Possible Bug in Column Filter

Using Column Filer for excluding a column.
The column name to exclude is controlled by a variable, however, no filtering is performed.

See attached workflow.

Many thankscolumn filter bug.knwf (4.8 KB)


It is because you included column with column name “2” in row filter. Then he leaves it inside.

Column filter node is not an easy node to control by a flow variable. I would use Reference Column Filter node for this purpose. Create your workflow in a way you extract/find column names which you want to exclude (or include) and then use it as a reference for filtering.



Hi Ivan,

Yes, “2” is included in the columns list and excluded by the flow variable.
FMHO, what is expected from the node, in such a case, that it is excluded because “enforce exclusion” is selected.
What you think?

Best Regards.


Hi Moran,

not sure if it is connected to enforce inclusion/exclusion options. In your example if you have checked enforce exclusion then you get all 3 columns as result. If you have checked enforce inclusion you do not get column 3 which is a bit odd.

So maybe it goes like this. You excluded column 3 but then you set it to be controlled by a variable with value 2. But column with name 2 is included so node leaves column 2 inside but as option enforce inclusion is set only 2 column can be in your final result so column 3 is excluded :smiley:


Hi Ivan,
You analysis is almost correct, however, as you can see in the example, it does include all the three columns (and exclude nothing) which is odd.
This is because column “2” is both in the excluded (as a flow variable that override the the column to be excluded) and included (as originally set in the node).
Therefore, it is expected that for column “2” inclusion/exclusion will be according to the “enforce inclusion/exclusion option”. Otherwise, there is no way to set the exclusion list dynamically by a flow variable.

Anyway, meanwhile I am working around this by using a reference column filter instead.

Thank you very much


Good luck!