~ - Quarry

SQL

#USE stop;
USE commonswiki_p;
SET @tltitle = 'Category_redirect';
SET @cltitle = 'Category_redirects';
SELECT REPLACE(CONCAT('# [[:Category:', p1.page_title, ']] → [[:Category:', pl1.pl_title, ']] → [[:Category:', pl2.pl_title, ']]'), '_', ' ')
FROM page p1
INNER JOIN categorylinks cl1 ON cl1.cl_from = p1.page_id AND cl1.cl_to = @cltitle
INNER JOIN templatelinks tl1 ON tl1.tl_from = p1.page_id AND tl1.tl_from_namespace = 14 AND tl1.tl_namespace = 10 AND tl1.tl_title = @tltitle
INNER JOIN pagelinks pl1 ON pl1.pl_from = p1.page_id AND pl1.pl_from_namespace = 14 AND pl1.pl_namespace = 14
INNER JOIN page p2 ON p2.page_title = pl1.pl_title
INNER JOIN categorylinks cl2 ON cl2.cl_from = p2.page_id AND cl2.cl_to = @cltitle
INNER JOIN templatelinks tl2 ON tl2.tl_from = p2.page_id AND tl2.tl_from_namespace = 14 AND tl2.tl_namespace = 10 AND tl2.tl_title = @tltitle
INNER JOIN pagelinks pl2 ON pl2.pl_from = p2.page_id AND pl2.pl_from_namespace = 14 AND pl2.pl_namespace = 14
WHERE p1.page_namespace = 14
AND p2.page_namespace = 14
GROUP BY p1.page_title #HAVING COUNT(p1.page_id) = 1
LIMIT 20;
SQL

Checking query status...
