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aktripathi2506's avatar
aktripathi2506
Helper IV
9 years ago

Problem with Left outer join when to create the relationship between tables

Hi,   I have two tables (Table A and Table B), they both are having millions of data. In both the table I have a column name Serial number.   And when I create relation between these two tables ...
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  • jahida's avatar
    jahida
    Impactful Individual
    9 years ago
    Initial thought is that A used to have unique values in the column you're doing the relationship on, but no longer has unique values after the outer join.
    • aktripathi2506's avatar
      aktripathi2506
      Helper IV
      9 years ago

      thanks jahida,

       

      Yes to create the relation one of the table sould have unique value in that column.

       

      What I did is I exported the data into excel and check for any duplicate but I did not get any.

       

      And according to the defination of left join also it should have all the row from table A (first table). From 2nd table we only get additional column not row..right?

       

      If it was able to make relationship before the join than why not after join.

       

      • v-qiuyu-msft's avatar
        v-qiuyu-msft
        Community Support
        9 years ago

        Hi aktripathi2506,

         

        Based on my test, when you retrieve data from those three tables, then you can merge Table A with Table B use Left Outer join, it will return all of the checked column values from the Table A and matched records from the Table C. If there is no matched records in Table C, it will display as NULL in the merged table A. After apply this merge step, we can also build relationship between Table A and Table B. Please check attached .PBIX file.

         


        If you have any question, please feel free to ask.

         

        Best Regards,
        Qiuyun Yu