CREATE TABLE Rooms (roomName VARCHAR2, RoomId VARCHAR2)
CREATE TABLE Reservations (Room VARCHAR2)

Find the most popular room in the hotel. The most popular room is the room that had seen the largest number of reservations.
SELECT T2.roomName FROM Reservations AS T1 JOIN Rooms AS T2 ON T1.Room = T2.RoomId GROUP BY T1.Room ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."roomName" FROM "Reservations" "T1" JOIN "Rooms" "T2" ON "T1"."Room" = "T2"."RoomId" GROUP BY "T1"."Room" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY