How to add a column by matching data from two tables

Hi Guys,

I am new to Knime and I need your help with a flow. I have two tables.

kvp A/F
27 Mo/Rh
29 Rh/Rh
27 Mo/Rh

kvp Mo/Mo Mo/Rh Rh/Rh
22 0.1 0.2 0.2
23 0.2 0.3 0.4

27 0.8 0.5 0.5
28 0.9 0.4 0.6
29 0.9 0.9 1

I’d like to append a new column to the first table with values by matching data with second table. Is there an easy way to obtain this result?

Resultant table
kvp A/F HVL
27 Mo/Rh 0.5
29 Rh/Rh 1
27 Mo/Rh 0.5

Thank you so much for your help!

Hello @milkyway,

welcome to KNIME Community!

Go with Unpivoting node on table two to get all Mo/Mo, Mo/Rh, Rh/Rh values in one column followed by joining operation where you’ll use Joiner or Joiner (Labs) node.


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Thank you @ipazin for the reply.
I am really not sure how to configure unpivot node and joiner node. It seems doesn’t work.
It does not associate the value of kvp and A/F to the correspondent value in the table2

Any other help please?

Hello @milkyway,

seems your unpivoting node configuration is not correct. In it Mo/Mo, Mo/Rh and Rh/Rh columns are value columns and Kvp column is not (should be included in Retained columns). Then in Joiner you can match records based on Kvp vs Kvp columns and Column Names vs A/F column.


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Thank you so much @ipazin!!!


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