Articles cathgorized under a parent and child categories

SQL

USE fawiki_p;
# child and parent category in an article
SELECT page_title title, chld.cl_to child_category, prnt.cl_to parent_category
FROM categorylinks AS chld JOIN page ON chld.cl_from = page_id AND page_namespace = 0 AND page_is_redirect = 0
JOIN categorylinks AS prnt ON prnt.cl_from = page_id

# none is hidden
WHERE NOT EXISTS (
  SELECT NULL
  FROM page JOIN page_props ON page_id = pp_page
  WHERE page_namespace = 14
  AND page_is_redirect = 0
  AND (
    page_title = chld.cl_to
    OR page_title = prnt.cl_to
  )
  AND pp_propname = 'hiddencat'
)

# prnt is parent of chld
AND prnt.cl_to IN (
  SELECT cl_to
  FROM categorylinks JOIN page ON cl_from = page_id
  WHERE page_title = chld.cl_to
  AND page_namespace = 14
  AND page_is_redirect = 0
)

AND prnt.cl_to <> 'صفحه‌های_ابهام‌زدایی'

ORDER BY prnt.cl_to

LIMIT 400;
SQL

Checking query status...
