static void Main(string[] args) { using (DOCUWARE_TABELLENEntities context = new DOCUWARE_TABELLENEntities()) { List <double?> result = context.test_Hauptverant.Select(x => x.Objektschluessel_Liegenschaft).Distinct().ToList(); var GroupResult = context.test_Hauptverant.GroupBy(x => x.Objektschluessel_Liegenschaft).ToList(); //Console.WriteLine(string.Join(Environment.NewLine, result)); foreach (var item in GroupResult) { Test_Hauptverant firstItem = item.First(); Test_Hauptverant newEntry = new Test_Hauptverant(firstItem); newEntry.Set_COO_AL(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_COO_GF(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_CEO_AL(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_Leitung_Finanzen_AL(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_Leitung_Mietbetreuung_AL(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_Leitung_Projektsteuerung_AL(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_Leitung_Rechnungswesen_AL(newEntry); context.test_Hauptverant.Add(newEntry); newEntry = new Test_Hauptverant(firstItem); newEntry.Set_Leitung_Recht_AL(newEntry); context.test_Hauptverant.Add(newEntry); } context.SaveChanges(); Console.ReadLine(); } }