ruby on rails - Combining group_by and sum -

ruby on rails - Combining group_by and sum -

i have model next attributes:

user_id,  week_id,  project_id,  hours 1         61         1             20 1         62         1              5 1         61         2             15 1         63         1              0 2 61 1 0

my view this:

<tr> 61 | 62 | 63 (week_id) 35 | 5  | 0 (sum of hours per week_id) </tr> all_hours = model.group_by(&:user_id) @all_hours.each |user, hours| %> <tr> hours.each | hr | hour.my_hours

and gives me 2 lines of user 1

how grouping sec time & sum hours per week_id wanted result?

to create more clear (hopefully) :

@hours= model.all.group_by(&:user_id) <% @hours.each |user, hours| %> <tr> <% hours.each |h|%> <td><%= h.hours%></td> <% end %> </tr>

gives me 1 long row per user like: 0.0 20.0 0.0 .... 0.0 15.0 0.0 want sum 20 , 15 within line 0.0 35.0 0.0

i give seek rails 3:

model.select(:week_id). select(model.arel_table[:hours].sum.as("sum_of_hours")).select(:user_id) group(:week_id).group(:user_id)

the library used here arel , part of rails 3, activerecord.

i assume works. haven't tried myself. hope helps.

ruby-on-rails ruby-on-rails-3 group-by sum