# Duplicates after Power Query Left Join



## ajw5173 (Apr 12, 2016)

Hi,

I am just wondering if anyone knows why after each time I do a left join merge with Power Query I get a lot of duplicate rows?  Is there a reason within my data for why this is happening or is it something that happens normally?

Thanks!


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## ralliartur (Apr 13, 2016)

You are using column (in join) which is not distinct in one of the tables. This is the only reason.


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## BilalCh (Mar 31, 2020)

ralliartur said:


> You are using column (in join) which is not distinct in one of the tables. This is the only reason.


That would be correct. Just like when you join tables in Access with non-unique values.

@[U]ajw5173[/U] - I would suggest that you either ensure that the join field (column) in the first table has unique values, or else you may join multiple columns (the same ones) from both tables that combine to mimic a unique (combination of) value


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