7 Replies Latest reply on Mar 3, 2012 3:03 PM by Shawn Wallwork

    1 Map, 2 Data Sources

      I have 2 independent data sources that I want to map data on, by zip code.

       

      Is there any way to do this in one worksheet?

        • 1. Re: 1 Map, 2 Data Sources
          Tracy Rodgers

          So there are no common fields in the data sources?

          • 2. Re: 1 Map, 2 Data Sources
            Joe Mako

            Can you provide additional details, example data and a mock up of what you want for a result?

             

            Is each data source a different type (one Excel and other MySQL) or both the same data source type (both text files)?

            • 3. Re: 1 Map, 2 Data Sources

              Hi Tracy and Joe, thanks for the quick follow up.

               

              I have 2 very large tables of data, both on Microsoft SQL servers. For simplicity, let's say that one table holds the addresses where apples live, and the other holds addresses where oranges live. I want a simple map showing how many apples live in a zip code, and also how many oranges live in a zip code - on the same map!

               

              There are basic common address fields shared between the two tables, i.e. city, state, zip, but again, both are giant (1,000,000 + rows) tables of addresses.  I don't know how easy a direct join would be between the two tables, I've thought of using a third, "zip code" table that the apple and orange tables join to.  Also, I am exploring doing data extracts into a single table. 

               

              I like working with live data, so I am trying to set this up so I don't have to do data extracts every time I perform an analysis.  Any insight would be helpful, as doing something like what I want didn't seem immediately possible in Tableau.

              • 4. Re: 1 Map, 2 Data Sources
                Joe Mako

                Are they seperate databases or tables within the same database?

                 

                My first thought would also be to create a third data source that is a list of all possible zip codes, and then using this list as the primary data source, use a blend to bring in the aggregated counts.

                 

                In the attached workbook, you can see on the tab "Data after blend", the counts are coming from the two different data sources. you can unpackage the workbook to see/edit the data source used.

                 

                On the other tab "Not sure what Tableau is doing here", where I attempted to map, it looks like a few bugs, both in how the marks are drawn, with the extra clear sliver when only the second measure is non-null, and where it is getting the number 122 from that it is using as the upper bound for the size.

                • 5. Re: 1 Map, 2 Data Sources
                  Shawn Wallwork

                  Joe the 122 seems to be coming from the total of all apples and oranges in your example:

                  Joe-1.PNG

                  As to the slivers, I'm guessing Tableau put that in to indicate that the mark is still a pie, and not just a circle.

                   

                  --Shawn

                  • 6. Re: 1 Map, 2 Data Sources
                    Joe Mako

                    Thank you Shawn,

                     

                    This is a very strange display, as I am not showing the grand total on the map, and the slivers only show when the first measure is Null (rearrange the pills on the Measure Values shelf, and see the sliver go away or be added).

                     

                    I submitted a support request.

                    • 7. Re: 1 Map, 2 Data Sources
                      Shawn Wallwork

                      You're right about the slivers. I played with Coffee chain and produced this pie chart with a single measure:

                      Joe-2.PNG

                      So my guess was wrong.

                       

                      --Shawn