Power Query - Merge Duplicating

[Anonymous]

Good morning,

I am getting a strange effect when I try to do a merge using a left outer join.

I have my facts table and I am trying to look up certain descriptives from a certain dimensions table using a left outer join in power query.

Before I do the merge, my numbers are ok, but after I do the merge, my numbers seem to be multiplied .

I am trying to merge on a text column with which is a unique account code in the dimensions table.

What could I be missing that produces this sort of multiplier effect. I dont want the figure in the facts table to be multiplied

Thank you for any assistance.

Regards

Herbz

[ImkeF · Accepted solution]

Hi @Anonymous ,

unlike the VLOOKUP in Excel, a left outer join in Power Query will return multiple values and therefore duplicate your fact table rows if there are multiple matches in the lookup table.

To prevent this, you can remove duplicates on the merge-column(s) of the lookup table before the join.