Question: Find the most popular room in the hotel. The most popular room is the room that had seen the largest number of reservations.
Schema: create table reservations (room varchar, PRIMARY KEY (room)); create table rooms (roomname varchar, roomid varchar, PRIMARY KEY (roomname))
SQL: 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