如何避免具有联结 table 的重复行。（如何使用它）？

Question

由于一首歌可以有多个词曲作者，一个词曲作者可以写几首歌曲，所以我创建了一个结点-table songwriter_track。但是我不确定如何用我的普通 track table "combine it"。我希望能够从我的 track table 中获取 select 属性，同时获取歌曲的词曲作者。但不幸的是，我目前的解决方案 returns 歌曲重复。我做错了什么？有办法解决这个问题吗？我必须运行两次查询吗？

这是我的 tables:

   TABLE track(
         track_id     INT PRIMARY KEY
         track_title       VARCHAR(100)
         track_duration    VARCHAR(100)
         lyric_url         VARCHAR(150))

  TABLE songwriter(
        songwriter_id INT  PRIMARY KEY
        songwriter_name VARCHAR(30)  
        UNIQUE INDEX (songwriter_name))

  TABLE songwriter_track(
        id_songwriter INT REFERENCES songwriter(songwriter_id)
        id_track      INT REFERENCES track(track_id)
        PRIMARY KEY (id_songwriter, id_track))


 VIEW `tracks_view` AS "
      "SELECT t.*, s.songwriter_name  "
           "FROM track t "
           "INNER JOIN songwriter_track st "
           "ON t.track_id = st.id_track "
           "INNER JOIN songwriter s "
           "ON s.songwriter_id = st.id_songwriter;";

Answer 1

如果您只想为每个曲目生成一条记录，一种解决方案是将所有词曲作者作为逗号分隔列表放在一列中。

考虑：

select 
    t.track_id, 
    t.track_title, 
    t.track_duration, 
    t.lyric_url,
    group_concat(s.songwriter_name order by s.songwriter_name) songwriters
from track t
inner join songwriter_track st on st.id_track = t.track_id
inner join songwriter s on s.songwriter_id = sr.id_songwriter
group by 
    t.track_id, 
    t.track_title, 
    t.track_duration, 
    t.lyric_url

如何避免具有联结 table 的重复行。（如何使用它）？

How to avoid duplicate rows with junction table. (How to use it)?

mysql

sql

rdbms

如何避免具有联结 table 的重复行。 （如何使用它）？

How to avoid duplicate rows with junction table. (How to use it)?

mysql

sql

rdbms

如何避免具有联结 table 的重复行。（如何使用它）？