to use the column names as indexers instead to make it more robust.