Question

我有三张这样的表：

电影：id，名称
标签：id，name，value
标记：id，电影（FK），标签（FK）

因此，每部电影都有自己的一组标签。我需要的是根据标签集检索类似的电影。我想说出按照匹配标签的数量排序的10部电影。

如果我创建如下的视图，它会让MySQL消失。 “tag”和“tagged”表中都有30k +条记录。

create view relatedtags as 

select
    entityLeft.id as id,
    entityRight.id as rightId,
    count(rightTagged.id) as matches

from
    entity as entityLeft join tagged as leftTagged on leftTagged.entity = entityLeft.id, 
    entity as entityRight join tagged as rightTagged on rightTagged.entity = entityRight.id

where leftTagged.tag = rightTagged.tag
and entityLeft.id != entityRight.id
group by entityLeft.id, entityRight.id

Answer 1

这将返回所有电影的列表，这些电影共享至少1个标签，并且通过减少共同标签的数量排序给定的<current_movie_id>

SELECT movie.*, count(DISTINCT similar.tag) as shared_tags FROM movie INNER JOIN 
    ( tagged AS this_movie INNER JOIN tagged AS similar USING (tag) )
    ON similar.movie = movie.id
WHERE this_movie.movie=<current_movie_id>
AND   movie.id != this_movie.movie
GROUP BY movie.id
ORDER BY shared_tags DESC

希望能为您提供一些工作

如何根据标签获取类似的对象

1 个答案: