USE fiwiki_p;

SELECT

    rev_user_text,

    COUNT(1) AS num_contribs

FROM revision_userindex

INNER JOIN page ON rev_page = page_id

WHERE

    page_namespace IN (4) AND 

    rev_timestamp BETWEEN

        DATE_FORMAT(DATE_SUB(NOW(), INTERVAL 30 DAY), "%Y%m%d%H%i%S") AND

        DATE_FORMAT(NOW(), "%Y%m%d%H%i%S")

AND NOT EXISTS (SELECT * FROM user_groups WHERE ug_user = rev_user AND ug_group = 'bot')

GROUP BY rev_user_text

ORDER BY num_contribs DESC

LIMIT 50