Question

我有两个模型，一个名为BusinessUser，另一个名为BusinessPlace。 BusinessUser可以有许多BusinessPlaces

class BusinessUser < ActiveRecord::Base  
  has_many :BusinessPlaces
end

class BusinessPlace < ActiveRecord::Base
  belongs_to :BusinessUser
end

当我尝试访问@ business_user.BusinessPlaces.count时，获取构建并在DB上运行的sql是

SELECT COUNT(*) FROM "business_places"  WHERE "business_places"."business_user_id" = 1

但在迁移和数据库中，业务用户标识的列是BusinessUser_id，这使查询失败。为什么sql构建错误？我用控制台来创建模型。

Answer 1

您只需要设置关联将用于:business_user的

的foreign_key

class BusinessUser < ActiveRecord::Base  
  has_many :business_places
end

class BusinessPlace < ActiveRecord::Base
  belongs_to :business_user, :foreign_key => 'BusinessUser_id'
end

Answer 2

你使用了错误的措辞。你的模型看起来应该是这样的：

class BusinessUser < ActiveRecord::Base  
  has_many :business_places
end

class BusinessPlace < ActiveRecord::Base
  belongs_to :business_user
end

所以基本上使用：business_places而不是：BusinessPlaces

如果使用迁移来设置数据库，则不需要修改外键

用两个单词创建模型

2 个答案: