public static class ObjectSetHelper
    {
        public static T Insert<T>(this ObjectSet<T> objectSet, T value)
            where T : class
        {
            objectSet.AddObject(value);
            try
            {
                objectSet.Context.SaveChanges();
            }
            finally
            {
                objectSet.Detach(value);
            }
            return value;
        }

        public static T Update<T>(this ObjectSet<T> objectSet, T value)
            where T : class
        {
            objectSet.Attach(value);
            objectSet.Context.ObjectStateManager.ChangeObjectState(value, System.Data.EntityState.Modified);
            try
            {
                objectSet.Context.SaveChanges();
            }
            finally
            {
                objectSet.Detach(value);
            }
            return value;
        }

        public static void Delete<T>(this ObjectSet<T> objectSet, T value)
            where T : class
        {
            objectSet.Attach(value);
            objectSet.Context.ObjectStateManager.ChangeObjectState(value, System.Data.EntityState.Deleted);
            try
            {
                objectSet.Context.SaveChanges();
            }
            catch
            {
                objectSet.Detach(value);
                throw;
            }
        }
    }