def time_logs_query
    @query_logs ||= if params[:set_filter] == '2' || session[:tt_user_logs_query].nil?
      query = TimeLogQuery.new :name => 'x', :filters => {}
      query.build_from_params(params)
      session[:tt_user_logs_query] = {:filters => query.filters, :group_by => query.group_by, :column_names => query.column_names}