Error(?) while changing relation by changing relation id property

I have to change relations by changing the relation id property. The change is done not completely. I attach an example to show this.

Please do the following:

1. Unzip the code
2. Add Mindscape dlls and SQLite dll to Lib folder
3. Run the solution
4. Click "AddStoreysAndApp"
5. Expand "Storeys" and "Appartments" in the tree
6. Click i.e. on "Appartment9" and then click "ChangeData". The appartment will be reallocated to another storey (the storey which is first on the IEnumerable list, so it looks a little random). The reallocation is done by changing the StoreyId field of appartment - method DMPProject.ChangeDataExecute.
7. Look at the expanded Storey branch. For one of the storeys, the Appartments.Count is equal 2, but for none there's Appartments.Count=0. It looks like LightSpeed did the following:
   • changed Appartment->Storey relation
   • added Appartment to the new Storey.Appartments EntityCollection
   • DIDN'T remove Appartment from the old Storey.Appartments EntityCollection
8. Restart the application and expand the tree - now everything is correct. So the change on the database was done correctly.

I have tested it with the nightly build of 08.12.2010 (Dec 8th), because the official release has the bug with entity map and Guids (one of my previous forum threads).

In this case I could change the relation using the relation property (not the relation id property) - you can see it in the commented-out code. Then it works fine. However changing the relation through relation id property is essential for Undo system - I cannot store object references in UndoList.

I'd like to kindly ask if there's a chance to get answer on this post. I know that I'm still not your client, but the answer is essential to finish my prototype and to recommend LightSpeed to my colleagues in order to buy it.

There will be a fix for this issue in the next nightly build.

There is an outstanding issue where if you change a foreign key to the ID of an entity which has not yet been loaded, then load that entity and its collection, the count will still be incorrect:

gadget.WidgetId = 44;  // Widget 44 is not yet loaded
Debug.WriteLine(FindById<Widget>(44).Gadgets.Count);  // will not include gadget

The workaround for this is to ensure that the new parent is loaded before performing the assignment:

FindById<Widget>(44);
gadget.WidgetId = 44;
Debug.WriteLine(FindById<Widget>(44).Gadgets.Count);  // will be correct

Thank you for the answer and information about the "late loading" issue. I will download the nightly build as soon as it's available and check it out.

It works fine. Thank you.