mysql - 嵌套 GROUP_CONCAT MySQL？

Question

好吧，假设我有一个类似于我提供的示例中的数据库布局。在上面的示例中，电影有多种语言版本，而这些 movie_releases 也有不同影院的影院版本。

现在，如果我想查询数据库以获取电影的所有影院发行以及所有 movie_releases，我该怎么做？

我目前的代码是:

select
      GROUP_CONCAT(movie.name, ",", language.lang, ",", GROUP_CONCAT(theatre.name)) as releases
from
    movie
        left join movie_releases on movie_releases.movie_id = movie.id
        left join language on movie_release.language_id = language.id
        left join theatre_release on theatre_release.movie_release_id = movie_release.id
        left join theatre on theatre.id = theatre_release.theatre_id

显然这不起作用，因为您不能像这样嵌套 GROUP_CONCAT 函数。

我想要的输出是这样的

["Spiderman", "English", ["Cinema Theatre", "Garden Cinemas"]]
["Spiderman", "Spanish", ["El Cine Grande"]]
["Batman", "English", ["Town Movies"]]

Answer 1

SELECT
    CONCAT(
        '["', `movie`.`name`, '"',
        ', ',
        '"', releases.lang, '"',
        ', [',
        releases.theatres,
        ']]'
    ) AS `release`
FROM
    movie
LEFT JOIN (
    SELECT
        movie_id,
        `language`.lang,
        GROUP_CONCAT('"', theatre.`name`, '"') AS theatres
    FROM
        movie_release
    LEFT JOIN theatre_release ON theatre_release.movie_release_id = movie_release.id
    LEFT JOIN theatre ON theatre.id = theatre_release.theatre_id
    LEFT JOIN `language` ON `language`.id = movie_release.language_id
    GROUP BY
        movie_id,
        language_id
) AS releases ON releases.movie_id = movie.id

您可以将影院分组到一个子选择中，然后根据它们与发行版的关系将它们加入到电影中。

通过以您的格式引入数据，可能会使查询更难阅读。所以这里是没有花哨格式的查询。

SELECT
    CONCAT(
        `movie`.`name`,
        ' ',
        releases.lang,
        ' ',
        releases.theatres
    ) AS `release`
FROM
    movie
LEFT JOIN (
    SELECT
        movie_id,
        `language`.lang,
        GROUP_CONCAT(theatre.`name`) AS theatres
    FROM
        movie_release
    LEFT JOIN theatre_release ON theatre_release.movie_release_id = movie_release.id
    LEFT JOIN theatre ON theatre.id = theatre_release.theatre_id
    LEFT JOIN `language` ON `language`.id = movie_release.language_id
    GROUP BY
        movie_id,
        language_id
) AS releases ON releases.movie_id = movie.id

要添加分隔符，您只需调整 CONCAT 或 GROUP_CONCAT