Links to absent portals

This query lists template uses such as {{Portal|Foo}} or {{Portal|History|Foo|Science}} where Foo is not a portal nor a redirect to one.  If multiple portals are listed for one article, they usually appear in the same template call.  There will be some false positives, where an article has no such template but links to a portal in another way.  However, no actual portals are listed.  Most should be removed but some can usefully be replaced by similar portals which do exist.  For example, {{Portal|Judaïsme}} obviously attempts to link the actual [[Portal:Judaism]].

SQL

SELECT pl_title, COUNT(DISTINCT Pa.page_title), MIN(CONCAT(
 CASE Pa.page_namespace WHEN 0 THEN " " WHEN 10 THEN "Template:" WHEN 14 THEN "Category:" END
 , Pa.page_title)) AS page1, MAX(CONCAT(
 CASE Pa.page_namespace WHEN 0 THEN " " WHEN 10 THEN "Template:" WHEN 14 THEN "Category:" END
 , Pa.page_title)) AS page2
FROM pagelinks
JOIN page Pa ON Pa.page_id=pl_from AND Pa.page_namespace IN (10) AND Pa.page_title NOT LIKE "Portal/%"
JOIN templatelinks ON tl_from=pl_from AND tl_title LIKE "Portal%"
WHERE pl_namespace=100 AND pl_title NOT LIKE "%/%"
AND NOT EXISTS (SELECT 1 FROM page WHERE page_title=pl_title AND page_namespace=100)
GROUP BY pl_title
ORDER BY pl_title

SQL

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