I have three SharePoint lists and am using a left join to join the tables. The first two tables join correctly and produce expected results, but when I try to join the third it doesn't recognized the field to join on in some cases and returns null values where I would expect multiples rows returned. I can see the id in excel and SharePoint but tableau seems to be selective on recognizing the field and makes the join in some cases but not in others. I linked the SharePoint lists to Excel created and connection in Tableau to Excel and using the same fields to join as the SharePoint connection was able to make the joins and got the expected results. It seems Tableau changes the SharePoint data for some reason. Does anybody have any insights to this. I also tried blending the data, but since the third table returns multiple results I get the asterisk.
I am curious if there is possibly something in the data on Sharepoint causing the error. Maybe leading or trailing spaces for the values that are not joining as expected? The join relationships can also be updated using the following: