update_all (ActiveRecord::Base)

    # File lib/active_record/base.rb, line 742
          def update_all(updates, conditions = nil, options = {})
            sql  = "UPDATE #{quoted_table_name} SET #{sanitize_sql_for_assignment(updates)} "
            scope = scope(:find)
            add_conditions!(sql, conditions, scope)
            add_order!(sql, options[:order], nil)
            add_limit!(sql, options, nil)
            connection.update(sql, "#{name} Update")
          end