CREATE TABLE phone_market (market_id NUMBER, phone_id CLOB, num_of_stock NUMBER)
CREATE TABLE phone (name CLOB, phone_id NUMBER, memory_in_g NUMBER, carrier CLOB, price NUMBER)
CREATE TABLE market (market_id NUMBER, district CLOB, num_of_employees NUMBER, num_of_shops NUMBER, ranking NUMBER)

Show different carriers of phones together with the number of phones with each carrier.
SELECT carrier, COUNT(*) FROM phone GROUP BY carrier
SELECT "carrier", COUNT(*) FROM "phone" GROUP BY "carrier"