CREATE TABLE film (film_id NUMBER, title CLOB, studio CLOB, director CLOB, gross_in_dollar NUMBER)
CREATE TABLE film_market_estimation (estimation_id NUMBER, low_estimate NUMBER, high_estimate NUMBER, film_id NUMBER, type CLOB, market_id NUMBER, year NUMBER)
CREATE TABLE market (market_id NUMBER, country CLOB, number_cities NUMBER)

Show the studios that have produced films with director 'Nicholas Meyer' and 'Walter Hill'.
SELECT studio FROM film WHERE director = "Nicholas Meyer" INTERSECT SELECT studio FROM film WHERE director = "Walter Hill"
SELECT "studio" FROM "film" WHERE "Nicholas Meyer" = "director" INTERSECT SELECT "studio" FROM "film" WHERE "Walter Hill" = "director"