Ruby on rails 在记录之间交换关联
我们有:Ruby on rails 在记录之间交换关联,ruby-on-rails,ruby,ruby-on-rails-4,rails-activerecord,Ruby On Rails,Ruby,Ruby On Rails 4,Rails Activerecord,我们有: class Dice < ActiveRecord::Base belongs_to :sign_a, class_name: 'Sign' belongs_to :sign_b, class_name: 'Sign' belongs_to :sign_c, class_name: 'Sign' ... belongs_to :dice_place, polymorphic: true validates :sign_a, :sign_b, :sign_
class Dice < ActiveRecord::Base
belongs_to :sign_a, class_name: 'Sign'
belongs_to :sign_b, class_name: 'Sign'
belongs_to :sign_c, class_name: 'Sign'
...
belongs_to :dice_place, polymorphic: true
validates :sign_a, :sign_b, :sign_c, ..., :dice_place, presence: true
end
class BagDicePlace < ActiveRecord::Base
has_one :dice, as: :dice_place, dependent: :destroy
end
假设我们不知何故得到了一个记录袋骰位置1和袋骰位置2。在每个记录中,已经加载了所有子关联的关联骰子。理论上,它应该在一个事务中保持两次更新。但我不知道怎么做。如何通过对数据库生成最少数量的调用来交换这些骰子的位置 好吧,如果大家都保持沉默,我将提供他自己的版本
d1 = bag_dice_place_1.dice
d2 = bag_dice_place_2.dice
Dice.transaction do
if d1
d1.update(dice_place: bag_dice_place_2)
end
if d2
d2.update(dice_place: bag_dice_place_1)
end
end
bag_dice_place_1.association(:dice).target = d2
bag_dice_place_2.association(:dice).target = d1