GroupBy Unique Concatenate with Count

I have a column category of ListingId with 577 unique datasets. Within each of these 577 ListingId datasets are numeric Identifiers (1002, 1017, 3003, etc).

Now I wish to concatenate with counts these numeric identifiers into each of nine Column Categories “QValue” (Q1, Q2, Q3, etc.).

But I cannot get GroupBy, Concatenate with Count to give me the count. I can easily concatenate all the numeric identifiers into each QValue group, but I cannot get the results such as "1002(15), 1017(22), 3003(32), etc.

Where am I going wrong?

I even tried renaming the convoluted “unique concatenate*(unique concatenate)” column naming from the prior analyses incase it was creating a problem, and also saved the output to a Cache incase multiple GroupBy steps were creating a problem. Nothing seems to give me an actual concatenated count of the numeric identifiers combined within the series of QValue groups.


just FYI, here’s my GroupBy settings.

Hi @smithcreed

A solution is to use a Cell Splitter node to split the “unique concatenate” column. And then aggregate them again using the Column Aggregator node, there is an option : Unique concatenate with count. See this example: unique_concat_with_count.knwf (15.5 KB)
Screenshot from 2020-09-30 19-27-59
gr. Hans

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Thank you, I’ll give it a run.

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Hi Hans, here’s my set up. But I simply get a count for unique within the ListingId group–all “1’s”. I need to pull all of those into their respective “QValue” group, then perform the unique concatenate with count. I am still failing at that.

I also then attempted a GroupBy for QValue, but after splitting the column I create a problem of getting repeating values in the column arrays (for example 1017 showing up in many columns with different counts instead of a single count for the QValue.

You can use a Stringmanipulation to replace the spaces and then do what Hans suggested

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Hi @smithcreed

I made some adjustments to my workflow. I added a pivot on the Qvalue column see KNIME_project3.knwf (26.8 KB)


thanks, let me run another try with this. i had experimented with the pivoting earlier, but sometimes it’s a matter of the order of the node functions that makes things come together.

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Wow, crazy little run of nodes, but I think it worked. I need to do some quality checking to make sure I removed any redundant counts.

Thank you very much for the help!

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