Output Group By 'List' Aggregation to Excel

I am unsure how to output the results of a group by where there is a manually aggregated LIST.

It appears as data type ‘(…)’, and shows up well in KNIME, but I cannot seem to export this successfully to Excel. All the other columns/data types seem to come through fine into Excel.

Any suggestions please?

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Hello @supersharp,

The reason you cannot map it is because Excel does not support that data type. I recommend using the Split Collection Column node to separate the value into multiple columns and then use the Column Aggregator to concatenate into a string. Then you will be able to see the field in the Excel Write (xls) node and map it.

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Regards,
cpadilla

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Or alternatively, use the split collection column node, then an unpivot node to give you a normalised (i.e.: “narrow”) list, with repeating “topic id”. You could then write this out to Excel and use a pivot table to further analyse it or do that in Knime.

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Instead of split and unpivot you can also use the ungroup node

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Or use the concatenate aggregation in the GroupBy node for the column in the first place

Steve

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Thanks for everyone’s input!