mysql - 对于给定的一组数据，如何检查输入是否具有整组数据？

Question

翻译举例:
对于给定的一组电影，我如何获取其类别并判断我们是否获得了完整的电影集作为输入？

        -------------------------
        | CATEGORY   | MOVIE    |
        -------------------------
        | Fantasy    | Hobbit   |
        | Fantasy    | Hellboy  |
        | Romance    | Twilight |
        | Mystery    | Memento  |
        | Mystery    | Get Out  |

例如，如果我传入 Hobbit, Hellboy 作为输入，我应该返回

        -------------------------------------------
        | CATEGORY | MOVIES          | HASFULLSET |
        -------------------------------------------
        | Fantasy  | Hobbit, Hellboy | 1          |

如果我传入 Hobbit, Twilight 作为输入，我应该返回

        -------------------------------------
        | CATEGORY | MOVIES    | HASFULLSET |
        -------------------------------------
        | Fantasy  | Hobbit    | 0          |
        | Romance  | Twilight  | 1          |

如果不使用子查询，我就无法超越这个。

SELECT Category, COUNT(*) AS GRP_COUNT 
FROM movie
WHERE Movies IN (@movies)
GROUP BY Category

Answer 1

尝试以下查询:

SET @movies = 'Hobbit,Hellboy';
select category,
       group_concat(case when find_in_set(Movie,@movies) then movie end) AS movies,
           case when
             count(*) = sum(case when find_in_set(Movie,@movies) then 1 else 0 end)
           then 1 else 0 end FullSet
from tbl
group by category
having movies != '';

Demo