Hi, all tableau talents,
I met a problem on Data Blending and Level of Detail.
Actually, my question is quite like this one data blending & overlapping text and unfortunately it is still not solved.
I can't supply the original workbook, so I make a sample one with 2 Excel datasources as attached.
The problem I met is, when I create a relationship between the two tables based on some fields "Category", "Country" and "Period"(I think they are used as foreign keys), Tableau requests me to use these fields somewhere in the Sheet or else the blending won't affective.
Then I have to drag "Category", "Country", "Period" into Level of Detail, because I don't want them to be shown in the table. And in my actual workbook, it is a pie chart, and I don't want any dimension in the Column or Row to show several pie charts.
For the "Category" and "Country" they are fine, because they are single selected by filters, so put them into Level of Detail won't bring overlap problem.
However "Period" brings the problem, because I want it as multi-selected, user can select more than one period to analyze. But, if I select two periods, as the "Period" is in the level of detail, the table will show overlap data. If I remove "Period" from level of detail, the two datasources are not connected correctly.
I tried to build a parameter of periods, and make two calculation fields in both datasources, and make them equal to same value, something like IF [Period]=[parameter].[period] THEN "yes" ELSE 'no" END. Then use this calculation field as the connection instead of "Period" and drag this calculation field into Level of Detail. But I find out parameter doesn't support multi-select! !.............
Also I thought about Edit connection and join two datasources, however when I calculate the "Country Revenue" by Window_Sum, I still need to put "Period" into Level of Detail to get correct value.
So, in general, I found the key point is, how to blend the data without put Dimensions into Level of Detail?
Thanks a lot.