Ruby on Rails - Hash of Arrays, group by and sum by column name

Question

I have the following array of hashes:

[{\"idx\"=>\"1234\", \"account\"=>\"abde\", \"money\"=>\"4.00\", \"order\"=>\"00001\"}, {\"idx\"=>\"1235\", \"

Answer 1

you can make your own method for that, something like:

def group_hashes arr, group_field, sum_field
  arr.inject({}) do |res, h|
    (res[h[group_field]] ||= {}).merge!(h) do |key, oldval, newval|
      key.eql?(sum_field) ? (oldval.to_f + newval.to_f).to_s : oldval
    end
    res
  end.values
end

a call group_hashes arr, "order", "money" on you array of hashes example returns:

[{"idx"=>"1234", "account"=>"abde", "money"=>"6.0", "order"=>"00001"}, {"idx"=>"1235", "account"=>"abde", "money"=>"3.00", "order"=>"00002"}]