Forum Discussion
Nested tables causing refresh issues in PowerBI Service
When your group by includes "all rows" that will carry these columns around. Instead of group by consider using Table.SelectColumns to only pick the columns you need.
Power Query can handle all kinds of data types (including nested types) but at the end of a query (especially if you want to load that into Power BI) all columns must have one of the allowed types (plus variant, but that is not desirable)
No other column types are permitted. Either exclude the table and value types, or convert/flatten them into permitted column types.
Thanks a lot for the response!
Yep, thats a good point. Do you know how I can exclude them? For some reason I can't just remove the columns, as it still returns the same error.
You probably didn't catch them all. Use Value.Is to validate across columns.
Apologies if something is going over my head, and I appreciate your patience. However, I'm not sure its possible that I could have not caught them all, as one example where the error is appearing leaves two perfectly valid seeming columns:
This is the step immediately after I have connected to the PostgreSQL database and imported the table. It includes the "Value" column and a bunch of "Table" columns that appear to have been automatically generated. I then do a "group by" query that leaves me with just two columns, both seemingly valid:
I nevertheless receive an error message in PBI Service pointing to this table, saying that it cannot find the "Value" column from the first image.
When your group by includes "all rows" that will carry these columns around. Instead of group by consider using Table.SelectColumns to only pick the columns you need.