student vs faculty course views in Moodle by date, day of week, and hour

gistfile1.sql

select to_timestamp(ml.time)::date as date,
extract(dow from to_timestamp(ml.time)) as dow,
extract(hour from to_timestamp(ml.time)) as hour,
sum(case when mr.name='Student' then 1 else 0 end) as student_logins,
sum(case when mr.name='Teacher' then 1 else 0 end) as fac_staff_logins
from mdl_log ml
join mdl_context mcon on mcon.contextlevel=50 and mcon.instanceid=ml.course
join mdl_role_assignments mra on mra.contextid=mcon.id
join mdl_role mr on mr.id=mra.roleid
where to_timestamp(ml.time) > '1/14/2013'
and ml.action='view' and ml.module='course'
group by to_timestamp(ml.time)::date,
extract(dow from to_timestamp(ml.time)),
extract(hour from to_timestamp(ml.time))
order by 1,3;