I have two reports from one data source that I have connected with a full join so as to keep all the data.
One is a purchase report, showing all purchases.
The other is our total list of customers ever.
They are linked via customer ID.
I applied a filter on 'purchase date' so that it only shows the last year. I was hoping it would filter the purchase report and leave the customer list intact (given that there is no purchase report field in that report)
Unfortunately what has happened is that tableau has filtered the customer list as well, so this has been shortened. How to apply a filter to just one of the reports but not the other? The data set is too large to extract without filter and then filter inside tableau....
Ok so for anyone who has the same issue I worked it out. It's very simple- there is a check box when filtering that says "include nulls". I checked this to ensure that nothing was lost from the customer list. Very easy fix for those that know, I'm surprised no one decided to point it out. Lost data has become lost faith.