Entity Framework: Navigation Properties Issue

Question

I am working with Entity Framework code-first, and I have a class Course which has a navigation property Students:

public virtual C         


        

Answer 1

If you were to use proper variable typing then you would see what is happening. The entire set is lazy loaded loaded into memory by the navigation property.

//user is an instance of the class User referenced by DbSet
//when you lazy load a navigation property in that set, it loads the data
ICollection allStudents = user.Students;

//At this point, all of the data was lazy loaded
//But the Where creates an IEnumerable of the in memory set
IEnumerable activeStudents = allStudents.Where(n => n.Active);

//At this point, the IEnumerable is iterated, and a List is returned
List listOfActiveStudents = activeStudents.ToList();