Inactive user rights

SQL

use fawiki_p;
SELECT DISTINCT
  user_name,
  rev_timestamp,
  GROUP_CONCAT(ug_group)
FROM user
JOIN user_groups
ON ug_user = user_id
JOIN revision
ON rev_user = user_id
WHERE user_name NOT IN (SELECT
                          user_name
                        FROM user
                        JOIN user_groups
                        ON ug_user = user_id
                        WHERE ug_group IN ('sysop','bureaucrat'))
AND (SELECT
       MAX(rev_timestamp)
     FROM revision
     WHERE rev_user = user_id) < DATE_FORMAT(DATE_SUB(NOW(),INTERVAL 6 MONTH),'%Y%m%d%H%i%s')
AND rev_timestamp = (SELECT
                       MAX(rev_timestamp)
                     FROM revision
                     WHERE rev_user = user_id)
GROUP BY user_name;
SQL

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