Table schema:
CREATE TABLE students (student_details VARCHAR, student_id VARCHAR); CREATE TABLE student_course_registrations (student_id VARCHAR)

Question: What is detail of the student who registered the most number of courses?
SQL: SELECT T1.student_details FROM students AS T1 JOIN student_course_registrations AS T2 ON T1.student_id = T2.student_id GROUP BY T1.student_id ORDER BY COUNT(*) DESC LIMIT 1