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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

Hi there,

 

I am running the merge again and it is still creating duplicate records from the LHS table.  The LHS table has unique rows of data.  So I have 183,000 records merged into 187,000 records post join.

 

I cannot understand why BI would create an exact duplicate of the LHS row in the merged table?  Could it possibly be because the primary key is duplicated?  I know that this is not scientifically viable however this is the closest I can get to a primary key.

 

 

 

J_R_Cribb's avatar
J_R_Cribb
Helper I
8 years ago

Hi DataGuy2016, 

 

If you haven't already found a solution...

 

I had a similar issue where LEFT JOIN was creating duplicates, resulting over 1000 rows of data where I should have just 85.

 

I solved the issue by expanding the relative columns as an aggregate, instead of just an expansion.

 

Hope that this makes sense.