Get SQL output from a Rails migration

migration_sql.rb

#!/usr/bin/env ruby

require_relative 'config/environment'

path = ARGV.shift || raise("specify migration as first argument")

require_relative path

filename = File.basename(path, ".rb")
timestamp, name = filename.split("_", 2)

name = name.camelcase

ActiveRecord::Migration.verbose = false

module Wrapper
  def execute(sql, *args)
    if sql =~ /^ALTER\ TABLE|((CREATE|DROP) (TABLE|VIEW))|INSERT|INDEX/i
      puts sql.gsub(/`/, '') + ";"
    else
      super
    end
  end
end

ActiveRecord::Base.connection # Needed to load Mysql2Adapter

ActiveRecord::ConnectionAdapters::Mysql2Adapter.prepend(Wrapper)

migration = name.constantize

migration.migrate(:up)

ActiveRecord::SchemaMigration.create!(:version => timestamp.to_s)

./migration_sql.rb db/migrate/20190523201104_add_index_to_wallets.rb