Tableau Conditional Count Distinct

Question

This is a snapshot of the data pulled into Tableau: 

Success Count is defined as if [Task Status Cal]="Success" then [Wo_ID]

The formula for [Success Count] was:

IF [Task Status Cal] = "Success" then STR([Wo Id])

end

Tableau considered this formula to be valid.

I am not sure why the result was null in cases where the above condition was true. 

Answer 1

Use the below line to fix the problem:

 countd(IF [Task Status Cal] = "Success" THEN [Wo Id] END)