I need to stablish some constraints in QGIS form. I tryed some expressions but didn’t work.
In fact what i looking for is to constraint the values in a field based in the value of another field.
If field X = 1, and if field Y > 0, i need a message or something like that who say, ‘the value of Y have to be 0’

I tryed with the expression CASE WHEN “x” = ‘1’ THEN “Y” = ‘0’ END in the value by defaut but didn’t work