Which professor taught the least amount of courses?
professor refers to taughtBy.p_id; least amount of courses refers to min(count(course_id))
SELECT p_id FROM taughtBy GROUP BY p_id ORDER BY COUNT(course_id) ASC LIMIT 1
database name:db_id computer_student
course table course Cols: course id dtype integer, course level dtype text, 
person table person Cols: person ID dtype integer, professor dtype integer, student dtype integer, has position dtype text, in phase dtype text, years in program dtype text, 
advisedBy table advisedBy Cols: person id dtype integer, person id dummy dtype integer, 
taughtBy table taughtBy Cols: course ID dtype integer, person ID dtype integer, 
