某城市开了一家新的电影院,吸引了很多人过来看电影。该电影院特别注意用户体验,专门有个 LED显示板做电影推荐,上面公布着影评和相关电影描述。
作为该电影院的信息部主管,您需要编写一个 SQL查询,找出所有影片描述为非 boring
(不无聊) 的并且 id 为奇数 的影片,结果请按等级 rating
排列。
例如,下表 cinema
:
+---------+-----------+--------------+-----------+ | id | movie | description | rating | +---------+-----------+--------------+-----------+ | 1 | War | great 3D | 8.9 | | 2 | Science | fiction | 8.5 | | 3 | irish | boring | 6.2 | | 4 | Ice song | Fantacy | 8.6 | | 5 | House card| Interesting| 9.1 | +---------+-----------+--------------+-----------+
对于上面的例子,则正确的输出是为:
+---------+-----------+--------------+-----------+ | id | movie | description | rating | +---------+-----------+--------------+-----------+ | 5 | House card| Interesting| 9.1 | | 1 | War | great 3D | 8.9 | +---------+-----------+--------------+-----------+
答案:
select id,movie,description,rating from cinema where description <> "boring" and MOD(id,2) ORDER BY rating desc
解析:
MOD(n,m)函数 取模运算,返回n被m除的余数(同%操作符)
mod(n,m)
取模运算,返回n被m除的余数(同%操作符)
mysql> select mod(234, 10);
-> 4
mysql> select 234 % 10;
-> 4
mysql> select mod(29,9);
-> 2
来源:oschina
链接:https://my.oschina.net/u/3568600/blog/1812539