Forum Discussion
Table Merge creates duplicate records
- 9 years ago
The problem lay with the Data.
The LEFT JOIN functionality of PowerBI works perfectly.
Hi DataGuy2016,
According to your description, I just tested it in my environment. The Merge Queries option works all fine for me without the issue.
I assume the issue is with your data. Could you post your table structure with some sample data which can reproduce the issue? It's better to share a sample pbix file. You can upload it to OneDrive or Dropbox and post the link here. Do mask sensitive data before uploading.:smileyhappy:
In addition, here is a similar thread for your reference.:smileyhappy:
Regards
Hi there,
I am running the merge again and it is still creating duplicate records from the LHS table. The LHS table has unique rows of data. So I have 183,000 records merged into 187,000 records post join.
I cannot understand why BI would create an exact duplicate of the LHS row in the merged table? Could it possibly be because the primary key is duplicated? I know that this is not scientifically viable however this is the closest I can get to a primary key.
- J_R_Cribb8 years agoHelper I
Hi DataGuy2016,
If you haven't already found a solution...
I had a similar issue where LEFT JOIN was creating duplicates, resulting over 1000 rows of data where I should have just 85.
I solved the issue by expanding the relative columns as an aggregate, instead of just an expansion.
Hope that this makes sense.
- Anonymous8 years agoNot applicable
I am having the same problem with my data. And no, I do not understand your answer to "expand as an aggregate," will you please clarify?
I know this is an old thread, but if someone else is still reading this thread and would like to offer help, I appreciate it!
- J_R_Cribb8 years agoHelper I
Hi Anonymous,
I have created a quick sample that I hope helps explain my method. It may not work with your data, but it did fix the issue with mine!
I have two tables, I would like to merge 'Customer Type' with 'Customer Name'.
Customer Name Table
Customer Type Table
I would like to merge using the 'ID' column in both, to bring in the 'Cust Type' field from table 'Customer Type' into table 'Customer Name'.
Merge Options
Once successfully merged, I see the below:
I now have the option to expand that column of the merged table to bring in data from the 'Customer Type' table. But this is where I choose to Aggregate a field rather than expand. You may require a different aggregate measure other than median, dependant on data type:
Expand as Aggregate
The result from my data is below:
Result
Please also see sample.pbix file which I hope can help you with your issue.