CREATE TABLE AIRLINES (Airline VARCHAR, uid VARCHAR); CREATE TABLE FLIGHTS (Airline VARCHAR, SourceAirport VARCHAR)
Find all airlines that have flights from both airports 'APG' and 'CVO'.
SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid = T2.Airline WHERE T2.SourceAirport = "APG" INTERSECT SELECT T1.Airline FROM AIRLINES AS T1 JOIN FLIGHTS AS T2 ON T1.uid = T2.Airline WHERE T2.SourceAirport = "CVO"