static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Model1 moddel = new Model1(); DbSet <list_station> temp = moddel.list_station; list_station s = temp.FirstOrDefault(); Random r = new Random(1000000); int id = r.Next(800000, 1000000); subscriber sub = new subscriber(); sub.GENIDXTSISSI = id.ToString(); sub.GENTYPE = "1"; sub.TYPEGROUP = "1"; sub.SUBSCRIBERNAME = id.ToString(); moddel.subscriber.Add(sub); moddel.SaveChanges(); Console.WriteLine("insert ok:GENIDXTSISSI = " + id.ToString()); //update subscriber sub1 = new subscriber(); sub1.GENIDXTSISSI = "500001"; sub1.GENTYPE = "1"; sub1.TYPEGROUP = "1"; sub1.SUBSCRIBERNAME = "ef updated:" + DateTime.Now.ToString(); moddel.Entry <subscriber>(sub1).State = EntityState.Modified; int count = moddel.SaveChanges(); Console.WriteLine("update ok:GENIDXTSISSI = 500001 ,SUBSCRIBERNAME = " + sub1.SUBSCRIBERNAME); string idv = id.ToString(); //delete subscriber sub2 = (from t in moddel.subscriber where SqlFunctions.Equals(t.GENIDXTSISSI, idv) select t).First(); moddel.Entry <subscriber>(sub2).State = EntityState.Deleted; count = moddel.SaveChanges(); Console.WriteLine("delete ok:GENIDXTSISSI = " + id.ToString()); Application.Run(new Form1()); }