use ActiveRecord with in ruby script

ActiveRecord_connection.rb

require "active_record"

ActiveRecord::Base.establish_connection(
    :adapter => "postgresql",
    :host => "localhost",
    :username => "map",
    :password => "map",
    :database => "lspf"
)

#ActiveRecord::Base.connection.execute create_table_sql
class Edi < ActiveRecord::Base
  self.table_name = "cy_records_no_repeat"
end

class Ctn < ActiveRecord::Base
  self.table_name = "ctns"
end

arr = []
id_for_ctn = 1
Edi.order("ctn_no_ asc, oper_time_ desc").each do |edi|
  next if arr.include?(edi.ctn_no_)
  arr << edi.ctn_no_
  #Ctn.create(code: edi.ctn_no_f_, size: edi.ctn_size_f_id_, ctn_type: edi.ctn_type_f_name_, last_action_id: edi.id_)
  hash = {
      id_: id_for_ctn,
      code: edi.ctn_no_, size: edi.ctn_size_id_
  }
  Ctn.create hash
  id_for_ctn+=1
end

remove_connection.rb

class WaitPersisting < ActiveRecord::Base
end

while true
  puts "SolveUnpersistedData is running"
  begin
    id_arr = []
    WaitPersisting.establish_connection(
        :adapter => "postgresql",
        :host => "localhost",
        :username => "map",
        :password => "map",
        :database => "dev2"
    )
    WaitPersisting.where("created_at > ?", 5.days.ago).select("id").each do |id|
      id_arr << id
    end
    WaitPersisting.remove_connection

    unless id_arr.empty?
      uri = URI.parse("http://localhost:3000/inner_api/solve_un_persisted")
      result = Net::HTTP.post_form uri, :ids => id_arr.join
      if result.is_a? Net::HTTPOK
        logger.info "send successful:#{id_arr}"
      else
        logger.error "send failed:#{id_arr}"
      end
    end
    sleep 20
  rescue => e
    puts "Error in class SolveUnpersistedData: #{e.message}"
  end
end