Forum Discussion
How to transform data from different databases with different security and schemes?
Hi AlexNL,
Thank you for reaching out in Microsoft Community Forum.
You're right: currently, Power BI doesn't support combining tables from different sources (like UNION) directly in Power Query within a composite model. While there are some workarounds (like using DAX or external views), there's no true "Power BI only" solution for this at the moment.
This is a great feature idea, and I’d definitely recommend submitting it on the https://community.fabric.microsoft.com/t5/Ideas/ct-p/PBI_Comm_Ideas - it's feedback like this that helps drive improvements.
Please continue using Microsoft Community Forum.If you found this post helpful, please consider marking it as "Accept as Solution" and give it a 'Kudos' to help others find it more easily.
Regards,
Pavan.
You can with table.union() but all the it will break query folding. You will need to investigate the privacy levels set on each source.
I checked. Unfortunately it does not have any effect.
Hi AlexNL,
Thanks for reaching out in Microsoft Community Forum.
Since the privacy levels check didn’t resolve the issue, please follow below steps to resolve the error;
1.Please Check Query Folding using below steps;
In Power Query, right-click on the steps and see if "View Native Query" is available. If not, query folding is being broken at that step. You can also enable Power Query diagnostics to help identify where folding breaks.2.Load each source table separately into staging queries and then try to combine them later in Power BI. This can sometimes help avoid query folding issues.
3.Please create a SQL view or stored procedure on the database side to perform the UNION before the data is brought into Power BI. This ensures better performance and avoids the folding problem.
Please continue using Microsoft community forum.
If you found this post helpful, please consider marking it as "Accept as Solution" and give it a 'Kudos'. if it was helpful. help other members find it more easily.
Regards,
Pavan.Thank you for answer. I understand answer 2 and 3, but I am looking for a Power BI only solution. I am afraid it is not possible. To be sure I made a simple picture just to be sure you understand the question. THANK YOU.
Hi AlexNL,
Thanks for reaching out in Microsoft Community Forum.
Please follow below to resolve the error;
1.If Power Query doesn’t support UNION, you can create a new table in Power BI using DAX:
CombinedTable = UNION('Table1', 'Table2')2.If the data sources are cloud-based, using Power BI Dataflows might allow pre-aggregation before the model loads.
Please continue using Microsoft community forum.
If you found this post helpful, please consider marking it as "Accept as Solution" and give it a 'Kudos'. if it was helpful. help other members find it more easily.
Regards,
Pavan.