I have a Tableau dashboard file that I need to run on a monthly basis for data that is rolling twelve months.
The data is housed in an Excel worksheet. When I created the Tableau dashboard, I did not use a Custom SQL Query but rather imported the entire sheet.
The problem I am running into is the following - last month, the Excel sheet contained data starting from January 2017 to December 2017. However, this month's iteration contains data from February 2017 to January 2018 since the file is a rolling twelve months. Since Tableau can no longer find data for January 2017, it keeps giving me an error when I am trying to update the dashboard. I should add that I am only using the Total and Average columns in the file so I don't actually need the individual month columns.
Any ideas how to fix this other than recreating the entire dashboard using custom SQL?