Execute stored procedure

stored_procedure_service.rb

class StoredProcedureService

  def self.instance
    @instance ||= StoredProcedureService.new
  end

  def execute(name, *args)
    results = []
    begin
      connection.execute("CALL #{name}(#{args.join(',')})").each(as: :hash, symbolize_keys: true) do |row|
        results << OpenStruct.new(row)
      end
    ensure
      connection.close
    end
    results
  end

  def connection
    ActiveRecord::Base.connection
  end
end

I do it slightly differently, using the connection pool, and not instantiating the "service":

class DatabaseHelper
  def self.select name, *args, &blk
    execute "select", name, *args, &blk
  end

  def self.call name, *args, &blk
    execute "call", name, *args, &blk
  end

  def self.execute via, name, *args, &blk
    ActiveRecord::Base.connection_pool.with_connection do |connection|
      args = args.map{|e| connection.quote e}

      answer = connection.execute("#{via} #{name}(#{args.join(',')})").each(:as => :hash, :symbolize_keys => true) do |row|
        results << OpenStruct.new(row)
      end

      if blk
        blk.call(answer)
      else
        answer
      end
    end
  end
end