it.wiki EGO: Categorie di squadre con più allenatori o giocatori

SQL

use itwiki_p;
SELECT
	p_nation.page_title AS nation,
    p_squads.page_title AS squads,
    p_squad .page_title AS squad,
    GROUP_CONCAT( (
      SELECT *
      FROM
      	categorylinks AS clplayers
      		JOIN page AS p_players ON ( clplayers.cl_from = p_squad.page_id )
      WHERE
      	clplayers.cl_to = p_squad.page_title
    ) ) as stuff
    FROM
	     categorylinks  AS cl1
	JOIN page           AS p_nation ON ( cl1.cl_from = p_nation.page_id    )
    JOIN categorylinks  AS cl2      ON ( cl2.cl_to   = p_nation.page_title )
   	JOIN page           AS p_squads ON ( cl2.cl_from = p_squads.page_id    )
    JOIN categorylinks  AS cl3      ON ( cl3.cl_to   = p_squads.page_title )
    JOIN page           AS p_squad  ON ( cl3.cl_from = p_squad .page_id    )
WHERE
	cl1.cl_to   = 'Squadre_sportive_per_nazione'             AND
    cl2.cl_type = 'subcat'                                   AND
    cl3.cl_type = 'subcat'                                   AND
    p_nation.page_title NOT LIKE '%_di_%'                    AND
    p_squads.page_title NOT LIKE 'Squadre_automobilistiche%' AND

    # assuming that the squad here is really a squad... but it's not
#    (
#      SELECT *
#      FROM
#      	categorylinks AS clplayers
#      		JOIN page AS p_players ON ( clplayers.cl_from = p_squad.page_id )
#      WHERE
#      	clplayers.cl_to = p_squad.page_title
#    )
SQL

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