Save changes to the database using entity structure

Question

I have a simple query that loads data from two tables into a GUI. I save the downloaded data to a widely Clients currentlySelectedClient object Clients currentlySelectedClient .

 using (var context = new EntityBazaCRM()) { currentlySelectedClient = context.Kliencis.Include("Podmioty").FirstOrDefault(d => d.KlienciID == klientId); if (currentlySelectedClient != null) { textImie.Text = currentlySelectedClient.Podmioty.PodmiotOsobaImie; textNazwisko.Text = currentlySelectedClient.Podmioty.PodmiotOsobaNazwisko; } else { textNazwa.Text = currentlySelectedClient.Podmioty.PodmiotFirmaNazwa; } } 

So now, if I wanted to:

1) Save the changes made by the user, how can I do this? Should I prepare something on the database side? How to process several tables (some data goes here, some there)? My current code seems to be writing. KlienciHaslo is just great, but it doesn't affect Podmioty at all. I tried different combinations, but no luck.

2) Add a new client to the database (as well as save information in the appropriate tables)?

  currentClient.Podmioty.PodmiotOsobaImie = textImie.Text; // not saved currentClient.Podmioty.PodmiotOsobaNazwisko = textNazwisko.Text; // not saved currentClient.KlienciHaslo = "TEST111"; // saved using (var context = new EntityBazaCRM()) { var objectInDB = context.Kliencis.SingleOrDefault(t => t.KlienciID == currentClient.KlienciID); if (objectInDB != null) { // context.ObjectStateManager.ChangeObjectState(currentClient.Podmioty, EntityState.Modified); //context.Podmioties.Attach(currentClient.Podmioty); context.Kliencis.ApplyCurrentValues(currentClient); // update current client //context.ApplyCurrentValues("Podmioty", currentClient.Podmioty); // update current client } else { context.Kliencis.AddObject(currentClient); // save new Client } context.SaveChanges(); } 

How can I reach both?

Change answer (doesn't save anything):

 currentClient.Podmioty.PodmiotOsobaImie = textImie.Text; // no save currentClient.Podmioty.PodmiotOsobaNazwisko = textNazwisko.Text; // no save currentClient.KlienciHaslo = "TEST1134"; // no save using (var context = new EntityBazaCRM()) { if (context.Kliencis.Any(t => t.KlienciID == currentClient.KlienciID)) { context.Kliencis.Attach(currentClient); // update current client } else { context.Kliencis.AddObject(currentClient); // save new Client } context.SaveChanges(); } 

Answer 1

Apparently ApplyCurrentValues only works with scalar properties.

If you attach currentClient , then related objects should also be attached, which means that they will be updated when you SaveChanges()

But you will get an Object with the key exists exception because you are already loading the object from the database into the objectInDB variable. A context can contain only one copy of Entity, and it knows that currentClient same as objectInDB , therefore it throws an exception.

Try this template instead

 if (context.Kliencis.Any(t => t.KlienciID == currentClient.KlienciID)) { context.Kliencis.Attach(currentClient); // update current client } else { context.Kliencis.AddObject(currentClient); // save new Client } 

or if you use an identifier as an identifier, then

 // if the ID is != 0 then it an existing database record if (currentClient.KlienciID != 0) { context.Kliencis.Attach(currentClient); // update current client } else // the ID is 0; it a new record { context.Kliencis.AddObject(currentClient); // save new Client } 

Answer 2

After some work and Kirk's help about the ObjectStateManager error that I received, I managed to fix it. This code allows me to save both changes in both tables.

  currentClient.Podmioty.PodmiotOsobaImie = textImie.Text; currentClient.Podmioty.PodmiotOsobaNazwisko = textNazwisko.Text; currentClient.KlienciHaslo = "TEST1134"; using (var context = new EntityBazaCRM()) { if (context.Kliencis.Any(t => t.KlienciID == currentClient.KlienciID)) { context.Podmioties.Attach(currentClient.Podmioty); context.Kliencis.Attach(currentClient); context.ObjectStateManager.ChangeObjectState(currentClient.Podmioty, EntityState.Modified); context.ObjectStateManager.ChangeObjectState(currentClient, EntityState.Modified); } else { context.Kliencis.AddObject(currentClient); // save new Client } context.SaveChanges(); }