Sum of rows


I am looking how to add values of some rows in order to reduce the row’s number.

For example:

I want to combine the rows 26+28+30+32 in one and to rename it.

Below is my table…

Thank you

Hi Angela_Dru,

one way might be selecting the rows you want to aggregate (rule-based rule engine to identify categories + row splitter to separate rows to be aggregated) and use a GroupBy node to sum the values. Then concatenate results.


Thank you @lelloba but your answer is not very clair for me…
Should I use first rule engine node? If yes how to select the rows? I see only columns…

Try this: Sum of rows – KNIME Hub

Is it working for you? :slight_smile:

How you managed column expression? Have no experience with this node…
how to assign the same number to rows…
a little bit tricky my post

In my solution, column expression is empty. It just creates a new column named “group”.
If you need to understand how to use it, I suggest you watch this video :slight_smile:


You advised to assign the same number to rows ? How is possible?

I have assigned the same number to rows inside the Table Editor node.

If you double click on a cell you can edit it - just like in Excel.

Press enter to save the edited cell and when you close the window make sure to click on Apply as new default.


Thank you, so first I have to create an additional column like your”group”

Exactly! First create, then populate :slight_smile:

Thanks, I managed

It’s a little “monkey work” because my data set has 400 rows…

but it’s an option anyway

I saw that there should be some kind of hierarchy inside the activity column.
Maybe you can just consider level 1 (eg Personal care activities) instead of sleeping, grooming and others. In this case, filter all level 2 activities and keep the main level (personal care activities, eating and drinking, household activities, etc.).


Any ideas how to filter 2 level of activities?

I can use your method with Table editor, but it’s the same consuming of time.

As you can see, there is a certain number of spaces before a general category and a different number of spaces before the second-order category.

Count the number of spaces before the second-order category. Then go back here Sum of rows – KNIME Hub and inside the pattern cell of the Row Splitter node insert the number of spaces for the second-order category and an asterisk. Leave everything else as it is in the image below.


Brilliant idea but I have no result
I tried till 6 spaces and no changes

Hi Angela,

Could you please share some data?


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