Multiple merge / join


I would like to merge or join 12 tables. Do you know how I could do that (I would like to avoid using a lot of concatenate nodes.)? Thank you for your help!

Hi @Elsa_Knime2022

On the Concatenate node, click on the three dots in the lower left corner and add an input. You can then add the 12 ports and connect all your tables to it.



I had not considered that, but that’s a great idea.

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Thank you! Do you know how I can join 12 tables in one node in KNIME, like in SPSS? the rules for joining are always the same

I want to join this files all together (We can’t see all the nodes in my screenshot) . Thank you for your help!

Have you tried adding the ports to the Concatenate node like I mentioned previously and connect all the files?

yes for one part of my stream :smiley: Know I looking for a solution to join multiple table ( same rules of joining)

Either write the tables to database and do it using SQL statement then (in memory DB could be used depending on your dataset size) or script it. The joiner in KNIME only supports 2 input ports.

What about joining inside a recursive loop? Perhaps using the case switch to trigger different file reads per iteration, of they can all use the same file reader node the input could just be the file locations?

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