PDO-based stored procedure call in PHP

pdo_stored_procedure_call.php

<?php
// $db = new PDO($connection_string, $db_user, $db_password);

$plan_code = "PLAN_CODE";
$product_status = 200;
$page = 1;
$fetch = 20;
$qry = "CALL `db_billing`.`odp_cm_get_products`('$plan_code', $product_status, $page, $fetch, @total_row_count)";
$stm = $db->prepare($qry);
$stm->execute();
$rows = $stm->fetch();
$stm->closeCursor();
// fetch output params
$total_row_count = $db->query("select @total_row_count")->fetch(PDO::FETCH_ASSOC);
?>