CREATE TABLE station (id NUMBER, name CLOB, lat NUMBER, long NUMBER, dock_count NUMBER, city CLOB, installation_date CLOB)
CREATE TABLE status (station_id NUMBER, bikes_available NUMBER, docks_available NUMBER, time CLOB)
CREATE TABLE weather (date CLOB, max_temperature_f NUMBER, mean_temperature_f NUMBER, min_temperature_f NUMBER, max_dew_point_f NUMBER, mean_dew_point_f NUMBER, min_dew_point_f NUMBER, max_humidity NUMBER, mean_humidity NUMBER, min_humidity NUMBER, max_sea_level_pressure_inches NUMBER, mean_sea_level_pressure_inches NUMBER, min_sea_level_pressure_inches NUMBER, max_visibility_miles NUMBER, mean_visibility_miles NUMBER, min_visibility_miles NUMBER, max_wind_speed_mph NUMBER, mean_wind_speed_mph NUMBER, max_gust_speed_mph NUMBER, precipitation_inches NUMBER, cloud_cover NUMBER, events CLOB, wind_dir_degrees NUMBER, zip_code NUMBER)
CREATE TABLE trip (id NUMBER, duration NUMBER, start_date CLOB, start_station_name CLOB, start_station_id NUMBER, end_date CLOB, end_station_name CLOB, end_station_id NUMBER, bike_id NUMBER, subscription_type CLOB, zip_code NUMBER)

How many trips started from Mountain View city and ended at Palo Alto city?
SELECT COUNT(*) FROM station AS T1 JOIN trip AS T2 JOIN station AS T3 JOIN trip AS T4 ON T1.id = T2.start_station_id AND T2.id = T4.id AND T3.id = T4.end_station_id WHERE T1.city = "Mountain View" AND T3.city = "Palo Alto"
SELECT COUNT(*) FROM "station" "T1" JOIN "station" "T3" ON "Palo Alto" = "T3"."city" JOIN "trip" "T4" ON "T3"."id" = "T4"."end_station_id" JOIN "trip" "T2" ON "T1"."id" = "T2"."start_station_id" AND "T2"."id" = "T4"."id" WHERE "Mountain View" = "T1"."city"