Your database should be in your local storage application.
On the desktop, to find it, in Visual Studio, open the Package.appxmanifest file, open the Packaging tab, and copy the package name.
Open the file explorer, go to the folder C: \ Users \ username \ AppData \ Local \ Packages. (Remember to replace the username with your real username. Then find the folder containing your package name.
If you open the LocalState folder, you should find your database file.

To access it through a code (will also work on the phone):
var folder = ApplicationData.Current.LocalFolder; var files = await folder.GetFilesAsync(); var dbFile = files.FirstOrDefault(x => x.Name == "myDatabase.db");
If your database was created before deploying your application, your database will be deployed to the application installation folder: to find it, use var folder = Windows.ApplicationModel.Package.Current.InstalledLocation;
For the OneDrive API you have examples:
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