SELECT count(*) FROM phone
How many phones are there?
[Schema (values) (types)]: | phone_market |  phone : name (text) , phone_id (text) , memory_in_g (number) , carrier (number) , price (text) | market : market_id (text) , district (text) , num_of_employees (number) , num_of_shops (number) , ranking (text) | phone_market : market_id (text) , phone_id (text) , num_of_stock (number);