Table schema:
CREATE TABLE Staff_Department_Assignments (staff_id VARCHAR); CREATE TABLE staff (staff_id VARCHAR, staff_name VARCHAR)

Question: Find the id and name of the staff who has been assigned for the shortest period.
SQL: SELECT T1.staff_id, T1.staff_name FROM staff AS T1 JOIN Staff_Department_Assignments AS T2 ON T1.staff_id = T2.staff_id ORDER BY date_assigned_to - date_assigned_from LIMIT 1