Answers for "references in rails migration"

Add references rails migration

rails g migration AddUserToUploads user:references

Add references rails migration

class AddUserToUploads < ActiveRecord::Migration
  def change
    add_reference :uploads, :user, index: true
  end
end

using SQL in rails migration

def change
  execute <<-SQL
    UPDATE table1
    SET column1 = "value"
  SQL
end