Rails add divide calculation to existing query - sql

Question

I have a query in which I pull all users who have invested in the portfolio, like below:
class PortfolioShareholdersQuery
def initialize(portfolio)
#portfolio = portfolio
end
def call
User.joins(:cash_transactions)
.where(cash_transactions: { to_wallet: portfolio.wallet })
.select('users.*, SUM(cash_transactions.shares_number) as total_shares_number')
.group('users.id')
end
attr_reader :portfolio
end
Is it possible to add inside of above query a line that will do the division of two numbers as below?
(user.total_shares_number / portfolio.portfolio_setup_infos.last.total_shares_sold)
# total_shares_number comes from first select
# portfolio_setup_infos is a has_many relation to portfolio
[Edit]
#models association
class User < ApplicationRecord
has_one :wallet, as: :walletable
has_many :cash_transactions, through: :wallet
end
class Portfolio < ApplicationRecord
has_one :wallet, as: :walletable
end
class Wallet < ApplicationRecord
belongs_to :walletable, polymorphic: true
has_many :cash_transactions
end
class CashTransaction < ApplicationRecord
belongs_to :wallet
belongs_to :to_wallet, class_name: 'Wallet', optional: true
end
[Edit 2]
> divisor = portfolio.portfolio_setup_infos.last.total_shares_sold
PortfolioSetupInfo Load (0.5ms) SELECT "portfolio_setup_infos".* FROM "portfolio_setup_infos" WHERE "portfolio_setup_infos"."portfolio_id" = $1 ORDER BY "portfolio_setup_infos"."id" DESC LIMIT $2 [["portfolio_id", 6], ["LIMIT", 1]]
=> 263
> shareholders = User.joins(:cash_transactions).where(cash_transactions: { to_wallet: portfolio.wallet }).select("users.*, SUM(cash_transactions.shares_number) as total_shares_number, (total_shares_number/#{divisor}").group('users.id')
Wallet Load (0.6ms) SELECT "wallets".* FROM "wallets" INNER JOIN "spv_setups" ON "wallets"."walletable_id" = "spv_setups"."id" WHERE "spv_setups"."portfolio_id" = $1 AND "wallets"."walletable_type" = $2 LIMIT $3 [["portfolio_id", 6], ["walletable_type", "SpvSetup"], ["LIMIT", 1]]
User Load (3.3ms) SELECT users.*, SUM(cash_transactions.shares_number) as total_shares_number, (total_shares_number/263 FROM "users" INNER JOIN "wallets" ON "wallets"."walletable_type" = $1 AND "wallets"."walletable_id" = "users"."id" INNER JOIN "cash_transactions" ON "cash_transactions"."wallet_id" = "wallets"."id" WHERE "cash_transactions"."to_wallet_id" = $2 GROUP BY "users"."id" /* loading for inspect */ LIMIT $3 [["walletable_type", "User"], ["to_wallet_id", 8], ["LIMIT", 11]]
Traceback (most recent call last):
ActiveRecord::StatementInvalid (PG::SyntaxError: ERROR: syntax error at or near "FROM")
LINE 1: ... as total_shares_number, (total_shares_number/263 FROM "user...
^

Answer 1

class Portfolio < ApplicationRecord
def divisor
portfolio_setup_infos.last.total_shares_sold
end
end
class PortfolioShareholdersQuery
def initialize(portfolio)
#portfolio = portfolio
#divisor = portfolio.divisor.to_f
end
def call
select =<<-SEL.squish
users.*,
SUM(cash_transactions.shares_number) as total_shares_number,
(SUM(cash_transactions.shares_number)/#{divisor}) as ratio
SEL
User.joins(:cash_transactions)
.where(cash_transactions: { to_wallet: portfolio.wallet })
.select(select)
.group('users.id')
end
attr_reader :portfolio, :divisor
end