CREATE TABLE school_bus (school_id DECIMAL, driver_id DECIMAL, years_working DECIMAL, if_full_time others)
CREATE TABLE driver (driver_id DECIMAL, name TEXT, party TEXT, home_city TEXT, age DECIMAL)
CREATE TABLE school (school_id DECIMAL, grade TEXT, school TEXT, location TEXT, type TEXT)

find the name of driver who is driving the school bus with the longest working history.
SELECT t1.name FROM driver AS t1 JOIN school_bus AS t2 ON t1.driver_id = t2.driver_id ORDER BY years_working DESC LIMIT 1
SELECT "t1"."name" FROM "driver" AS "t1" JOIN "school_bus" AS "t2" ON "t1"."driver_id" = "t2"."driver_id" ORDER BY "years_working" DESC NULLS LAST LIMIT 1