void Add(Models.Author author)
 {
     using (var dc = new BlogExample.Model.ModelContainer())
     {
         // automapper
         var a = new BlogExample.Model.Author()
         {
             FirstName = author.FirstName, LastName = author.LastName
         };
         dc.AuthorSet.Add(a);
         dc.SaveChanges();
     }
 }
        void Update(BlogExample.DAL.Models.BlogItem blogItem)
        {
            using (var dc = new BlogExample.Model.ModelContainer())
            {
                // automapper
                //var a = new BlogExample.Model.Author() { FirstName = author.FirstName, LastName = author.LastName };
                var b = dc.BlogItemSet.FirstOrDefault(x => x.Id == blogItem.Id);
                b.Title   = blogItem.Title;
                b.Context = blogItem.Context;
                b.AuthorToBlog.Clear();


                //b.AuthorToBlog.Add(

                dc.SaveChanges();
            }
        }