620. 有趣的电影

﹏ヽ暗。殇╰゛Y 2022-03-12 06:54 179阅读 0赞

# 题目来源 #

[leetcode][]

# 题目描述 #

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     |
    +---------+-----------+--------------+-----------+

非OJ

> SELECT * FROM  cinema WHERE id %2 = 1  AND description <> 'boring' ORDER BY rating;
    > SELECT * FROM  cinema WHERE description <> 'boring' AND id % 2 = 1  ORDER BY rating;
    > select * from cinema WHERE MOD(id, 2)=1 AND description <> 'boring' ORDER BY rating;

![在这里插入图片描述][2019030514382414.png]

> 对索引列进行运算导致索引失效,我所指的对索引列进行运算包括(+，-，\*，/，! 等)  
> ORDER BY 虽然默认desc，但是还是写上好

# 题目解答 #

> select * from cinema WHERE MOD(id, 2)=1 AND description <> 'boring' ORDER BY rating DESC;
    > SELECT * FROM  cinema WHERE  id % 2 = 1 AND description <> 'boring'  ORDER BY rating DESC;

[leetcode]: https://leetcode-cn.com/problems/not-boring-movies/
[2019030514382414.png]: /images/20220312/f58909687ae748a7b39b176ccefdf993.png