I'm using a CASE WHEN expression in the field calculator on an existing field which already contains information. The expression is comparing two fields. If these fields match, the result should be 0. It looks something like this
CASE WHEN "TD_sum" = "Qup THEN" '0' END. The field I'm editing already contains values which should stay the same if the CASE isn't true. So how do I alter the expression so it only calculates the matching fields? Is it possible to add
ELSE? What do i write as the output?
I know that I can simply select the matching fields with select features and then calculate them, but maybe this calculation will be necessary for a model and I want as little individual steps as possible.