EF 4: Removing child object from collection does not delete it - why?

Question

I use Entity Framework 4 and I have parent - child relation with \"Cascade Delete\" set. So i would expect when i remove a child from the parent that the child is deleted wh

Answer 1

I use this extension in order not to add a method in DAL just to delete an entity (code taken from http://blogs.msdn.com/b/alexj/archive/2009/06/08/tip-24-how-to-get-the-objectcontext-from-an-entity.aspx):

public static void Delete(this EntityCollection collection, T entityToDelete) where T : EntityObject, IEntityWithRelationships
{
    RelationshipManager relationshipManager = entityToDelete.RelationshipManager;

    IRelatedEnd relatedEnd = relationshipManager.GetAllRelatedEnds().FirstOrDefault();
    if (relatedEnd == null)
    {
        throw new Exception("No relationships found for the entity to delete. Entity must have at least one relationship.");
    }

    var query = relatedEnd.CreateSourceQuery() as ObjectQuery;
    if (query == null)
    {
        throw new Exception("The entity to delete is detached. Entity must be attached to an ObjectContext.");
    }

    query.Context.DeleteObject(entityToDelete);
    collection.Remove(entityToDelete);
}

So I then delete an entity like Order.Products.Delete(prod).

Constraints to use the extension are:
- Entity must have relationships;
- Entity must be attached to ObjectContext.