1 Reply Latest reply on Nov 2, 2017 2:37 PM by Chris McClellan

    Data source blending

    Joel Thanos

      Hi Guys,

       

      I have two data sources, that I want to blend in Tableau.

      For simplicity, let's assume that my data sources (from a different source) look as follows:

       

      Source 1:

      Date
      ABC
      1-11-17123
      2-11-17123
      3-11-17123
      4-11-17123
      5-11-17123

       

      Source 2:

      Date
      Z
      X
      Y
      1-11-17321
      2-11-1732

      1

      3-11-17321
      4-11-17321
      5-11-17321

       

      I simply want to blend these two sources, so that my data source looks like this:

       

      Date
      A
      B
      C
      Z
      Y
      X
      1-11-17123321
      2-11-17123321
      3-11-17123321
      4-11-17123321
      5-11-17123321

       

      So basically, I want the columns of the second data source to be just added next to the columns of the first data source. This does not seem like to much of a problem, but somehow it still is for me. When I drag my second sheet to the field, I have to join. I have to choose inner, lef, right or fool outer. Also I need to select join clause. I don't really know what this is, and whatever I do, my data disappears.

      How can I do this?

       

      With kind regards,

      Joel

        • 1. Re: Data source blending
          Chris McClellan

          A join is what you want to do, but the join type is the question.

           

          In your example data, you should only join on Date because it's the only common field

           

          inner - will only return the data when the same date is in both data sources

          left - if you add Source 1 first, you will always get Source1 values and also Source2 if the record exists

          right - if you add Source1 first, you will always get Source2 values and also Source1 if the record exists.

           

          With your sample, it doesn't matter because the same dates are in both datasets.  In reality you might be missing dates in either date source so the join type does matter.

           

          If you're still facing problems, post a twbx or more requirements on what you want to do