c# - How does Entity Framework work with recursive hierarchies? Include() seems not to work with it

Question

I have an Item. Item has a Category.

Category has ID, Name, Parent and Children. Parent and Children are of Category too.

When I do a LINQ to Entities query for a specific Item, it doesn't return the related Category, unless I use the Include("Category") method. But it doesn't bring the full category, with its parent and children. I could do Include("Category.Parent"), but this object is something like a tree, I have a recursive hierarchy and I don't know where it ends.

How can I make EF fully load the Category, with parent and children, and the parent with their parent and children, and so on?

This is not something for the whole application, for performance considerations it would be needed only for this specific entity, the Category.

Answer 1

Instead of using the Include method you could use Load.

You could then do a for each and loop through all the children, loading their children. Then do a for each through their children, and so on.

The number of levels down you go will be hard coded in the number of for each loops you have.

Here is an example of using Load: http://msdn.microsoft.com/en-us/library/bb896249.aspx