You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: 20230522090252_add_sku_to_product.rb
    path of file: ./repos/openfoodnetwork/db/migrate
    
    the code of the file until where you have to start completion: class AddSkuToProduct < ActiveRecord::Migration[7.0]
  def up
    add_column :spree_products, :sku, :s
    
  def migrate_master_sku
    ActiveRecord::Base.connection.execute(<<-SQL
      UPDATE spree_products
      SET sku = spree_variants.sku
      FROM spree_variants
      WHERE spree_variants.product_id = spree_products.id
        AND spree_variants.is_master = true
    SQL
    )
  end