Merge issue

[Anonymous]

Dear Power BI community,

I tried to merge two files based on same customer ID (some customer ID doesn't have matches) using left outer join but it turns out that when I perform a verification after the match, the total order quantity before and after is different. Could anyone tell me what and why is this happening? Thanks

[AnkitKukreja · Accepted solution]

Hi
This could be due to duplicates in your left or right table.
Left is easy to understand, but in right for example if you've duplicate Cust ID then those are also getting merged into your existing data which is increasing your count.

My advice, try count rows under transformin Query editor and remove duplicates and then try the same step, it would help you identify the issue.

Thanks,
Ankit Kukreja
www.linkedin.com/in/ankit-kukreja1904

[MattAllington]

Most likely the table on the left contains duplicates in the join column.