1 Reply Latest reply on Dec 21, 2017 10:16 AM by Amber Loranger

    Data Blending Relationship and multiple Filter issue using Multiple Data Sources

    Lihos G

      I am fairly new to Tableau.

      I have two queries regarding this workbook.

      Here in this workbook I am Calculating Percentages using Inner Join and Data Blending.

      Percentages are simply calculated as : (Count of Data Source 1)/( Count of Data source 2) .

      Question 1: Here I am Calculating Percentages for Multiple Data cuts i.e. Main Product wise, Sub Product Wise, Schemewise, Customer type, Instrument type etc...

      Originally I was planning to put all this in one View and with before mentioned filters. But since I am using Data Blending, for each filter(Main Product etc) I have to create a Relationship (Edit Relationships) and when I Do this Percentages for other Data Cuts changes.

      For Example: Percentages for Main Product changes if I create a Relationship to Calculate Scheme Wise.

      For this reason, I had to add separate graphs for Each filter.

      Can Anyone Explain and possibly help Resolve this issue. As There are many Combinations of filters there will be many views

      but originally I wanted to show it in One View in a single Dashboard with Action filters to get Record Level Data.


      Question 2: If showing it in One View is not possible can Anyone help me in Making a Right Visualization choice for the Dashboard.

      As I am not that proficient in Visualization techniques and Not sure How to Accomodate this many Views on a Single Dashboard.

      Ideally I want it all to be in One Single Dashboard, or Atleast some continuity So that it is Visually effective.


      I have done All the Calculations and and they show correct Values.

      Sheets Colored in Red are Test sheets I have created for testing Values of Different Combinations of filters.

      Sheets Colored in Green are used for Dashboard (currently I have added only few views and adding a view for each combination is not feasible).



      Let me know if anyone can help me make a better visualization out of it or Solve Data Blending Issue.

      I have Attached a workbook.

      Tableau Community Forums  Tableau Desktop Certified Professional



        • 1. Re: Data Blending Relationship and multiple Filter issue using Multiple Data Sources
          Amber Loranger

          Hi Lihos,

          Maybe I am missing something, but it looks like you have both a join and a data blend between BounceLMS and LMSData. Can you explain a little more about why you are doing that? Most of the time, you should only need one or the other, and a join is often going to be more flexible than a blend (for the issues with filters and whatnot like you are describing above.)

          This article has some more information about when you might want to use joins vs. blends:

          Deciding Between Joining Tables and Blending Data | Tableau Software


          As far as the changing data you're receiving when you blend, this is expected because blending basically creates an ad hoc left join based on the linking field you selected. When you change the linking field (Edit Relationship) you also change the join, so the data will change. This article has more information about how filters work across multiple data sources:

          Filter Data Across Multiple Data Sources

          and here are some common troubleshooting steps for data blending: https://onlinehelp.tableau.com/current/pro/desktop/en-us/multipleconnections_troubleshooting.html

          Troubleshoot Data Blending

          It sounds from your description above like you are choosing different linking fields for each new filter. In most cases, this shouldn't be necessary. Ideally you want to link on one primary key field which has the same members across both data sources, or is at least at the level of detail you want in the primary data source. The message you get about relationships is probably indicating that you need to just click the link next to your chosen linking field, not re-create a new relationship for each filter.


          Looking at this dashboard, even if you can put everything into one worksheet, I don't know if you would want to. It is already pretty busy and complex, and one of the points of using Tableau is to make data visually accessible - so you can look at the dashboard and almost immediately understand the story the data is telling you. If we put all six of these worksheets into one, it might become too complicated to tell that story.


          I don't know your data or the story you want to tell well enough to advise exactly how you should change your dashboard, but I can point you to some information about best practices:

          Visual Best Practices

          6 Best Practices for Creating Effective Dashboards

          Whitepaper: What is data visualization? | Tableau Software


          If you feel like there are too many things on one dashboard, you might consider using a story so you can have several dashboards with different information all arranged in a continuous format.


          Hope this helps!

          - Amber