Entity Framework span and eager fetch

Some minutes ago I posted about the Entity Framework and fetching strategy. After a little search in the documentation, I finally found how to prefetch using a concept called * span *. Here is a LINQ query that load a department eagerly fetching the courses collection

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var query = from d
            in conn.Department.Include("Course")
            where d.Name == "Economics"
            select d;
foreach (Department dep in query) {

   Console.WriteLine("Department {0} has following courses", dep.Name);
   Int32 I = 0;
   foreach (Course c in dep.Course) {
      Console.WriteLine("{0}-{1}", ++I, c.Title);
   }
}

Using the span is simple as calling method * Include() *in the Department property of the EF context. This solves in part the problem because I still do not like that, if you forget to eager fetch or manually lazy fetch calling * EntityRef.Load() *, you can access the collection and find it empty. I think that raise an exception or some warning should be done, to warn the programmer that he is accessing a collection that is not in sync with data in the database. Accessing an unfetched collection can mislead the programmer that there are no related object in database.

Alk.

Tags: Entity Framework fetching strategy span