亚马逊为aws广告api返回零价格

Question

我正在使用aws广告网络服务来销售亚马逊的产品，但我没有得到所有鞋类产品的价格。我不知道我哪里错了

http://webservices.amazon.in/onca/xml？

<?php
    //This script provides connection to the database//
    //Connect
    $user="root";
    $pass="";
    try {
        $connection = new PDO('mysql:host=localhost;dbname=thetest', $user, $pass);
    } catch (Exception $e) {
        print "Error!: " . $e->getMessage() . "<br/>";
    die();
    }

    //Insert
    try {
        $stmt = $connection->prepare("INSERT INTO `users`(`name`, `lastname`, `age`) VALUES(?,?,?)");
        $stmt->execute(array("Dave", "Smithers", "22"));
    } catch (Exception $e) {
        echo "Error!: " . $e->getMessage() . "<br/>";
        die();
    }

    //Fetch
    try {
        $stmt = $connection->prepare("SELECT `name` FROM `users` WHERE `lastname` = 'Smithers'");
        $result = $stmt->execute();
        $user = $result->fetchAll();
        print_r($user);
    } catch (Exception $e) {
        echo "Error!: " . $e->getMessage() . "<br/>";
    }
?>