SELECT student_id FROM student_course_registrations GROUP BY student_id ORDER BY count(*) LIMIT 1
what is id of students who registered some courses but the least number of courses in these students?
SELECT student_id FROM student_course_registrations GROUP BY student_id ORDER BY count ( * ) LIMIT 1
select student_id from student_course_registrations group by student_id order by count ( * ) limit value
what is id of students who registered some courses but the least number of courses in these students ?