gem 'rails', '4.2.7.1'
class Property < Accommodation
has_many :attachments, as: :attached_item, dependent: :destroy
end
class Accommodation < ActiveRecord::Base;
end
class Attachment < ActiveRecord::Base
belongs_to :attached_item, polymorphic: true
end
该关联在 Rails 4.2 中工作得很好
Property.last.attachments
Property Load (0.9ms) SELECT "accommodations".* FROM "accommodations" WHERE "accommodations"."type" IN ('Property') ORDER BY "accommodations"."id" DESC LIMIT 1
Attachment Load (0.5ms) SELECT "attachments".* FROM "attachments" WHERE "attachments"."attached_item_id" = $1 AND "attachments"."attached_item_type" = $2 [["attached_item_id", 1], ["attached_item_type", "Property"]]
Rails 5.0 中的类似关联
class CustomInquiry < ApplicationRecord;
end
class ChildInquiry < CustomInquiry
has_many :text_histories, as: :mailed_item, dependent: :delete_all
end
class TextHistory < ApplicationRecord
belongs_to :mailed_item, polymorphic: true
end
2.4.0 :002 > ChildInquiry.last.text_histories
ChildInquiry Load (1.2ms) SELECT "custom_inquiries".* FROM "custom_inquiries" WHERE "custom_inquiries"."type" IN ('ChildInquiry') ORDER BY "custom_inquiries"."id" DESC LIMIT $1 [["LIMIT", 1]]
TextHistory Load (0.4ms) SELECT "text_histories".* FROM "text_histories" WHERE "text_histories"."mailed_item_id" = $1 AND "text_histories"."mailed_item_type" = $2 [["mailed_item_id", 197], ["mailed_item_type", "CustomInquiry"]]
但是这里第二个查询应该像这样运行:
TextHistory Load (0.4ms) SELECT "text_histories".* FROM "text_histories" WHERE "text_histories"."mailed_item_id" = $1 AND "text_histories"."mailed_item_type" = $2 [["mailed_item_id", 197], ["mailed_item_type", "ChildInquiry"]]
任何人都可以帮助我了解 Rails 5 中的更新内容以及覆盖它的猴子补丁吗?
最佳答案
最新版本的 ActiveRecord 在关联中使用基类,因此当我们使用 STI 时,它会采用基类而不是当前类。
因此,为了解决这个问题,您可以使用 Gem gem "store_base_sti_class"
。
它将使用ActiveRecord关联中的当前类。
这是github链接
关于ruby-on-rails-5 - 使用 STI 时,Rails 5.0 不获取多态关联,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52380283/