8 Replies Latest reply on Jan 1, 2019 10:29 PM by tan wt

    Data blending not working

    tan wt

      Hi all,

       

      First of all, Happy New Year

       

      I am using desktop version 2018.2.3 and i am having issues in data blending. Just to note,

      1. I do not have write access to oracle db. i only can read

      2. I can't use join because 1 of the table is in Tableau Server

       

      Table 1 (Oracle)

      Fields = Start_Date, Quantity

       

      Table 2 (Excel - Primary)

      Fields = Start_Date, Month_Code

      ** Month_Code is basically month but the monthly cut off is different compare to calendar month

       

      Relationship

      1. Table 2 = Primary, Table 1 = Secondary

      2. Use Start_Date to blend with DAY,MONTH,YEAR as keys

       

      Graph

      Plot Month_Code vs Quantity (Note : Start_Date link has been established. The link icon is correct)

       

      Expectation

      Every Month_Code will have different Quantity

       

      Issue

      Every single Month_Code shows the same value which is the total Quantity of the entire population

       

      Question

      1. Is the issue related to Oracle DB?

      2. any idea on workaround?

       

      appreciate any help

        • 1. Re: Data blending not working
          Mavis Liu

          Hi Tan,

           

          Have you set the relationship for month_code?

          2018-12-31_23h03_26.png

           

           

          Then do you have it as an activated field for the blend? - ie the chain is red.

           

          2018-12-31_23h02_54.png

           

          Thanks,

           

          Mavis

          • 2. Re: Data blending not working
            Chris McClellan

            can you supply some dummy data to illustrate the problem please ?

            • 3. Re: Data blending not working
              tan wt

              date_template.jpg

               

              Hi Mavis, Chris,

               

              This is the snapshot of sample data

               

              1. Shift Start has been linked. Mavis, icon has been changed to "linked"

              2. "Month_Code" in Table 2 is not linked

              3. Chris, if i create dummy data, the blending works. But it seems (i can't be sure) it doesn't work with live connection to oracle db. is there a limitation to oracle db?

               

              Thanks

              • 4. Re: Data blending not working
                Chris McClellan

                tan wt wrote:

                 

                if i create dummy data, the blending works. But it seems (i can't be sure) it doesn't work with live connection to oracle db. is there a limitation to oracle db?

                 

                 

                 

                Ah right, so that's the key right there    It's something that Oracle is doing that Excel (I'm guessing that's your dummy data) isn't doing.

                 

                Can you create some dummy tables in Oracle (to test, not for posting here).

                 

                Also, it's worth looking at the datatype differences - specifically DATE vs DATETIME .  It might work if all fileds are DATETIME, but it might not work if you're mixing them

                • 5. Re: Data blending not working
                  tan wt

                  Hi Chris

                   

                  i don't have access to oracle db. i can only read

                   

                  i did an experiment whereby i use "table 2 - shift date" + "table 1 - Quantity". this works. So i don't think it is date data type issue

                  But when i use "table 2 - month_code" + "table 1 - Quantity", the quantity sum the entire population

                   

                  my observation is data blending only works on the actual linked fields

                  kinda frustrated right now

                  • 6. Re: Data blending not working
                    Chris McClellan

                    very weird     can you attach the spreadsheet with your dummy data, or better still the XLS & a workbook showing where it's not working.

                     

                    It should work fine I thought.

                    • 7. Re: Data blending not working
                      tan wt

                      I have done extra testing

                       

                      it seems the issue is related to datetime link which i haven't figure out the solution

                       

                      the reason i said so is because when i try to blend with non date fields, it seems to work

                      • 8. Re: Data blending not working
                        tan wt

                        date_blending.jpg

                        i have found the issue

                        it seems i need to use MDY for pairing instead of manually pair DAY,MONTH,YEAR

                         

                        but i still don't understand why DAY,MONTH,YEAR doesn't work

                         

                        i thought all fields must match?