# How to combine column data based on rules

**URL:** <https://forum.knime.com/t/how-to-combine-column-data-based-on-rules/21394>\
**Category:** KNIME Analytics Platform\
**Created:** [February 26, 2020, 7:13pm UTC](https://forum.knime.com/t/how-to-combine-column-data-based-on-rules/21394 "2020-02-26T19:13:40Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![watsonchris45](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/w/b3f665/32.png) [@watsonchris45](https://forum.knime.com/u/watsonchris45)\
**Post date:** [February 26, 2020, 7:13pm UTC](https://forum.knime.com/t/how-to-combine-column-data-based-on-rules/21394/1 "2020-02-26T19:13:40Z")

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Hello all. I am trying to combine columns based on a set of rules.  
Example:  
I want to turn this,  
Column. Column A. Column B.  
A. S. R.  
B. S. R.  
C. S. P.  
D. S. P.

Into this,  
Column. Column A. Column B.  
A., B. S. R.  
C., D. S. P.

So if the contents of Culumn A and Column B match, create a comma separated cell for the contents in “Column”

Any help?

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**Author:** ![ScottF](https://forum-cdn.knime.com/user_avatar/forum.knime.com/scottf/32/61316_2.png) [@ScottF](https://forum.knime.com/u/ScottF)\
**Post date:** [February 26, 2020, 7:37pm UTC](https://forum.knime.com/t/how-to-combine-column-data-based-on-rules/21394/2 "2020-02-26T19:37:25Z")

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Hi @watsonchris45 and welcome to the forum.

How about the [GroupBy](https://kni.me/n/5stmXk6zY_ORA4bC) node?

With a table like this:

![2020-02-26 13_35_23-Manually created table - 5_333 - Table Creator](https://forum-cdn.knime.com/uploads/default/original/2X/e/eef588efbe15000dd5e27f8c9e30d6002d16b963.png)

In the GroupBy node configuration, I can group on column 1 and column 2. Then, under the Manual Aggregation tab, set the ID column to have aggregation of type List. Results:

![2020-02-26 13_37_15-Group table - 5_334 - GroupBy](https://forum-cdn.knime.com/uploads/default/original/2X/1/1efd2181cf6c98de7d4f51fcaaea2af69e84a951.png)

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<div class="post-metadata">

**Author:** ![watsonchris45](https://forum-cdn.knime.com/letter_avatar_proxy/v4/letter/w/b3f665/32.png) [@watsonchris45](https://forum.knime.com/u/watsonchris45)\
**Post date:** [February 26, 2020, 8:00pm UTC](https://forum.knime.com/t/how-to-combine-column-data-based-on-rules/21394/3 "2020-02-26T20:00:45Z")

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Worked perfect! Thank you!

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**Author:** ![system](https://forum-cdn.knime.com/uploads/default/original/1X/ab3ccf34482a0329361734a18199390177204f15.png) [@system](https://forum.knime.com/u/system)\
**Post date:** [August 27, 2020, 8:07am UTC](https://forum.knime.com/t/how-to-combine-column-data-based-on-rules/21394/4 "2020-08-27T08:07:25Z")

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