recent wiki anniversaries

SQL

select max(rev_timestamp) as last_edit, rev_actor, user_name, user_registration,
case 
when user_registration BETWEEN DATE_SUB(NOW(), INTERVAL (365*5+60) DAY) AND DATE_SUB(NOW(), INTERVAL (365*5) DAY) then '5 years'
when user_registration BETWEEN DATE_SUB(NOW(), INTERVAL (365*10+60) DAY) AND DATE_SUB(NOW(), INTERVAL (365*10) DAY) then '10 years'
when user_registration BETWEEN DATE_SUB(NOW(), INTERVAL (365*15+60) DAY) AND DATE_SUB(NOW(), INTERVAL (365*15) DAY) then '15 years'
when user_registration BETWEEN DATE_SUB(NOW(), INTERVAL (365*20+60) DAY) AND DATE_SUB(NOW(), INTERVAL (365*20) DAY) then '20 years'
when user_registration is null then 'unknown' 
else 'no anniversary'
END as anniversary
from revision 
left join user on rev_actor = user_id
where rev_timestamp > DATE_SUB(NOW(), INTERVAL 365 DAY)
group by rev_actor
order by anniversary
limit 100
SQL

Checking query status...
