public void Execute(CreateCompoundEntityModel model) { var date = _dateService.GetDate(); var simpleEntity = _database.SimpleEntities .Single(p => p.Id == model.SimpleEntityId); var anotherEntitiy = _database.AnotherEntities .Single(p => p.Id == model.AnotherEntitiyId); var a = model.A; var b = model.B; var compoundEntity = _factory.Create( date, simpleEntity, anotherEntitiy, a, b); _database.CompoundEntities.Add(compoundEntity); _database.Save(); _inventory.NotifyDataChanged(1, a); }