isMissing... is missing?

KNIME Analytics Platform
1

Just dipping my toes into KNIME, so I’m probably doing something wrong. But I’m trying to translate a formula from Alteryx into KNIME expressions, but I’m bashing my head over the concept of isNull / NOT isNull. From what I can find online, it seems like “isMissing” is what I’m looking for, but it just doesn’t show up as a valid expression in any expression tools I try.

Specifically I’ve tried the ‘Expression’ and ‘Expression Row Filter’ nodes. Is there a reason why I can’t use isMissing?

2

I had the same doubts earlier. Here is what I learned,

IsMissing functions is specially for column expressions(legacy) node.

Syntax : IsMissing($columnname$)

If you want to use Expression node, you can try

$Columnname$ == MISSING for isNull
$Columnname$ != MISSING for !isNull

And i believe Expression row filter uses the same syntax as Expression node. Hope this helps!

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3

Arun is right!
In my expression nodes I use something like

if($[ROW_NUMBER] = COLUMN_COUNT("B") and $["B"] = MISSING, "wow", "")

to catch the last row and test if there is a missing value in Column B.

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