Join us at FabCon Atlanta from March 16 - 20, 2026, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.
Register now!Vote for your favorite vizzies from the Power BI Dataviz World Championship submissions. Vote now!
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
Solved! Go to 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
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
Most likely the table on the left contains duplicates in the join column.
Vote for your favorite vizzies from the Power BI World Championship submissions!
If you love stickers, then you will definitely want to check out our Community Sticker Challenge!
Check out the January 2026 Power BI update to learn about new features.
| User | Count |
|---|---|
| 7 | |
| 6 | |
| 5 | |
| 4 | |
| 3 |
| User | Count |
|---|---|
| 11 | |
| 10 | |
| 6 | |
| 6 | |
| 6 |