SELECT rid FROM routes WHERE dst_apid IN (SELECT apid FROM airports WHERE country = 'United States') AND src_apid IN (SELECT apid FROM airports WHERE country = 'United States')
Temukan ID rute yang bandar sumber dan tujuannya berada di Amerika Serikat.
CREATE TABLE routes (rid VARCHAR, dst_apid VARCHAR, src_apid VARCHAR, apid VARCHAR, country VARCHAR); CREATE TABLE airports (rid VARCHAR, dst_apid VARCHAR, src_apid VARCHAR, apid VARCHAR, country VARCHAR)