SQL flera rader i en

Detta är i grunden en pivotfråga. Jag skulle göra det med villkorlig aggregering:

select user, access_date,
       max(case when FORMFACTOR = 'Mobile' then 1 else 0 end) as KEY_MOBILE,
       max(case when FORMFACTOR = 'Desktop' then 1 else 0 end) as KEY_DESKTOP,
       (case when max(case when FORMFACTOR = 'Mobile' then 1 else 0 end)  > 0 and
                  max(case when FORMFACTOR = 'Desktop' then 1 else 0 end) > 0
             then 1 else 0
        end) as KEY_MOBILE_DESKTOP
from table t
group by user, access_date;