Question

I have the following “problem”.

Table “labels” include the record labels.
Table “albums” include the albums, and a field with the labels of the album in question, formatted like “1,4,9”.

Now I want to get the label names along with the album name, release year, artist etc. I have everything but the label names figured out! It seems like FIND_IN_SET won’t work with commas… Can you guys please help me, or do I have to use a secondary query for the label names?

Thank you!

Answer 1

The problem is that your schema is wrong. You do not store the relationship between albums and labels as a comma-separated list. Any column’s value should always be atomic (single valued).

The way to store a many-to-many relationship like this is with a new table.

CREATE TABLE artist_label (artist_id int, label_id int, primary key (artist_id, label_id));
INSERT INTO artist_label (1, 1);
INSERT INTO artist_label (1, 4);
INSERT INTO artist_label (1, 9);

Now retrieving the artist and their label info at the same time is easy.

SELECT
  artist.*,
  label.*
FROM
  artist
INNER JOIN
  artist_label
ON
  artist_label.artist_id = artist.id
INNER JOIN
  label
ON
  label.id = artist_label.label_id