在底部是我的代码。我有8列sku，价格1，价格2，价格3，最低价格，数量1，数量2，数量3数据库
我想在脚本中添加一些if语句来检查三个参数。如果数量>0
目前，我出口的价格从1-3最低的数字，但它没有检查是否有任何数量超过0。
这是我的密码：

<?php 
if (isset($_SERVER['REMOTE_ADDR'])) {
    die(':)');
}

echo "Cron is running";

$hostname   = 'localhost';
$username   = 'user';
$password   = 'pass';
$myDatabase = 'database';
/**
 * Defines the name of the table where data is to be inserted
 */
$table = 'mytable';

try {
    $conn = new PDO('mysql:host=localhost;dbname='.$myDatabase, $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);    

    $stmt = $conn->prepare("SELECT mytable.SKU AS SKU,  LEAST(price, price2, price3) AS 'Lowest2'
    FROM mytable
    ");

    $stmt->execute();

    $filelocation = 'assets/exports/';
    $filename     = 'export-'.date('Y-m-d H.i.s').'.csv';
    $file_export  =  $filelocation . $filename;

    $data = fopen($file_export, 'w');

    $csv_fields = array();

    $csv_fields[] = 'SKU';
    $csv_fields[] = 'Lowest2';

    fputcsv($data, $csv_fields);

    while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
        fputcsv($data, $row);
    }

} catch(PDOException $e) {
    echo 'ERROR: ' . $e->getMessage();
}