I have a table with three columns. I want to be able to count all the unique values across the 3 columns. Basically, in the end, I would like to have a column with each ID found in the 3 previous ones, but only once (thus, only have unique values) - a column with the total number of unique values, from the 3 initial ones.
Any ideas on how to do that or whether it’s possible to do it?
Thanks a lot!