Question

我有两张桌子：

1.advertiser_accounts

create table if not exists advertiser_accounts (
   advertiser_id int(11) not null,
   deal_type_id int(11) not null,
   primary key (advertiser_id),
   CONSTRAINT account_advertiser_refs FOREIGN KEY (advertiser_id) REFERENCES advertisers (ap_advertiser_id ),
  CONSTRAINT deal_types_refs FOREIGN KEY (deal_type_id) REFERENCES  deal_types (id)
);

2。广告客户

Advertiser(id: integer, ap_advertiser_id: integer)

在模特：

的 AdvertiserAccount

class AdvertiserAccount < ActiveRecord::Base
 belong_to :advertiser   
end

广告客户

class Advertiser < ActiveRecord::Base
 has_one :advertiser_account
end

我想将advertiser_accounts中的advertiser_id映射到广告客户表中的ap_advertiser_id

在控制台上：AdvertiserAccount.first.advertiser

AdvertiserAccount加载（0.2ms）SELECT advertiser_accounts。* FROM advertiser_accounts ORDER BY advertiser_accounts。advertiser_id ASC LIMIT 1 广告客户加载（0.2ms）SELECT advertisers。* FROM advertisers WHERE advertisers。id = 153371 LIMIT 1

结果我得到了

但是，我想要这样的查询：

AdvertiserAccount加载（0.2ms）SELECT advertiser_accounts。* FROM advertiser_accounts ORDER BY advertiser_accounts。advertiser_id ASC LIMIT 1 广告客户加载（0.2ms）SELECT advertisers。* FROM advertisers WHERE advertisers。ap_advertiser_id = 153371 LIMIT 1

Answer 1

您是否检查ap_advertiser_id是否具有唯一键约束或主键约束（如果不这样做）。

您违反了配置原则的约定，因此您必须在模型中明确指定主键和外键。

尝试将模型更改为 -

class AdvertiserAccount < ActiveRecord::Base
  belong_to :advertiser, :foreign_key => :ap_advertiser_id,  :primary_key => :advertiser_id   
end

class Advertiser < ActiveRecord::Base
   has_one :advertiser_account,  :primary_key => :ap_advertiser_id, :foreign_key => :advertiser_id
end

当ID以外的外键时，协会不工作

1 个答案: