It seems simple but I cannot find a way to implement it:
I have a table which is loaded from a database. To that table, I add (when loading) another 5 columns based on some calculations.
In addition, I have to sum up the data from already calculated 5 columns into another column (6th one) but seems to not be possible while loading the table as the newly created columns are not recognized yet.
Anyhow, this would not be a big problem as I suppose I can add an additional column to the table after it was loaded. The problem is that I have no idea how to do it.
Loading function is something like below (simplified, with fewer columns):