Rails 5.1, sum by currency with nested resources - ruby-on-rails

Question

I have a problem with a SUM calculation. I have multiple currency in a table, I have users, I have groups and I have a bets table. The user can join a group via member (user_id and group_id). And the user can share his bet via groupbet (bet_id and member_id). I don't enter in detail here because all this works properly.
I would like to do some SUM calculation in the group view (show). This is where I'd like to display the total amount of money the members of the group spend for there bet. I also would like to use chartkick in the mix to show some nice graph.
This is what I have so far
My controller :
m = Member.where(group_id: #group.id)
gs = Groupbet.where(member_id: m)
#tasks = gs.joins(:bet).select("bets.*, sum(amount) as total")
#amount = gs.joins(:bet).
select(:symb, 'bets.*, sum(amount) AS amount').
where(bet_id: { id: #current_user.bets.all.map(&:id) }).
group(:symb)
#tasks works but SUM all the spendings from the group, that's cool, but I have several currencies so the amount is not correct. This is why I came up with #amount which in the view :
<% #amount.each do |amount| %>
<%= '%.02f' % "#{amount.amount}" %>
<%= "#{amount.symb}" %>
<% end %>
display nothing at all.
the :symb is one of my Currency column btw. In currency I have name and symb, where symbole is this : € or $ for example. In my spending table I have a column amount and the currency_id.
My relations :
class Currency < ApplicationRecord
has_many :bets, dependent: :destroy
has_many :users, through: :bets
end
class Group < ApplicationRecord
has_secure_token :auth_token
has_many :members, :dependent => :destroy
has_many :users, through: :members, source: :user
belongs_to :owner, class_name: "User"
has_many :links, through: :grouplinks
has_many :grouplinks, through: :members
has_many :bets, through: :groupbets
has_many :groupbets, through: :members
has_many :notifications, dependent: :destroy
def to_param
auth_token
end
end
class Groupbet < ApplicationRecord
belongs_to :bet
belongs_to :member
end
class Member < ApplicationRecord
belongs_to :user
belongs_to :group
has_many :grouplinks, dependent: :destroy
has_many :groupbets, dependent: :destroy
validates :user_id, :presence => true
validates :group_id, :presence => true
validates :user_id, :uniqueness => {:scope => [:user_id, :group_id]}
end
class Bet < ApplicationRecord
belongs_to :user
belongs_to :currency
has_many :groupbets, dependent: :destroy
end
class User < ApplicationRecord
has_secure_password
has_many :bets, dependent: :destroy
has_many :currencies, through: :bets
has_many :links, dependent: :destroy
has_many :notifications, dependent: :destroy
has_many :members, :dependent => :destroy
has_many :groups, :through => :members
has_one :owned_group, foreign_key: "owner_id", class_name: "Group"
end
Links has nothing to do here but yeah...
I'm also using groupdate and for chartkick I don't really know because when a user creates a bet he can actually go on his profile and check all the bets he did, as well in a chart. To display this chart, which is working, I'm doing like so :
My helper
def expenses_bet_amount_per_month
#current_user.bets.all.joins(:currency).group('currencies.symb').group_by_month(:date, format: "%B %Y").sum(:amount)
end
date is the date when the user create the bet. Don't ask why I didn't use created_at, doesn't matter :)
And my view :
<%= column_chart expenses_bet_amount_per_month %>
That works. For one single user. But for the group I don't know how I could make that happen.
If anyone can save the situation ? Thank you very much
EDIT :
The code for the single user :
def sums_by_currency_total
Currency.joins(:bets).
select(:symb, 'SUM(bets.amount) AS amount').
where(bets: { id: user_bets_total.map(&:id) }).
group(:symb)
end
def user_spendings_total
user.bets.all
end
That works for one user. Display the SUM from all bets per currency. But for a group ? I don't know

Answer 1

Ok people I managed !!!!
I share the code in case anybody is interested :
def sums_by_currency_group
m = Member.where(group_id: #group.id)
gs = Groupbet.where(member_id: m)
Currency.joins(:bets)
.select(:symb, 'SUM(bets.amount) AS amount')
.where(bets: { id: gs.all.map(&:bet_id) })
.group(:symb)
end
In the view :
<% sums_by_currency_group.each do |sum| %>
<%= '%.02f' % "#{sum.amount}" %> <%= "#{sum.symb}" %>
<% end %>
And there we go. All the SUM from the bets that are shared in each group.
I also solved the problem for chart kick :
def bets_amount_per_month_group
m = Member.where(group_id: #group.id)
gs = Groupbet.where(member_id: m)
Currency.joins(:bets)
.where(bets: { id: gs.all.map(&:bet_id) })
.group('currencies.symb')
.group_by_month(:date, format: "%B %Y")
.sum(:amount)
end
In the view :
<%= column_chart bets_amount_per_month_group %>
Et voila ! Nice chart of all the bets shared in the group. I used the same method as the calculation and it worked !! Olé !!