en pages cathgorized under a parent and child categories

SQL

USE enwiki_p;
# first and second category of an article
SELECT page_title, chld.cl_to#, prnt.cl_to
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 mother 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 page_title = '!Hero_(album)'

#LIMIT 5;
SQL

Checking query status...
