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

How films are produced by each studio?
SELECT studio, COUNT(*) FROM film GROUP BY studio
SELECT "studio", COUNT(*) FROM "film" GROUP BY "studio"