如何在rails中使用级联删除将列添加为外键

Question

I have two table one product and another usage

Product
#  id                  :integer          not null, primary key
#  product_name        :string           not null
#  plan_id             :string
#  plan_name           :string

Usage
#  id              :integer          not null, primary key
#  quantity        :float
#  date            :date

Want to add product_id as foreign key in usage

i am trying to run migration

 def change
    add_reference(:usages, :products, foreign_key: { on_delete: :cascade })
 end

Getting error column "product_id" referenced in foreign key constraint does not exist

Answer 1

解决方案是 ref_name 应该是单数

 add_reference(:usages, :product, foreign_key: { on_delete: :cascade })