Task: Text to Code
Input (English): SQL: SELECT T1.name FROM Reviewer AS T1 WHERE T1.rID NOT IN ( SELECT T2.director FROM Movie AS T2 WHERE T2.title = "null" )
Feedback: Remove step 2 , make sure reviewer id does not equals null , and at least made one movie .
Output (English): SELECT director FROM Movie WHERE director != "null" GROUP BY director HAVING count(*)  =  1