I have the following models:
class Client < ActiveRecord::Base has_many :accounts, dependent: :destroy end
class Account < ActiveRecord::Base belongs_to :client has_many :operations, dependent: :destroy end
class Operation < ActiveRecord::Base belongs_to :account end
I manage to extract clients and all their operations grouped by client as follows:
scope :operations_by_client, joins(:client, :operations).select(‘clients.firstname, clients.lastname, sum(operations.total) as total’).group(‘clients.id, clients.firstname, clients.lastname’).order(‘clients.lastname’)
Now how to tune/change it in case if I don’t need to calculate SUM of the operations but to use a special method that would calculate the sum of all the operations for the specified client? I mean that I should exclude certain total values from the calculation depending on the operation type.
Thanks and regards