get from 2 tables which are connected

[eluser]vitoco[/eluser]
This is the query, but analize it, and read documentation to learn well.

Code:

SELECT
  a.id AS article_id ,
  a.name AS article_name ,
  COUNT( c.id ) AS num_categories ,
  GROUP_CONCAT( c.name ) AS categorie_names
FROM
  article AS a
LEFT JOIN
  article_cats AS ac
ON
  ( a.id = ac.article_id )
LEFT JOIN
  cats AS c
ON
  ( ac.cat_id = c.id )
GROUP BY
  a.id

if you need to add conditions, use WHERE and/or HAVING depending on the field

Saludos