Table schema:
CREATE TABLE complaints (staff_id VARCHAR); CREATE TABLE staff (first_name VARCHAR, staff_id VARCHAR)

Question: What is first names of the top 5 staff who have handled the greatest number of complaints?
SQL: SELECT t1.first_name FROM staff AS t1 JOIN complaints AS t2 ON t1.staff_id = t2.staff_id GROUP BY t2.staff_id ORDER BY COUNT(*) LIMIT 5