Forum Discussion
Super UserUsing DQ dataset as destination page for drill through
Hi PBI Gurus,
I am having 2 queries, Q1 is Import and Q2 is DQ. Q2 has approx 2M recs which is supposed to actually billions of records but I filtered it.
I also created a BridgeTable query with Key data and using the fields in key for drill through which is Asset and Date.
Now When I am trying to drill through from line chart created form Q1 to to detail page created from Q2 it throws below error and I am not able to show the details of data.
We couldn't fold the expression to the data source. Please try a simpler expression.
Help is apprcieted here please
Hi srlabhe
Drillthrough from an Import visual into a DirectQuery detail page fails when the filters cannot be folded to the DQ source. In your setup the drillthrough filter likely travels through a bridge or a calculated column/date hierarchy, so Power BI can’t translate it to a simple SQL WHERE and you get ‘We couldn’t fold the expression…’.
What usually fixes it:
• Make the drillthrough fields raw, foldable columns that also exist in the DQ source (e.g., AssetId and DateKey/Date – no Auto Date/Time, no calculated columns).
• Put your dimension tables in Dual mode and use those columns for drillthrough so the filter can fold to DQ.
• Avoid complex filters on the detail page (TopN/Contains/custom visuals). Keep equality filters only.
• Keep the detail page visuals sourced from DQ tables only.
• Ensure clean relationships and integer surrogate keys.If this post helps, then please consider Accepting it as the solution to help the other members find it more quickly
6 Replies
- Ritaf1983
Hi srlabhe
Drillthrough from an Import visual into a DirectQuery detail page fails when the filters cannot be folded to the DQ source. In your setup the drillthrough filter likely travels through a bridge or a calculated column/date hierarchy, so Power BI can’t translate it to a simple SQL WHERE and you get ‘We couldn’t fold the expression…’.
What usually fixes it:
• Make the drillthrough fields raw, foldable columns that also exist in the DQ source (e.g., AssetId and DateKey/Date – no Auto Date/Time, no calculated columns).
• Put your dimension tables in Dual mode and use those columns for drillthrough so the filter can fold to DQ.
• Avoid complex filters on the detail page (TopN/Contains/custom visuals). Keep equality filters only.
• Keep the detail page visuals sourced from DQ tables only.
• Ensure clean relationships and integer surrogate keys.If this post helps, then please consider Accepting it as the solution to help the other members find it more quickly
- Shahid12523
Community Champion
Drill-through from Import → DirectQuery often fails because filters can’t be folded into SQL.
Fix options:
Use same mode for both tables (both Import or both DQ).
Ensure drill-through fields (Asset, Date) are native columns with same datatype in both.
Try Composite Model so Import + DQ work together.
If still failing → simulate drill-through with slicers/bookmarks instead of native drill-through.
- MohamedFowzan1
Hi srlabhe
Next Steps would be:
- If possible have both your tables as DQ- Try out composite model
- Finally, make sure to avoid transformations in Power Query steps that may break folding and in Power Query, right-click on steps and check if “View Native Query” is enabled to confirm folding.
v-achippaCommunity Support
Hi srlabhe,
Thank you for reaching out to Microsoft Fabric Community.
Thank you Ritaf1983, Shahid12523, MohamedFowzan1 for the prompt response.
As we haven’t heard back from you, we wanted to kindly follow up to check if the solution provided by the user's for the issue worked? or let us know if you need any further assistance.
Thanks and regards,
Anjan Kumar Chippa
