CREATE TABLE table_63849 ("Airline" TEXT, "IATA" TEXT, "ICAO" TEXT, "Callsign" TEXT, "Commenced operations" FLOAT)

Which Callsign has an IATA of tr?
SELECT "Callsign" FROM table_63849 WHERE "IATA" = 'tr'
SELECT "Callsign" FROM "table_63849" WHERE "IATA" = 'tr'