class Job < ActiveRecord::Base validates :starts_on, :ends_on, :name, presence: true belongs_to :project scope :project, ->(project) { where(project_id: project.id) } def total_time_logged TimeEntry.where(job_id: id) .sum(:hours) end def total_time_logged_for(activity) TimeEntry.where(job_id: id, activity_id: activity.id) .sum(:hours) end end