Grouping by date, with 0 when count() yields no lines

Question

I\'m using Postgresql 9 and I\'m fighting with counting and grouping when no lines are counted.

Let\'s assume the following schema :

create table vie         


        

Answer 1

This query will give you the output what your are looking for,

select to_char(date_event, 'YYYY-MM-DD HH24:00') as time, count (to_char(date_event, 'HH24:00')) as count from views where date(date_event) > '2012-01-01' and date(date_event) > '2012-01-07' group by time order by time;