How many companies operate airlines in each airport? | Do you want the result by airport id, or airport name or all airport information? | I would like the results by airport id, please.
SELECT T3.id ,  count ( * )  FROM operate_company AS T1 JOIN flight AS t2 ON T1.id   =   T2.company_id JOIN airport AS T3 ON T2.airport_id   =   T3.id GROUP BY T3.id
companies operate airlines refers to counting unique companies (operate_company) associated with flights; each airport refers to grouping results by airport; result by airport id refers to selecting T3.id (assuming T3 refers to airport table) and grouping by T3.id;