using (var context = new BloggingContext())
        {
            using (var transaction = context.Database.BeginTransaction())
            {
                context.Blogs.Add(new Blog {Url = "http://www.zyiz.net/xilie-293.html"});
                context.SaveChanges();

                context.Blogs.Add(new Blog {Url = "http://www.zyiz.net/"});
                context.SaveChanges();

                transaction.Commit();
            }
        }