Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Enhance your career with this limited time 50% discount on Fabric and Power BI exams. Ends August 31st. Request your voucher.

Reply
Awollet33
Helper I
Helper I

Incremental Refresh Error

Hi Power BI community,

 

I want to apply incremental refreshes but I am having some problems. Firstly, I am getting this error message saying I have duplicate values and I have confirmed I do not have duplicate values in the coloumn it is saying I am. Can anyone explain why this might be the case. When I refresh from the desktop and publish it to Power BI online I have no problems but when my scheduale refresh triggers I get this error. 

Awollet33_0-1629466193361.png

 

Awollet33_1-1629466494281.pngAwollet33_2-1629466562399.png

Awollet33_4-1629466734752.png

 

 

If anyone has ran into this problem or knows why its saying I have duplicate values in a column that is all disnict your help would be greatly apprecaited! 

 

Thanks,

Adam

 

 

 

 

 

 

 

1 ACCEPTED SOLUTION
Anonymous
Not applicable

Hi @Awollet33 ,

 

Try the solution from official document.

Cause: Post dates have changed

With a refresh operation, only data that has changed at the data source is refreshed in the dataset. As the data is divided by a date, it’s recommended post (transaction) dates are not changed.

If a date is changed accidentally, then two issues can occur: Users notice some totals changed in the historical data (that is not supposed to happen), or during a refresh an error is returned indicating a unique value is not in fact unique. For the latter, this can happen when the table with incremental refresh configured is used in a 1:N relationship with another table as the 1 side and should have unique values. When the data is changed (for a specific ID), that ID then appears in another partition and the engine will detect the value is not unique.

Solution: Refresh specific partitions

Where there is a business need to change some past data from the dates, a possible solution is to use SSMS to refresh all partitions from the point where the change is located up to the current refresh partition, thus keeping the 1 side of the relationship unique.

https://docs.microsoft.com/en-us/power-bi/connect-data/incremental-refresh-troubleshoot#problem-refr... 

 

Best Regards,

Jay

View solution in original post

4 REPLIES 4
Anonymous
Not applicable

Hi @Awollet33 ,

 

Try the solution from official document.

Cause: Post dates have changed

With a refresh operation, only data that has changed at the data source is refreshed in the dataset. As the data is divided by a date, it’s recommended post (transaction) dates are not changed.

If a date is changed accidentally, then two issues can occur: Users notice some totals changed in the historical data (that is not supposed to happen), or during a refresh an error is returned indicating a unique value is not in fact unique. For the latter, this can happen when the table with incremental refresh configured is used in a 1:N relationship with another table as the 1 side and should have unique values. When the data is changed (for a specific ID), that ID then appears in another partition and the engine will detect the value is not unique.

Solution: Refresh specific partitions

Where there is a business need to change some past data from the dates, a possible solution is to use SSMS to refresh all partitions from the point where the change is located up to the current refresh partition, thus keeping the 1 side of the relationship unique.

https://docs.microsoft.com/en-us/power-bi/connect-data/incremental-refresh-troubleshoot#problem-refr... 

 

Best Regards,

Jay

parry2k
Super User
Super User

@Awollet33 make sure you are checking the full dataset from your back end source, if you have partial data in pq based on range start and end, you might not find it but once the report is published, the first time it is going to do a full load and there might be blank row which otherwise you are not seeing in PQ. You have to confirm it at the source. 



Subscribe to the @PowerBIHowTo YT channel for an upcoming video on List and Record functions in Power Query!!

Learn Power BI and Fabric - subscribe to our YT channel - Click here: @PowerBIHowTo

If my solution proved useful, I'd be delighted to receive Kudos. When you put effort into asking a question, it's equally thoughtful to acknowledge and give Kudos to the individual who helped you solve the problem. It's a small gesture that shows appreciation and encouragement! ❤


Did I answer your question? Mark my post as a solution. Proud to be a Super User! Appreciate your Kudos 🙂
Feel free to email me with any of your BI needs.

Awollet33
Helper I
Helper I

Hi @parry2k ,

 

I just checked and there are no blank or null values in that column.

 

Thanks,

Adam

parry2k
Super User
Super User

@Awollet33 do you have null/blank values in that column? The null value is not allowed, just double-check.

 

Follow us on LinkedIn

 

Check my latest blog post The Power of Using Calculation Groups with Inactive Relationships (Part 1) (perytus.com) I would  Kudos if my solution helped. 👉 If you can spend time posting the question, you can also make efforts to give Kudos to whoever helped to solve your problem. It is a token of appreciation!

 

Visit us at https://perytus.com, your one-stop-shop for Power BI-related projects/training/consultancy.



Subscribe to the @PowerBIHowTo YT channel for an upcoming video on List and Record functions in Power Query!!

Learn Power BI and Fabric - subscribe to our YT channel - Click here: @PowerBIHowTo

If my solution proved useful, I'd be delighted to receive Kudos. When you put effort into asking a question, it's equally thoughtful to acknowledge and give Kudos to the individual who helped you solve the problem. It's a small gesture that shows appreciation and encouragement! ❤


Did I answer your question? Mark my post as a solution. Proud to be a Super User! Appreciate your Kudos 🙂
Feel free to email me with any of your BI needs.

Helpful resources

Announcements
August Power BI Update Carousel

Power BI Monthly Update - August 2025

Check out the August 2025 Power BI update to learn about new features.

August 2025 community update carousel

Fabric Community Update - August 2025

Find out what's new and trending in the Fabric community.