在Rails迁移中从模型调用方法？

Question

Super new to rails, but is it possible to call methods from a model in a migration?

Lets say I have a model that looks like:

class Orders < ApplicationRecord

   def order_size
      Order.where(item_id: 1).count
   end


   def order_level (order_size)
     if order_size =< 2
       Order.update_all(customer_level: "Bronze")
     elsif order_size >= 3 && order_size < 6
       Order.update_all(customer_level: "Silver")
     elsif order_size >= 6
       Order.update_all(customer_level: "Gold")
     end
   end

end

Could I run a migration that will only update certain size orders, such as:

class SomeMigration < ActiveRecord::Migration
    def change
       if order_size == 10
         (call/do order_level)
       end
    end
 end

Just for context, I've implemented a separate functionality that will automatically update an order's customer_level when a new order is created with order_level , but I need to go back and update all of the orders that already exist. I only really care about orders that are 10+ in this case.

Hope this makes sense and isn't completely ridiculous!

Thanks

Answer 1

is it possible to call methods from a model in a migration?

Yes. As illustrated in the docs, section 8 Migrations and Seed Data , you can call model methods in a migration. Here is the sample code from the docs:

class AddInitialProducts < ActiveRecord::Migration[5.0]
  def up
    5.times do |i|
      Product.create(name: "Product ##{i}", description: "A product.")
    end
  end

  def down
    Product.delete_all
  end
end

Whether it is a good idea or not is a separate question.