Bug in Ungroup node

Note that if you have a workflow setup with the Ungroup node, configure it etc for your data, and it all works fine.

If your workflow is then changed to give an empty table, such that when it enters the Ungroup node there is no data, although the Ungroup node proceeds through fine warning of an empty table, when you come to save the workflow in this state it gives some unusual error messages; "

ERROR Ungroup CODING PROBLEM saveInternals() should only cause IOException.

ERROR Ungroup Unable to save internals: <no details available>"



Hi Simon,

thanks a lot for reporting the problem. I could reproduce it and will fix it for the next KNIME release. The error occurs if you have enabled the hilite translation and the node returns an empty data table.

By the way the ungroup node will support the ungrouping of multiple columns with the next release.




Thanks for the update tobias.

that makes sense as I had a hilite filter node prior to this Ungroup node as I'm using it for hilited rows.

being able to I group multiple columns will be a very handy feature. I look forward to it.



The UnGroup node will support multiple columns with KNIME 2.8, going to be released this month.

I used "groupby" and then "ungroup" for a table. There is no column options for "ungroup". So no expected ungrouped table generated. The error mesage read:

WARN      Ungroup     No ungroup column selected. Node returns input table.

The output table from "groupby" looks fine. Is this a bug?

Please discard the above comment. In order to use "ungroup", the "groupby" need to use list for aggragation.