SELECT * FROM

(

SELECT logtemp.log_user_text AS `reviewer`,

COUNT(logtemp.log_page) AS `reviews`

FROM (

SELECT log_user_text, log_page

FROM logging

JOIN user_groups ON ug_user = log_user

WHERE log_timestamp BETWEEN 20180100000000 AND NOW()

AND log_type = 'pagetriage-curation'

AND log_action = 'reviewed'

AND ug_group = 'patroller'

AND log_namespace = 0

UNION

SELECT log_user_text, log_page

FROM logging

JOIN user_groups ON ug_user = log_user

WHERE log_timestamp BETWEEN 20180100000000 AND NOW()

AND log_type = 'patrol'

AND log_action = 'patrol'

AND ug_group = 'patroller'

AND log_namespace = 0

UNION

SELECT user_name AS log_user_text, NULL AS log_page

FROM `user`

JOIN user_groups ON ug_user = user_id

WHERE ug_group = 'patroller'

) logtemp

GROUP BY reviewer

) t1

JOIN

(

SELECT logtemp2.log_user_text AS `reviewer`,

MAX(logtemp2.log_timestamp) AS `last review`

FROM (

SELECT log_user_text, log_page

FROM logging

JOIN user_groups ON ug_user = log_user

WHERE log_timestamp BETWEEN 20180100000000 AND NOW()

AND log_type = 'pagetriage-curation'

AND log_action = 'reviewed'

AND ug_group = 'patroller'

AND log_namespace = 0

UNION

SELECT log_user_text, log_page

FROM logging

JOIN user_groups ON ug_user = log_user

WHERE log_timestamp BETWEEN 20180100000000 AND NOW()

AND log_type = 'patrol'

AND log_action = 'patrol'

AND ug_group = 'patroller'

AND log_namespace = 0

) logtemp2

GROUP BY reviewer

) t2

ON t1.reviewer = t2.reviewer

ORDER BY reviews DESC;

​