Cohort by age and Region

select

A.memberid as memberid,
A.age as age,
A.rid,
B.region,
Date(A.MFTDate) as MFTdate,
date(A.lastactivedate) as lastactivedate

from

(select
m.id as memberid,
TIMESTAMPDIFF(YEAR, str_to_date(m.birthday, '%Y%m%d'), r.start_at) AS age,
r.id as rid,
min(r.start_at) as MFTdate,
Max(r.start_at) as lastactivedate

from  members m

left outer join reservations r on m.id = r.member_id
join charges c on m.id = c.member_id

Where r.start_at != 0
and m.imaginary = 'normal'
and c.kind = 'subscriptionFee'


group by m.id) A

left join

(select
r.id as rid,
z.region as region
from reservations r
left outer join zones z on z.id = r.start_zone_id
group by r.id) B

on A.rid = B.rid