คุณช่วยหาค่าโดยสารที่ถูกที่สุดจากบอสตันไปซานฟรานซิสโกให้หน่อยได้ไหม ไม่จำเป็นต้องใช้ตารางทั้งหมด
could you find me the cheapest fare from BOSTON to SAN FRANCISCOIt is not neccessary to use all the tables.
 dual_carrier:  main_airline [ varchar]  low_flight_number [ int]  high_flight_number [ int]  dual_airline [ varchar]  service_name [ text] 
SELECT DISTINCT fare.fare_id FROM airport_service AS AIRPORT_SERVICE_0, airport_service AS AIRPORT_SERVICE_1, city AS CITY_0, city AS CITY_1, fare, flight, flight_fare WHERE CITY_0.city_code = AIRPORT_SERVICE_0.city_code AND CITY_0.city_name = 'BOSTON' AND CITY_1.city_code = AIRPORT_SERVICE_1.city_code AND CITY_1.city_name = 'SAN FRANCISCO' AND fare.one_direction_cost = (SELECT MIN(FAREalias1.one_direction_cost) FROM airport_service AS AIRPORT_SERVICEalias2, airport_service AS AIRPORT_SERVICEalias3, city AS CITYalias2, city AS CITYalias3, fare AS FAREalias1, flight AS FLIGHTalias1, flight_fare AS FLIGHT_FAREalias1 WHERE CITYalias2.city_code = AIRPORT_SERVICEalias2.city_code AND CITYalias2.city_name = 'BOSTON' AND CITYalias3.city_code = AIRPORT_SERVICEalias3.city_code AND CITYalias3.city_name = 'SAN FRANCISCO' AND FLIGHT_FAREalias1.fare_id = FAREalias1.fare_id AND FLIGHTalias1.flight_id = FLIGHT_FAREalias1.flight_id AND FLIGHTalias1.from_airport = AIRPORT_SERVICEalias2.airport_code AND FLIGHTalias1.to_airport = AIRPORT_SERVICEalias3.airport_code) AND flight_fare.fare_id = fare.fare_id AND flight.flight_id = flight_fare.flight_id AND flight.from_airport = AIRPORT_SERVICE_0.airport_code AND flight.to_airport = AIRPORT_SERVICE_1.airport_code