Updating an Excel file in Knime

KNIME Analytics Platform
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Hi All, am new to Knime and currently using it for a project. I have a workflow that reads excel files and saves to a database, However, I would like the database to have only only new data from the excel file which is updated regularly. Is there a node that could help me to achieve this?

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Hi @michael_o and welcome to the community!

(I just deleted your other post in development to keep things clean)

You can use the DB Merge node as suggested in this topic - there are also some example workflows linked there.

Cheers,
Lukas

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@michael_o in addition to what @LukasS suggested you might want to take a look at this thread about UPDATE and MERGE. I tried to construct an example where new data gets entered into a database in several loops.

From what I understand you might have to clearly define what your scenario is and what you want to do with your data.

  • update existing IDs with new data from all or several lines of your Excel files
  • insert new data into the database

or both? Or do you not want existing data to be altered?

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Thank you, for your reply. My aim is to have the updated and recent data added to my database. My data is read from a URL which is updated frequently. With my current workflow, I only have stale data with no updates in my db.

For instance. I have 4 data rows in my db. By next week, checking the csv files from the URL shows that the file now has additional 2 data rows but this will not be updated in my DB unless I manually reset my nodes. I hope this explains my problem.

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@michael_o to be honst I still do not know what you want the system to do. Maybe you could take a look at these two examples and see if you can use the approach or you might provide us with a sample workflow or data that would represent your challenge

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If you want your workflow to run automatically, you’ll need KNIME Server. In KNIME AP you’ll have to manually reset and re-execute the nodes.
There’re workarounds though, see this post for more info:

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