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DataGuy2016's avatar
DataGuy2016
Advocate IV
9 years ago
Solved

Table Merge creates duplicate records

Hi Folks,   I am stumped.   I am trying to merge two tables into a new table using a LEFT JOIN.  Both tables have unique records on each row.  When I join the tables, BI creates duplicate rows on...
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  • DataGuy2016's avatar
    DataGuy2016
    9 years ago

    The problem lay with the Data.

     

    The LEFT JOIN functionality of PowerBI works perfectly.

DataGuy2016's avatar
DataGuy2016
Advocate IV
9 years ago

The problem lay with the Data.

 

The LEFT JOIN functionality of PowerBI works perfectly.

aavilap's avatar
aavilap
Helper I
8 years ago
Hi I’m having the exact same issue when merging two tables, I see you posted that the issue lays with the data and not the merge, can I ask how you solved it? I’m pretty sure I have unique values so I believe that is not the issue, actually the merge is working on someone else’s computer but not on mine. Appreciate any hint you may provide.
  • Anonymous's avatar
    Anonymous
    Not applicable
    8 years ago

    Sadly, I still have not been able to fix this problem with the "Merge" feature.  I have resorted to using "Append" instead - and in some cases it works and in others it doesn't.  It is a very frustrating situation.

    • powergirl's avatar
      powergirl
      New Member
      8 years ago

      I got the same problem.

      Source table is an daily order table with duplicated rows, i.e. SKU ID and merged with another matching table with unique rows of SKU ID, and created randomly duplicated rows.

       

      Whatever I tried to remove duplicates or aggregated by median still not get the correct final data.

       

      My order data could get up to 20K rows and it's easily get wrong while I merged the tables.

       

      That is so annoying.

       

      Hope POWER BI experts can really solve this problem.

       

      Thanks.

      • Anonymous's avatar
        Anonymous
        Not applicable
        2 years ago

        I know this post is old, but this may help others in the future:

        Create an Index Column before the merging.

        This will mark each row with a unique sequential number.

        When the duplicate happens, it will duplicate the number as well. 

        After the merging, select the Index Column and remove duplicates.

        Remove Index column.

  • LiongMei1's avatar
    LiongMei1
    Regular Visitor
    3 years ago

    Hi, you may try to match more than one field to obtain a unique set of data match.