Hi,
We do a evaluation every other month for 3 processes which have different criterias.
Every other month I create a table excerpt like the one shown below from a table spreadsheet, so for Oct, it would be like

For Aug, also similar table excerpt exists (and there will be an excerpt for Dec and so on..)
So I used a table transformer to join both the excerpts on "Process Details" to get the following view. (I need to use an OUTER JOIN as the criterias might change over time )

Now I have a Summary excerpt, this is maintained manually ( because I enter comments which changes every other month) which would have 3 rows ,one for each process. But here the column name changes over time, so you see Oct and Aug now (but soon it will be Dec and Oct).

My goal : To calculate average per process and month combination into the Summary, so it will eventually look like below using the data in the table transformer

I was able to calculate averages using the month name as column names using queries like "SET @octnov_p2_avg_value = (SELECT AVG(CAST(T2.'Oct/Nov' AS DECIMAL)) FROM T2 WHERE ABS(T2.'Oct/Nov') > 0 AND 'Process' = "P2") AND then use UPDATE statement. (The columns will contain non-numeric data also which I filtered out.)
But I would ideally like to calculate averages by knowing the Month names from the Summary and using them to fetch data from the combined view in the transformer,so the month names are not hardcoded anywhere. Can this be done ?