I need to feed a document with new data, so what I was doing was running the workflow, writing the file and opening it after execution, and then copying the rows and pasting it into an existing file. So this is my Q: Is there a way to append new data to an existing excel file?
there should be a simple solution for your problem…
Beside calculating the “new data” you may read the existing Excel file with the help of the Excel File Reader node.
Then you may Concatenate the existing content with the new data with the help of the Concatenate node
At the end you save the new table with old and new data as a xls file. You may even overwrite the existing one.
this is not possible with native KNIME nodes but you can use Python (see here: Adding to an existing Excel File) for example or read data into KNIME as @tommy suggested.
Additionally there is ticket to handle it and have given it +1. (Internal reference: AP-14911)