CREATE TABLE flight_fare (flight_id INT, fare_id INT)
CREATE TABLE ground_service (city_code TEXT, airport_code TEXT, transport_type TEXT, ground_fare INT)
CREATE TABLE code_description (code VARCHAR, description TEXT)
CREATE TABLE equipment_sequence (aircraft_code_sequence VARCHAR, aircraft_code VARCHAR)
CREATE TABLE food_service (meal_code TEXT, meal_number INT, compartment TEXT, meal_description VARCHAR)
CREATE TABLE flight_leg (flight_id INT, leg_number INT, leg_flight INT)
CREATE TABLE month (month_number INT, month_name TEXT)
CREATE TABLE restriction (restriction_code TEXT, advance_purchase INT, stopovers TEXT, saturday_stay_required TEXT, minimum_stay INT, maximum_stay INT, application TEXT, no_discounts TEXT)
CREATE TABLE compartment_class (compartment VARCHAR, class_type VARCHAR)
CREATE TABLE flight (aircraft_code_sequence TEXT, airline_code VARCHAR, airline_flight TEXT, arrival_time INT, connections INT, departure_time INT, dual_carrier TEXT, flight_days TEXT, flight_id INT, flight_number INT, from_airport VARCHAR, meal_code TEXT, stops INT, time_elapsed INT, to_airport VARCHAR)
CREATE TABLE airport (airport_code VARCHAR, airport_name TEXT, airport_location TEXT, state_code VARCHAR, country_name VARCHAR, time_zone_code VARCHAR, minimum_connect_time INT)
CREATE TABLE time_zone (time_zone_code TEXT, time_zone_name TEXT, hours_from_gmt INT)
CREATE TABLE date_day (month_number INT, day_number INT, year INT, day_name VARCHAR)
CREATE TABLE fare_basis (fare_basis_code TEXT, booking_class TEXT, class_type TEXT, premium TEXT, economy TEXT, discounted TEXT, night TEXT, season TEXT, basis_days TEXT)
CREATE TABLE fare (fare_id INT, from_airport VARCHAR, to_airport VARCHAR, fare_basis_code TEXT, fare_airline TEXT, restriction_code TEXT, one_direction_cost INT, round_trip_cost INT, round_trip_required VARCHAR)
CREATE TABLE city (city_code VARCHAR, city_name VARCHAR, state_code VARCHAR, country_name VARCHAR, time_zone_code VARCHAR)
CREATE TABLE aircraft (aircraft_code VARCHAR, aircraft_description VARCHAR, manufacturer VARCHAR, basic_type VARCHAR, engines INT, propulsion VARCHAR, wide_body VARCHAR, wing_span INT, length INT, weight INT, capacity INT, pay_load INT, cruising_speed INT, range_miles INT, pressurized VARCHAR)
CREATE TABLE dual_carrier (main_airline VARCHAR, low_flight_number INT, high_flight_number INT, dual_airline VARCHAR, service_name TEXT)
CREATE TABLE days (days_code VARCHAR, day_name VARCHAR)
CREATE TABLE state (state_code TEXT, state_name TEXT, country_name TEXT)
CREATE TABLE class_of_service (booking_class VARCHAR, rank INT, class_description TEXT)
CREATE TABLE airline (airline_code VARCHAR, airline_name TEXT, note TEXT)
CREATE TABLE airport_service (city_code VARCHAR, airport_code VARCHAR, miles_distant INT, direction VARCHAR, minutes_distant INT)
CREATE TABLE time_interval (period TEXT, begin_time INT, end_time INT)
CREATE TABLE flight_stop (flight_id INT, stop_number INT, stop_days TEXT, stop_airport TEXT, arrival_time INT, arrival_airline TEXT, arrival_flight_number INT, departure_time INT, departure_airline TEXT, departure_flight_number INT, stop_time INT)

is there one airline that flies from BURBANK to MILWAUKEE milwaukee to ST. LOUIS and from ST. LOUIS to BURBANK
SELECT DISTINCT airline_code FROM airline WHERE ((airline_code IN (SELECT FLIGHTalias1.airline_code FROM flight AS FLIGHTalias1 WHERE (FLIGHTalias1.from_airport IN (SELECT AIRPORT_SERVICEalias2.airport_code FROM airport_service AS AIRPORT_SERVICEalias2 WHERE AIRPORT_SERVICEalias2.city_code IN (SELECT CITYalias2.city_code FROM city AS CITYalias2 WHERE CITYalias2.city_name = 'ST. LOUIS')) AND FLIGHTalias1.to_airport IN (SELECT AIRPORT_SERVICEalias3.airport_code FROM airport_service AS AIRPORT_SERVICEalias3 WHERE AIRPORT_SERVICEalias3.city_code IN (SELECT CITYalias3.city_code FROM city AS CITYalias3 WHERE CITYalias3.city_name = 'BURBANK')))) AND airline_code IN (SELECT FLIGHTalias2.airline_code FROM flight AS FLIGHTalias2 WHERE (FLIGHTalias2.from_airport IN (SELECT AIRPORT_SERVICEalias4.airport_code FROM airport_service AS AIRPORT_SERVICEalias4 WHERE AIRPORT_SERVICEalias4.city_code IN (SELECT CITYalias4.city_code FROM city AS CITYalias4 WHERE CITYalias4.city_name = 'BURBANK')) AND FLIGHTalias2.to_airport IN (SELECT AIRPORT_SERVICEalias5.airport_code FROM airport_service AS AIRPORT_SERVICEalias5 WHERE AIRPORT_SERVICEalias5.city_code IN (SELECT CITYalias5.city_code FROM city AS CITYalias5 WHERE CITYalias5.city_name = 'MILWAUKEE'))))) AND airline_code IN (SELECT FLIGHTalias0.airline_code FROM flight AS FLIGHTalias0 WHERE (FLIGHTalias0.from_airport IN (SELECT AIRPORT_SERVICEalias0.airport_code FROM airport_service AS AIRPORT_SERVICEalias0 WHERE AIRPORT_SERVICEalias0.city_code IN (SELECT CITYalias0.city_code FROM city AS CITYalias0 WHERE CITYalias0.city_name = 'MILWAUKEE')) AND FLIGHTalias0.to_airport IN (SELECT AIRPORT_SERVICEalias1.airport_code FROM airport_service AS AIRPORT_SERVICEalias1 WHERE AIRPORT_SERVICEalias1.city_code IN (SELECT CITYalias1.city_code FROM city AS CITYalias1 WHERE CITYalias1.city_name = 'ST. LOUIS')))))
WITH "_u_10" AS (SELECT "CITYalias0"."city_code" FROM "city" AS "CITYalias0" WHERE "CITYalias0"."city_name" = 'MILWAUKEE' GROUP BY "city_code"), "_u_11" AS (SELECT "AIRPORT_SERVICEalias0"."airport_code" FROM "airport_service" AS "AIRPORT_SERVICEalias0" LEFT JOIN "_u_10" AS "_u_10" ON "AIRPORT_SERVICEalias0"."city_code" = "_u_10"."" WHERE NOT "_u_10"."" IS NULL GROUP BY "airport_code"), "_u_12" AS (SELECT "CITYalias1"."city_code" FROM "city" AS "CITYalias1" WHERE "CITYalias1"."city_name" = 'ST. LOUIS' GROUP BY "city_code"), "_u_13" AS (SELECT "AIRPORT_SERVICEalias1"."airport_code" FROM "airport_service" AS "AIRPORT_SERVICEalias1" LEFT JOIN "_u_12" AS "_u_12" ON "AIRPORT_SERVICEalias1"."city_code" = "_u_12"."" WHERE NOT "_u_12"."" IS NULL GROUP BY "airport_code"), "_u_14" AS (SELECT "FLIGHTalias0"."airline_code" FROM "flight" AS "FLIGHTalias0" LEFT JOIN "_u_11" AS "_u_11" ON "FLIGHTalias0"."from_airport" = "_u_11"."" LEFT JOIN "_u_13" AS "_u_13" ON "FLIGHTalias0"."to_airport" = "_u_13"."" WHERE NOT "_u_11"."" IS NULL AND NOT "_u_13"."" IS NULL GROUP BY "airline_code"), "_u_0" AS (SELECT "CITYalias2"."city_code" FROM "city" AS "CITYalias2" WHERE "CITYalias2"."city_name" = 'ST. LOUIS' GROUP BY "city_code"), "_u_1" AS (SELECT "AIRPORT_SERVICEalias2"."airport_code" FROM "airport_service" AS "AIRPORT_SERVICEalias2" LEFT JOIN "_u_0" AS "_u_0" ON "AIRPORT_SERVICEalias2"."city_code" = "_u_0"."" WHERE NOT "_u_0"."" IS NULL GROUP BY "airport_code"), "_u_2" AS (SELECT "CITYalias3"."city_code" FROM "city" AS "CITYalias3" WHERE "CITYalias3"."city_name" = 'BURBANK' GROUP BY "city_code"), "_u_3" AS (SELECT "AIRPORT_SERVICEalias3"."airport_code" FROM "airport_service" AS "AIRPORT_SERVICEalias3" LEFT JOIN "_u_2" AS "_u_2" ON "AIRPORT_SERVICEalias3"."city_code" = "_u_2"."" WHERE NOT "_u_2"."" IS NULL GROUP BY "airport_code"), "_u_4" AS (SELECT "FLIGHTalias1"."airline_code" FROM "flight" AS "FLIGHTalias1" LEFT JOIN "_u_1" AS "_u_1" ON "FLIGHTalias1"."from_airport" = "_u_1"."" LEFT JOIN "_u_3" AS "_u_3" ON "FLIGHTalias1"."to_airport" = "_u_3"."" WHERE NOT "_u_1"."" IS NULL AND NOT "_u_3"."" IS NULL GROUP BY "airline_code"), "_u_5" AS (SELECT "CITYalias4"."city_code" FROM "city" AS "CITYalias4" WHERE "CITYalias4"."city_name" = 'BURBANK' GROUP BY "city_code"), "_u_6" AS (SELECT "AIRPORT_SERVICEalias4"."airport_code" FROM "airport_service" AS "AIRPORT_SERVICEalias4" LEFT JOIN "_u_5" AS "_u_5" ON "AIRPORT_SERVICEalias4"."city_code" = "_u_5"."" WHERE NOT "_u_5"."" IS NULL GROUP BY "airport_code"), "_u_7" AS (SELECT "CITYalias5"."city_code" FROM "city" AS "CITYalias5" WHERE "CITYalias5"."city_name" = 'MILWAUKEE' GROUP BY "city_code"), "_u_8" AS (SELECT "AIRPORT_SERVICEalias5"."airport_code" FROM "airport_service" AS "AIRPORT_SERVICEalias5" LEFT JOIN "_u_7" AS "_u_7" ON "AIRPORT_SERVICEalias5"."city_code" = "_u_7"."" WHERE NOT "_u_7"."" IS NULL GROUP BY "airport_code"), "_u_9" AS (SELECT "FLIGHTalias2"."airline_code" FROM "flight" AS "FLIGHTalias2" LEFT JOIN "_u_6" AS "_u_6" ON "FLIGHTalias2"."from_airport" = "_u_6"."" LEFT JOIN "_u_8" AS "_u_8" ON "FLIGHTalias2"."to_airport" = "_u_8"."" WHERE NOT "_u_6"."" IS NULL AND NOT "_u_8"."" IS NULL GROUP BY "airline_code") SELECT DISTINCT "airline_code" FROM "airline" LEFT JOIN "_u_14" AS "_u_14" ON "_u_14"."" = "airline_code" LEFT JOIN "_u_4" AS "_u_4" ON "_u_4"."" = "airline_code" LEFT JOIN "_u_9" AS "_u_9" ON "_u_9"."" = "airline_code" WHERE NOT "_u_14"."" IS NULL AND NOT "_u_4"."" IS NULL AND NOT "_u_9"."" IS NULL