Forum Discussion
Many to One Relationships
I have a report that uses two data tables - one with transaction data that includes duplicates of various products, just with different amounts and dates; and one table with a list of unique product names. I have a Many to One relationship set up. I try to refresh data and it fails with "contains duplicate value and this is not allowed for columns on the one side of a many-to-one relationship..". The report is a copy of another file that contains the exact same two data tables with the exact same relationship - and that refreshes without any problems. Because of this I don't think it's a relationship issue. Without deleting the report and trying to recreate it, has anyone experienced this and if so was there a successful fix? I have the latest version of PowerBI installed. Many thanks!
3 Replies
Your product table must not contain any duplicates in your join column. You can do a count for each product to see which one is duplicated.
Unfortunately that's not the problem. There are no duplicates in that column and the other file I have is using the same data but successfully refreshing. Maybe Power BI is prone to random bugs or something has corrupted the file. Thanks for the idea though, it was definitely worth double-checking.
Is there any null value in your product ID?
