This post explains what needs to be done in order to display a value rather than an ID in a cell and in a combobox editor.

Please write all the necessary codes in XAML (especially the Bindings everywhere!) and in C# that is needed to solve this problem. I'd like to ask you not to suggest to me any sample codes because in those there are pre-filled into-dll-compiled datasets what are so far away from reality.

The above-mentioned post provides all the XAML and the bindings that are required. How and where a DataTable is filled does not influence the code since a DataTable is being used in both cases.

Now, since this issue seems to stump many people and has been a recurring question, I have created a sample that incorporates the 2 classes and information from the previous post: ID/Value mapping sample application