switching workflow

[mosmel]

Hello guys,

is there a node on knime, if the value of a column X is not null, it executes the node “Excel Writer” to generate the Output file, without running the rest of the workflow.
Otherwise (if the value of a column X is null) it continues the workflow execution without generating the Excel file.
I found the “Switch” node, but I don’t know how to put my condition with this node.

Thanks in advance

[Daniel_Weikert]

you could use a rule engine node to check your condition and return 0 or 1, convert the output to a variable and then use the variable to choose the port of the switch node dynamically.
br

[mlauber71]

@mosmel you could try and create a switch with flow variables:

How can I avoid having to open and close a database connection twice when working with a sub-workflow that is only called when a certain condition is met?

@MgntMoe I still think you would have to think about your approach. I built an example where in a loop at every iteration there would be a check if in the chunk there would be a row with fault=1. In this case, the faulty lines would be exported to a separate sheet in an Excel file. Otherwise, just the number of fault lines would be shipped. Maybe you can take a look. It also uses SQLite as a sample database. [image] kn_example_switch_case_store_file_sql.knwf (158.4 KB)

[rfeigel]

I developed this workflow with a switch for a Knimer who wanted to either write an Excel file, print a plot or both. It should be pretty easy to modify for your case.

Preferential Workflow Control Auto – rfeigel