如何从 mysql 中的 3 个表中检索数据 - 加入帮助？

Question

表格布局：

您好，我想从上述表格中检索信息组合，主要是“episode”表格中的单行结果，以及“tvshow”表格和“season”表格中的一些信息，即也仅适用于我想从“episode”表中检索的那一行，这是我目前的查询：

Select tvshow.series_name, season.season_banner, season.season_poster, episode.season_num, episode.episode_num, episode.episode_name, episode.plot
FROM tvshow,season,episode
WHERE episode.tvshow_id = 1 AND episode.season_num = 1 and episode.episode_num = 1

我知道我需要使用联接，但我不确定如何执行此操作，以合并 3 个表的结果。

我最接近返回单行的是：

SELECT tvshow.series_name, season.season_banner, season.season_poster, episode.season_num, episode.episode_num, episode.episode_name, episode.plot
FROM episode
INNER JOIN tvshow ON episode.tvshow_id = tvshow.tvshow_id
INNER JOIN season ON episode.season_num = season.season_num
WHERE episode.tvshow_id =1
AND episode.season_num =1
AND episode.episode_num =1

返回我想要的行，但除了仅存在于季节表（季节横幅和海报）中的字段为空白之外，还返回相同的第二行。

Answer 1

   First you need to normalize your data base.
   Your table structure like thata  
        tvshow -->   tv_id as  primary key
        season -->   tv_id as foreign key 
        episode -->  tv_id as foreign key 

   Your join query 

    Select tvshow.series_name, season.season_banner, season.season_poster, episode.season_num, episode.episode_num, episode.episode_name, episode.plot 
    FROM tvshow 
    JOIN season on season.tv_id= tvshow.tv_id
    JOIN episode on episode.tv_id= tvshow.tv_id
    WHERE episode.tv_id = 1 

Answer 2

使用左连接

select ts.series_name,ss.season_banner,es.season_num from tvshow as ts inner join season as ss on ss.tvshow_id=ts.tvshow_id inner join episod as es on ss.season_num=es.season_num where ts.tvshow_id=1 and ss.season_num=2 and es.episode_num=1;