EF4 LINQ Ordering Parent and all child collections with Eager Loading (.Include())

Question

I am doing hierarchical data binding on a grid, and I need to have the database server perform the sorting on my objects. I can easily sort the parent collection, but I can

Answer 1

If you need to have Ordering or Filtering on inner navigation properties (e.g. Models) then you cannot eager load them using Include method anymore. Instead, you can use EntityCollection.CreateSourceQuery Method like this:

List years = db.Years.OrderBy("it.Name").ToList();
foreach(year in years) 
{
    var makesQuery = year.Makes.CreateSourceQuery().OrderBy(m => m.Name);
    year.Makes.Attach(makesQuery);  

    foreach(make in year.Makes) 
    {
        var modelsQuery = make.Models.CreateSourceQuery().OrderBy(m => m.Name);
        make.Models.Attach(modelsQuery);

        foreach(model in make.Models) 
        {
            var colQuery = model.Colors.CreateSourceQuery().OrderBy(c => c.Name);
            model.Models.Attach(colQuery);        
        }
    }
}

This way, the years object will be constructed with having all of its navigation properties ordered.