Hello, I'm starting out with Ruby On Rails, and I'm making an application that manages expenses. Well what I need to do add up all the expenses of the "value" column and show in the view.
I'm trying the following in ActiveRecord
def total
divida.sum("valor * ")
end
Would that be the right way? How do I show it in the view?
Thank you for your attention!
You can do as the one quoted in the other answer, but never call a method of a model in a view, since model does not communicate with view, and this is one of the fundamentals of MVC. You can call this method in your control, refer to a variable and use it in your view
in your model:
class Payment
def self.total
self.sum(:value)
end
end
in your controller:
class PaymentsController < ApplicationController
def index
@sum_of_payments = Payment.total
end
end
in your view in app / payments / index.html.erb:
<%= @sum_of_payments %>
ps: avoid writing code in Portuguese, and worse, mixing English with Portuguese.
The class representing your model can contain a class method that calculates the sum of all debt values. I'm assuming there is a dividas table in your database, which contains a valor column.
class Divida < ActiveRecord::Base
def self.total
self.sum(:valor)
end
end
Then in your view (for example, the file app/views/divida/index.html.erb ), you can call Divida.total which will return the total of all debts.