39 - 电影评分 (selectu.name as resultsfromMovieRating m left join Users u on m.user_id=u.user_id GROUP BYm.user_idorder by count(*) desc,u.name asc limit 1)union all(selectm1.title as results
38 - 换座位 -- 方法一select(casewhen id%2=1 and id=(select max(id) from seat) then idwhen id%2=0 then id-1else id+1end) as id, studentfromseatorder byid;-- 方法二selectif(id%2=0,id-1,if(id=(select max(i