WITH cte_math (page_id, page_title, priority) AS (

  SELECT

    main.page_id,

    main.page_title,

    cl.cl_to #REPLACE(cl.cl_to,'-priority_mathematics_articles','')

  FROM page as talk

  INNER JOIN page AS main ON main.page_title = talk.page_title

  INNER JOIN categorylinks AS cl ON cl.cl_from = talk.page_id 

​

  WHERE

    main.page_title NOT IN (

      SELECT page_title FROM page

      INNER JOIN categorylinks AS cl ON cl.cl_from = page.page_id

      WHERE cl.cl_to IN (

        'FA-Class_biography_articles',

        'FL-Class_biography_articles',

        'FM-Class_biography_articles',

        'GA-Class_biography_articles',

        'B-Class_biography_articles',

        'C-Class_biography_articles',

        'Start-Class_biography_articles'

        'Stub-Class_biography_articles',

        'List-Class_biography_articles',

        'Disambig-Class_biography_articles',

        'Redirect-Class_biography_articles',

        'Unassessed_biography_articles'))

    AND main.page_namespace = 0

    AND main.page_is_redirect = 0

    AND cl.cl_to IN (

      'Top-priority_mathematics_articles',

      'High-priority_mathematics_articles',

      'Mid-priority_mathematics_articles',

      'Low-priority_mathematics_articles',

      'NA-priority_mathematics_articles',

      'Unknown-priority_mathematics_articles')

)

​

SELECT

    #_from.page_title AS from_page,

    _to.page_title AS to_page,

    SUM(CASE WHEN _from.priority = 'Top-priority_mathematics_articles' THEN 1 ELSE 0 END) AS Top,

    SUM(CASE WHEN _from.priority = 'High-priority_mathematics_articles' THEN 1 ELSE 0 END) AS High,

    SUM(CASE WHEN _from.priority = 'Mid-priority_mathematics_articles' THEN 1 ELSE 0 END) AS Mid,

    SUM(CASE WHEN _from.priority = 'Low-priority_mathematics_articles' THEN 1 ELSE 0 END) AS Low,

    SUM(CASE WHEN _from.priority = 'NA-priority_mathematics_articles'

               OR _from.priority = 'Unknown-priority_mathematics_articles' THEN 1 ELSE 0 END) AS NA

​

  FROM cte_math AS _from

  INNER JOIN pagelinks AS pl ON _from.page_id = pl.pl_from

  INNER JOIN linktarget AS lt ON pl.pl_target_id = lt.lt_id

  INNER JOIN cte_math AS _to ON lt.lt_id = _to.page_id

  GROUP BY _to.page_title