Renamed key shows us as undefined at further down the work flow

Describe the problem/error/question


I have renamed a key but after that in the work flow it shows up as undefined, despite it is visible in the scheme of data.

I particulary use it in and IF node at this case.

What is the error message (if any)?

Please share your workflow

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)

Share the output returned by the last node

Information on your n8n setup

  • n8n version:
  • Database (default: SQLite):
  • n8n EXECUTIONS_PROCESS setting (default: own, main):
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seem to be a bug with a merge node.

So if there is a rename key in front of merger/apend. it does not recognise the renamed key as a declared varibale

Hi @rhovath94 :wave: That’s an interesting find - can you share your workflow where this is happening with some sample data that can be reproduced? I’d like to look closer at this one :eyes: Can you also share what version of n8n you’re using?

0.236.3 version, running in a docker container.

Try the last IF , the renmaed key is not recognised by that.

Hey @rhovath94,

I have just ran your workflow and the first item doesn’t have a value for RenamedKey so it is correctly undefined, The second item does have the key set but it doesn’t have the filter field set which you are using for the If condition.

If you change to the Table view it will give you an idea of what has happened.

ok that might be the case with the sample data that i ve tried to enter.

But why is it happening with me live data set? every item has a value here

Hey @rhovath94,

There are 115 items there, As a test can you add an If node before that and do something like If building name is not empty and see if that shows anything.

it does work that and shows some up.
Might be the merge node not functioning properly or i am using it wrongly.

at one branch i have 37element other branch 78 → merge and append becomes 115 as shown on the previous picture. and than i would like to compare this data with an IF but the "building name"shows up as undefined

Hey @rhovath94,

When you added the if did it remove any items or did all 115 move forward? The append doesn’t actually merge the data as such so if one of the inputs doesn’t have that field it won’t add it for that you would need to use one of the combine options.

it did removes/devides the items correctly.
I would exactly want to compare that 2 data set. like the “‘building name’” key comapered to and other key called “'ëntity name”’ with a IF/contains method.

Do you have any suggestions how to do this?

Hey @rhovath94,

I guess it would depend on what it is you are tyring to do in the flow, Are you trying to compare one item against all of the items in the other dataset… Are you planning to merge the 2 records or ignore anything doesn’t match?

i am trying to find matching pairs in the 2data set. a match would be that one item containes part of a string of the other item.

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