Context: CREATE TABLE payment (staff_id VARCHAR); CREATE TABLE staff (first_name VARCHAR, last_name VARCHAR, staff_id VARCHAR)
Question: Which staff handled least number of payments? List the full name and the id.
Answer: SELECT T1.first_name, T1.last_name, T1.staff_id FROM staff AS T1 JOIN payment AS T2 ON T1.staff_id = T2.staff_id GROUP BY T1.staff_id ORDER BY COUNT(*) LIMIT 1