Question

Hi I have seemingly simple problem which is causing my head to hurt.

I have three tables in a mysql db which describe a many-to-many relationship between article title and several (variable number) keywords.

Article:

+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| volume_id  | varchar(11)  | NO   | MUL | NULL    |                |
| title      | longtext     | NO   |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+

Keywords:

+---------+--------------+------+-----+---------+----------------+
| Field   | Type         | Null | Key | Default | Extra          |
+---------+--------------+------+-----+---------+----------------+
| id      | int(11)      | NO   | PRI | NULL    | auto_increment |
| keyword | varchar(355) | NO   |     | NULL    |                |
+---------+--------------+------+-----+---------+----------------+

Article_keywords (through table):

+------------+---------+------+-----+---------+----------------+
| Field      | Type    | Null | Key | Default | Extra          |
+------------+---------+------+-----+---------+----------------+
| id         | int(11) | NO   | PRI | NULL    | auto_increment |
| article_id | int(11) | NO   | MUL | NULL    |                |
| keyword_id | int(11) | NO   | MUL | NULL    |                |
+------------+---------+------+-----+---------+----------------+

What I want is a single table where one row includes the title and its associated keywords, so that it can be edited by someone who is not a programmer. Of course I will also need to do the reverse to update the fields, but I think that is much more straightforward.

Is this even possible in MySQL or will have to use a scripting language to accomplish this?

Any help much appreciated.

Answer 1

SELECT a.ID, a.title, c.keyword
FROM    `Article` a INNER JOIN `Article_keywords` b
            ON a.id = b.article_id
        INNER JOIN `Keywords` c 
            ON b.keyword_ID = c.id

OR if you want to have a single row for every title

SELECT a.ID, a.title, GROUP_CONCAT(c.keyword) `keyword`
FROM    `Article` a INNER JOIN `Article_keywords` b
            ON a.id = b.article_id
        INNER JOIN `Keywords` c 
            ON b.keyword_ID = c.id
GROUP BY a.ID