How to detect empty field

[marieclaire]

Hello everybody,

I need to detect empty fields in the 2nd column.

I tried to use

if(len(trim([Id Tool]))=0,'undefined',[Id Tool]) as Id_Tool2

But it does not work.

Anybody can help ?

Thank you !

[marieclaire]

Thank you Tresesco. I finally managed to make it work with a new dataset.