Abkürzungs-Lemma

SQL

WITH BklAbkz AS (
     SELECT page_id AS bkl_page, UPPER(CONVERT(REPLACE(page_title, '_Begriffsklärung', '') USING utf8)) AS bkl_title
       FROM page, page_props
      WHERE page_namespace = 0
        AND page_id = pp_page
        AND pp_propname = 'disambiguation' /* <-- das ist eine Begriffsklärungsseite */
  UNION
     SELECT page_id AS bkl_page, UPPER(CONVERT(page_title USING utf8)) AS bkl_title
       FROM page, categorylinks
      WHERE page_namespace = 0
        AND page_id = cl_from
        AND cl_to = 'Abkürzung'
  )
SELECT page_title
  FROM page LEFT JOIN BklAbkz
              ON bkl_title = page_title
             AND page_id != bkl_page
 WHERE page_namespace = 0
   AND page_title = UPPER(CONVERT(page_title USING utf8)) /* keine Kleinbuchstaben */
   AND page_title RLIKE "[A-Z]" /* Enthält einen Buchstaben */
   AND page_title RLIKE "[^A-Z1-9]" /* Enthält ein Zeichen das kein Buchstabe7Ziffer ist */
   AND page_title NOT RLIKE "[-–_]" /* Kein Leerzeichen (_), kein Bindestrich */
   AND bkl_page IS NULL
SQL

Checking query status...
