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mh20221111's avatar
mh20221111
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1 year ago
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Issues with Expanding Columns in Power BI Dataflows When Importing JSON Files

When importing a JSON file in Power BI dataflows, sometimes the expand button does not appear in the upper left corner of the column, preventing expansion. This situation often occurs when the top of...
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  • rohit1991's avatar
    rohit1991
    1 year ago

    Hi mh20221111 ,
    When importing JSON files into Power BI dataflows, the expand icon may not appear if the column doesn't contain recognizable list or record structures in the initial rows—often due to blank values or inconsistent formatting. In such cases, Power BI doesn't infer a structured type and therefore doesn't offer the expand option. 

     

    A common workaround is to first filter out the null or blank rows so Power BI can detect the underlying structure, after which the expand button typically becomes available. If that doesn’t work, using the Advanced Editor is indeed a viable method—you can manually modify the M code to access and expand the nested records or lists. While it's not the only solution, it's often the most reliable in these edge cases.

     
Anonymous's avatar
Anonymous
Not applicable
1 year ago

Hi mh20221111 ,
Thank you for reaching out to us on  Microsoft Fabric Community Forum!

This issue usually occurs when the top rows in the JSON column are null or not structured as records or lists, which prevents Power Query from displaying the expand icon. As a work around , try filtering out the null or unstructured rows so that the first visible row contains a record or list, this may trigger the expand icon to appear. If that does not help, you may use the Advanced Editor to manually expand the column using M code like using below:       

          Table.ExpandRecordColumn(Source, "YourColumn", {"Field1", "Field2"}).

Hope this helps.If this answer resolve your issue,consider accepting it as solution.

Regards,
Pallavi.