链接丢失范围的 Rails 活动记录

Question

模型Food 具有范围expired：

Food.rb

class Food < ApplicationRecord
  default_scope { where.not(status: 'DELETED') }
  scope :expired, -> { where('exp_date <= ?', DateTime.now) }
  belongs_to :user
end

在我的控制器中，我链接了按用户和状态过滤食物的条件：

query_type.rb

def my_listing_connection(filter)
  user = context[:current_user]
  scope = Food.where(user_id: user.id)
  if filter[:status] == 'ARCHIVED'
    # Line 149
    scope = scope.where(
      Food.expired.or(Food.where(status: 'COMPLETED'))
    )
  else
    scope = scope.where(status: filter[:status])
  end
  scope.order(created_at: :desc, id: :desc)
  # LINE 157
  scope
end

这是rails日志：

Food Load (2.7ms)  SELECT `foods`.* FROM `foods` WHERE `foods`.`status` !=
'DELETED' 
AND ((exp_date <= '2020-07-02 09:58:16.435609') OR `foods`.`status` = 'COMPLETED')

↳ app/graphql/types/query_type.rb:149

Food Load (1.6ms)  SELECT `foods`.* FROM `foods` WHERE `foods`.`status` != 'DELETED' 
AND `foods`.`user_id` = 1 ORDER BY `foods`.`created_at` DESC, `foods`.`id` DESC
↳ app/graphql/types/query_type.rb:157

为什么活动记录查询在第 157 行丢失了expired 范围（和条件）？

Answer 1

它被忽略是因为where 不期望这样的作用域。但是您可以改用merge。替换

scope = scope.where(
  Food.expired.or(Food.where(status: 'COMPLETED'))
)

与

scope = scope.merge(Food.expired)
             .or(Food.where(status: 'COMPLETED'))

或

scope = scope.where(status: 'COMPLETED').or(Food.expired)