Using flow variables in node expressions

I am trying to build a workflow to load data files to a database. There files are grouped by date and there are basically the same files to be loaded every day. Some days have tables that others don’t because those tables are only updated weekly. I am trying to parse out the date from the file names and add that date to a column in the list of files before looping through them to import them but I am not finding any nodes that allow me to do this. Can anyone help?

Welcome to the KNIME Forum! To parse out the date from the file name, you can use the String Manipulation node.
Kind regards

I am not explaining myself well I guess. Here is an example. In the Row Filter node I would like to set a pattern expression that is something like this {flow variable} where the flow variable changes each time through a loop. Is this possible?

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Hi @wynkoopc and welcome to the KNIME community forum,

Yes, that’s possible. The String Manipulation (Variable) node can generate the regular expression you need dynamically. That’s what I do in my workflows to generate dynamic expressions to use in other nodes like String Manipulation, Math Formula, Rule Engine and so on.

If you need more help here, it would be great to provide an input example and your desired output. So me or other community members can easily provide you with accurate solutions or even example workflows.



Thank you armingrudd!


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